From 50e7c23ae98e42fbc729baaa1500223af315a06b Mon Sep 17 00:00:00 2001
From: "Ava (Gaiety)" <165677673+gaiety-deque@users.noreply.github.com>
Date: Mon, 17 Jun 2024 06:09:26 -0500
Subject: [PATCH] chore(test/rule-matches): var -> const & let (#4497)

For `test/rule-matches`

Smaller part of the full vision:
https://github.com/dequelabs/axe-core/pull/4444
---
 .../rule-matches/aria-allowed-attr-matches.js |   8 +-
 .../rule-matches/aria-allowed-role-matches.js |  12 +-
 test/rule-matches/aria-has-attr-matches.js    |  12 +-
 .../rule-matches/aria-hidden-focus-matches.js |  20 +--
 .../aria-required-children-matches.js         |  10 +-
 .../aria-required-parent-matches.js           |  10 +-
 test/rule-matches/autocomplete-matches.js     |  40 ++---
 test/rule-matches/color-contrast-matches.js   | 140 +++++++++---------
 test/rule-matches/data-table-matches.js       |  12 +-
 .../duplicate-id-active-matches.js            |  22 +--
 .../rule-matches/duplicate-id-aria-matches.js |  22 +--
 .../rule-matches/duplicate-id-misc-matches.js |  22 +--
 .../frame-focusable-content-matches.js        |  12 +-
 .../frame-title-has-text-matches.js           |  10 +-
 .../has-implicit-chromium-role-matches.js     |  14 +-
 test/rule-matches/heading-matches.js          |  24 +--
 test/rule-matches/html-namespace-matches.js   |  30 ++--
 test/rule-matches/html-xml-lang-mismatch.js   |  18 +--
 .../identical-links-same-purpose-matches.js   |  48 +++---
 .../inserted-into-focus-order-matches.js      |  16 +-
 test/rule-matches/is-initiator-matches.js     |   4 +-
 test/rule-matches/is-visible-matches.js       |   6 +-
 .../label-content-name-mismatch-matches.js    |  74 ++++-----
 test/rule-matches/label-matches.js            |  16 +-
 .../rule-matches/landmark-has-body-context.js |  18 +--
 test/rule-matches/landmark-unique-matches.js  |  83 ++++++-----
 test/rule-matches/layout-table-matches.js     |  14 +-
 .../nested-interactive-matches.js             |  14 +-
 .../rule-matches/no-autoplay-audio-matches.js |  20 +--
 test/rule-matches/no-empty-role-matches.js    |  36 ++---
 .../no-explicit-name-required-matches.js      |  34 ++---
 test/rule-matches/no-naming-method-matches.js |  50 +++----
 test/rule-matches/no-negative-tabindex.js     |  26 ++--
 test/rule-matches/p-as-heading-matches.js     |  18 +--
 .../scrollable-region-focusable-matches.js    |  88 +++++------
 test/rule-matches/skip-link-matches.js        |   4 +-
 test/rule-matches/svg-namespace-matches.js    |  36 ++---
 37 files changed, 527 insertions(+), 516 deletions(-)

diff --git a/test/rule-matches/aria-allowed-attr-matches.js b/test/rule-matches/aria-allowed-attr-matches.js
index 5b7dfb33a6..e4177e0f78 100644
--- a/test/rule-matches/aria-allowed-attr-matches.js
+++ b/test/rule-matches/aria-allowed-attr-matches.js
@@ -1,8 +1,8 @@
 describe('aria-allowed-attr-matches', function () {
   'use strict';
 
-  var queryFixture = axe.testUtils.queryFixture;
-  var rule;
+  const queryFixture = axe.testUtils.queryFixture;
+  let rule;
 
   beforeEach(function () {
     rule = axe.utils.getRule('aria-allowed-attr');
@@ -13,7 +13,7 @@ describe('aria-allowed-attr-matches', function () {
   });
 
   it('should return true on elements that have aria attributes', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<div role="button" id="target" aria-label="Thing 1" aria-mccheddarton="Unsupported thing 2"></div>'
     );
 
@@ -21,7 +21,7 @@ describe('aria-allowed-attr-matches', function () {
   });
 
   it('should return false on elements that have no aria attributes', function () {
-    var vNode = queryFixture('<div role="button" id="target"></div>');
+    const vNode = queryFixture('<div role="button" id="target"></div>');
 
     assert.isFalse(rule.matches(null, vNode));
   });
diff --git a/test/rule-matches/aria-allowed-role-matches.js b/test/rule-matches/aria-allowed-role-matches.js
index 28992fde4c..14769d0d77 100644
--- a/test/rule-matches/aria-allowed-role-matches.js
+++ b/test/rule-matches/aria-allowed-role-matches.js
@@ -1,27 +1,29 @@
 describe('aria-allowed-role-matches', function () {
   'use strict';
 
-  var queryFixture = axe.testUtils.queryFixture;
-  var rule;
+  const queryFixture = axe.testUtils.queryFixture;
+  let rule;
 
   beforeEach(function () {
     rule = axe.utils.getRule('aria-allowed-role');
   });
 
   it('return false (no matches) for a <link> with a href to have any invalid role', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<link id="target" href="/example.com" role="invalid-role"></link>'
     );
     assert.isFalse(rule.matches(null, vNode));
   });
 
   it('return true for input with redundant role', function () {
-    var vNode = queryFixture('<input id="target" type="text" role="textbox"/>');
+    const vNode = queryFixture(
+      '<input id="target" type="text" role="textbox"/>'
+    );
     assert.isTrue(rule.matches(null, vNode));
   });
 
   it('return true for element with valid role', function () {
-    var vNode = queryFixture('<ol id="target" role="listbox"/>');
+    const vNode = queryFixture('<ol id="target" role="listbox"/>');
     assert.isTrue(rule.matches(null, vNode));
   });
 });
diff --git a/test/rule-matches/aria-has-attr-matches.js b/test/rule-matches/aria-has-attr-matches.js
index c3e0adbb52..a724a68a0a 100644
--- a/test/rule-matches/aria-has-attr-matches.js
+++ b/test/rule-matches/aria-has-attr-matches.js
@@ -1,9 +1,9 @@
 describe('aria-has-attr-matches', function () {
   'use strict';
 
-  var queryFixture = axe.testUtils.queryFixture;
-  var fixtureSetup = axe.testUtils.fixtureSetup;
-  var rule;
+  const queryFixture = axe.testUtils.queryFixture;
+  const fixtureSetup = axe.testUtils.fixtureSetup;
+  let rule;
 
   beforeEach(function () {
     rule = axe.utils.getRule('aria-valid-attr-value');
@@ -14,16 +14,16 @@ describe('aria-has-attr-matches', function () {
   });
 
   it('should return false if an element has no attributes', function () {
-    var vNode = fixtureSetup('<div></div>');
+    const vNode = fixtureSetup('<div></div>');
     assert.isFalse(rule.matches(null, vNode));
   });
 
   it('should return false if an element has no ARIA attributes', function () {
-    var vNode = queryFixture('<div id="target"></div>');
+    const vNode = queryFixture('<div id="target"></div>');
     assert.isFalse(rule.matches(null, vNode));
   });
   it('should return true if an element has ARIA attributes', function () {
-    var vNode = queryFixture('<div id="target" aria-bats="monkeys"></div>');
+    const vNode = queryFixture('<div id="target" aria-bats="monkeys"></div>');
     assert.isTrue(rule.matches(null, vNode));
   });
 });
diff --git a/test/rule-matches/aria-hidden-focus-matches.js b/test/rule-matches/aria-hidden-focus-matches.js
index b770c88323..0a498004af 100644
--- a/test/rule-matches/aria-hidden-focus-matches.js
+++ b/test/rule-matches/aria-hidden-focus-matches.js
@@ -1,8 +1,8 @@
 describe('aria-hidden-focus-matches', function () {
   'use strict';
 
-  var rule;
-  var queryFixture = axe.testUtils.queryFixture;
+  let rule;
+  const queryFixture = axe.testUtils.queryFixture;
 
   beforeEach(function () {
     rule = axe.utils.getRule('aria-hidden-focus');
@@ -13,24 +13,24 @@ describe('aria-hidden-focus-matches', function () {
   });
 
   it('return true when there is no parent with aria-hidden', function () {
-    var vNode = queryFixture('<div id="target">' + '</div>');
-    var actual = rule.matches(vNode.actualNode);
+    const vNode = queryFixture('<div id="target">' + '</div>');
+    const actual = rule.matches(vNode.actualNode);
     assert.isTrue(actual);
   });
 
   it('return false when has a parent element with aria-hidden', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<div aria-hidden="true">' +
         '<div id="target" aria-hidden="true">' +
         '</div>' +
         '</div>'
     );
-    var actual = rule.matches(vNode.actualNode);
+    const actual = rule.matches(vNode.actualNode);
     assert.isFalse(actual);
   });
 
   it('return false when has any parent element with aria-hidden', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<div aria-hidden="true">' +
         '<div>' +
         '<div id="target" aria-hidden="true">' +
@@ -38,19 +38,19 @@ describe('aria-hidden-focus-matches', function () {
         '</div>' +
         '</div>'
     );
-    var actual = rule.matches(vNode.actualNode);
+    const actual = rule.matches(vNode.actualNode);
     assert.isFalse(actual);
   });
 
   it('return false when has any parent element with aria-hidden', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<div aria-hidden="true">' +
         '<div aria-hidden="true">' +
         '<button id="target">btn</button>' +
         '</div>' +
         '</div>'
     );
-    var actual = rule.matches(vNode.actualNode);
+    const actual = rule.matches(vNode.actualNode);
     assert.isFalse(actual);
   });
 });
diff --git a/test/rule-matches/aria-required-children-matches.js b/test/rule-matches/aria-required-children-matches.js
index 319e7845b2..200b3c0094 100644
--- a/test/rule-matches/aria-required-children-matches.js
+++ b/test/rule-matches/aria-required-children-matches.js
@@ -1,9 +1,9 @@
 describe('aria-required-children-matches', function () {
   'use strict';
 
-  var fixture = document.getElementById('fixture');
-  var queryFixture = axe.testUtils.queryFixture;
-  var rule;
+  const fixture = document.getElementById('fixture');
+  const queryFixture = axe.testUtils.queryFixture;
+  let rule;
 
   beforeEach(function () {
     rule = axe.utils.getRule('aria-required-children');
@@ -14,12 +14,12 @@ describe('aria-required-children-matches', function () {
   });
 
   it('should return true for a role that requires children', function () {
-    var vNode = queryFixture('<div id="target" role="list"></div>');
+    const vNode = queryFixture('<div id="target" role="list"></div>');
     assert.isTrue(rule.matches(null, vNode));
   });
 
   it('should return false for a role that does not require children', function () {
-    var vNode = queryFixture('<div id="target" role="alert"></div>');
+    const vNode = queryFixture('<div id="target" role="alert"></div>');
     assert.isFalse(rule.matches(null, vNode));
   });
 });
diff --git a/test/rule-matches/aria-required-parent-matches.js b/test/rule-matches/aria-required-parent-matches.js
index 53f380839e..ceeb1bad59 100644
--- a/test/rule-matches/aria-required-parent-matches.js
+++ b/test/rule-matches/aria-required-parent-matches.js
@@ -1,9 +1,9 @@
 describe('aria-required-parent-matches', function () {
   'use strict';
 
-  var fixture = document.getElementById('fixture');
-  var queryFixture = axe.testUtils.queryFixture;
-  var rule;
+  const fixture = document.getElementById('fixture');
+  const queryFixture = axe.testUtils.queryFixture;
+  let rule;
 
   beforeEach(function () {
     rule = axe.utils.getRule('aria-required-parent');
@@ -14,12 +14,12 @@ describe('aria-required-parent-matches', function () {
   });
 
   it('should return true for a role that requires parent', function () {
-    var vNode = queryFixture('<div id="target" role="listitem"></div>');
+    const vNode = queryFixture('<div id="target" role="listitem"></div>');
     assert.isTrue(rule.matches(null, vNode));
   });
 
   it('should return false for a role that does not require parent', function () {
-    var vNode = queryFixture('<div id="target" role="alert"></div>');
+    const vNode = queryFixture('<div id="target" role="alert"></div>');
     assert.isFalse(rule.matches(null, vNode));
   });
 });
diff --git a/test/rule-matches/autocomplete-matches.js b/test/rule-matches/autocomplete-matches.js
index 7c914c39b2..9f21885939 100644
--- a/test/rule-matches/autocomplete-matches.js
+++ b/test/rule-matches/autocomplete-matches.js
@@ -1,8 +1,8 @@
 describe('autocomplete-matches', function () {
   'use strict';
-  var fixture = document.getElementById('fixture');
-  var queryFixture = axe.testUtils.queryFixture;
-  var rule = axe.utils.getRule('autocomplete-valid');
+  const fixture = document.getElementById('fixture');
+  const queryFixture = axe.testUtils.queryFixture;
+  const rule = axe.utils.getRule('autocomplete-valid');
 
   afterEach(function () {
     fixture.innerHTML = '';
@@ -13,33 +13,33 @@ describe('autocomplete-matches', function () {
   });
 
   it('returns true for input elements', function () {
-    var vNode = queryFixture('<input id="target" autocomplete="foo">');
+    const vNode = queryFixture('<input id="target" autocomplete="foo">');
     assert.isTrue(rule.matches(null, vNode));
   });
 
   it('returns true for select elements', function () {
-    var vNode = queryFixture('<select id="target" autocomplete="foo">');
+    const vNode = queryFixture('<select id="target" autocomplete="foo">');
     assert.isTrue(rule.matches(null, vNode));
   });
 
   it('returns true for textarea elements', function () {
-    var vNode = queryFixture('<textarea id="target" autocomplete="foo">');
+    const vNode = queryFixture('<textarea id="target" autocomplete="foo">');
     assert.isTrue(rule.matches(null, vNode));
   });
 
   it('returns false for buttons elements', function () {
-    var vNode = queryFixture('<button id="target" autocomplete="foo">');
+    const vNode = queryFixture('<button id="target" autocomplete="foo">');
     assert.isFalse(rule.matches(null, vNode));
   });
 
   it('should return false for non-form field elements', function () {
-    var vNode = queryFixture('<div id="target" autocomplete="foo">');
+    const vNode = queryFixture('<div id="target" autocomplete="foo">');
     assert.isFalse(rule.matches(null, vNode));
   });
 
   it('returns false for input buttons', function () {
     ['reset', 'submit', 'button'].forEach(function (type) {
-      var vNode = queryFixture(
+      const vNode = queryFixture(
         '<input id="target" type="' + type + '" autocomplete="foo">'
       );
       assert.isFalse(rule.matches(null, vNode));
@@ -47,12 +47,12 @@ describe('autocomplete-matches', function () {
   });
 
   it('returns false for elements with an empty autocomplete', function () {
-    var vNode = queryFixture('<input id="target" autocomplete="  ">');
+    const vNode = queryFixture('<input id="target" autocomplete="  ">');
     assert.isFalse(rule.matches(null, vNode));
   });
 
   it('returns false for intput[type=hidden]', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<input id="target" type="hidden" autocomplete="foo">'
     );
     assert.isFalse(rule.matches(null, vNode));
@@ -60,7 +60,7 @@ describe('autocomplete-matches', function () {
 
   it('returns false for disabled fields', function () {
     ['input', 'select', 'textarea'].forEach(function (tagName) {
-      var vNode = queryFixture(
+      const vNode = queryFixture(
         '<' + tagName + ' id="target" disabled autocomplete="foo">'
       );
       assert.isFalse(rule.matches(null, vNode));
@@ -69,7 +69,7 @@ describe('autocomplete-matches', function () {
 
   it('returns false for aria-disabled=true fields', function () {
     ['input', 'select', 'textarea'].forEach(function (tagName) {
-      var vNode = queryFixture(
+      const vNode = queryFixture(
         '<' + tagName + ' id="target" aria-disabled="true" autocomplete="foo">'
       );
       assert.isFalse(rule.matches(null, vNode));
@@ -78,7 +78,7 @@ describe('autocomplete-matches', function () {
 
   it('returns true for aria-disabled=false fields', function () {
     ['input', 'select', 'textarea'].forEach(function (tagName) {
-      var vNode = queryFixture(
+      const vNode = queryFixture(
         '<' + tagName + ' id="target" aria-disabled="false" autocomplete="foo">'
       );
       assert.isTrue(rule.matches(null, vNode));
@@ -86,9 +86,9 @@ describe('autocomplete-matches', function () {
   });
 
   it('returns false for non-widget roles with tabindex=-1', function () {
-    var nonWidgetRoles = ['application', 'fakerole', 'main'];
+    const nonWidgetRoles = ['application', 'fakerole', 'main'];
     nonWidgetRoles.forEach(function (role) {
-      var vNode = queryFixture(
+      const vNode = queryFixture(
         '<input id="target" role="' +
           role +
           '" tabindex="-1" autocomplete="foo">'
@@ -101,9 +101,9 @@ describe('autocomplete-matches', function () {
   });
 
   it('returns true for form fields with a widget role with tabindex=-1', function () {
-    var nonWidgetRoles = ['button', 'menuitem', 'slider'];
+    const nonWidgetRoles = ['button', 'menuitem', 'slider'];
     nonWidgetRoles.forEach(function (role) {
-      var vNode = queryFixture(
+      const vNode = queryFixture(
         '<input id="target" role="' +
           role +
           '" tabindex="-1" autocomplete="foo">'
@@ -114,7 +114,7 @@ describe('autocomplete-matches', function () {
 
   it('returns true for form fields with tabindex=-1', function () {
     ['input', 'select', 'textarea'].forEach(function (tagName) {
-      var vNode = queryFixture(
+      const vNode = queryFixture(
         '<' + tagName + ' id="target" tabindex="-1" autocomplete="foo">'
       );
       assert.isTrue(rule.matches(null, vNode));
@@ -122,7 +122,7 @@ describe('autocomplete-matches', function () {
   });
 
   it('returns false for off screen and hidden form fields with tabindex=-1', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<div aria-hidden="true">' +
         '<input id="target" tabindex="-1" style="position:absolute; top:-9999em" autocomplete="foo">' +
         '</div>'
diff --git a/test/rule-matches/color-contrast-matches.js b/test/rule-matches/color-contrast-matches.js
index fc41e301ee..3688e5b357 100644
--- a/test/rule-matches/color-contrast-matches.js
+++ b/test/rule-matches/color-contrast-matches.js
@@ -1,10 +1,10 @@
 describe('color-contrast-matches', function () {
   'use strict';
 
-  var fixture = document.getElementById('fixture');
-  var shadowSupport =
+  const fixture = document.getElementById('fixture');
+  const shadowSupport =
     document.body && typeof document.body.attachShadow === 'function';
-  var rule;
+  let rule;
 
   beforeEach(function () {
     rule = axe.utils.getRule('color-contrast');
@@ -23,7 +23,7 @@ describe('color-contrast-matches', function () {
     fixture.innerHTML =
       '<div style="color: yellow; background-color: white;" id="target">' +
       ' </div>';
-    var target = fixture.querySelector('#target');
+    const target = fixture.querySelector('#target');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
@@ -32,7 +32,7 @@ describe('color-contrast-matches', function () {
     fixture.innerHTML =
       '<div style="color: yellow; background-color: white;" id="target">' +
       'My text</div>';
-    var target = fixture.querySelector('#target');
+    const target = fixture.querySelector('#target');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isTrue(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
@@ -41,7 +41,7 @@ describe('color-contrast-matches', function () {
     fixture.innerHTML =
       '<div style="color: yellow; background-color: white;" id="target">' +
       '🌎</div>';
-    var target = fixture.querySelector('#target');
+    const target = fixture.querySelector('#target');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
@@ -50,7 +50,7 @@ describe('color-contrast-matches', function () {
     fixture.innerHTML =
       '<div style="color: yellow; background-color: white;" id="target">' +
       '&rlm;</div>';
-    var target = fixture.querySelector('#target');
+    const target = fixture.querySelector('#target');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
@@ -59,7 +59,7 @@ describe('color-contrast-matches', function () {
     fixture.innerHTML =
       '<div style="color: yellow; background-color: white;" id="target">' +
       '◓</div>';
-    var target = fixture.querySelector('#target');
+    const target = fixture.querySelector('#target');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isTrue(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
@@ -68,7 +68,7 @@ describe('color-contrast-matches', function () {
     fixture.innerHTML =
       '<div style="color: yellow; text-indent: -9999px; background-color: white;" id="target">' +
       'My text</div>';
-    var target = fixture.querySelector('#target');
+    const target = fixture.querySelector('#target');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
@@ -76,7 +76,7 @@ describe('color-contrast-matches', function () {
   it('should not match input when there is text that is out of the container', function () {
     fixture.innerHTML =
       '<input style="text-indent: -9999px" type="submit" value="Search" />';
-    var target = fixture.querySelector('input');
+    const target = fixture.querySelector('input');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
@@ -86,7 +86,7 @@ describe('color-contrast-matches', function () {
       '<select style="text-indent: -9999px">' +
       '<option selected>My text</option>' +
       '</select>';
-    var target = fixture.querySelector('select');
+    const target = fixture.querySelector('select');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
@@ -94,7 +94,7 @@ describe('color-contrast-matches', function () {
   it('should not match textarea when there is text that is out of the container', function () {
     fixture.innerHTML =
       '<textarea style="text-indent: -9999px">My text</textarea>';
-    var target = fixture.querySelector('textarea');
+    const target = fixture.querySelector('textarea');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
@@ -103,7 +103,7 @@ describe('color-contrast-matches', function () {
     fixture.innerHTML =
       '<div style="color: yellow; width: 100px; overflow: hidden; text-indent: 200px; background-color: white;" id="target">' +
       'text</div>';
-    var target = fixture.querySelector('#target');
+    const target = fixture.querySelector('#target');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
@@ -112,7 +112,7 @@ describe('color-contrast-matches', function () {
     fixture.innerHTML =
       '<div style="color: yellow; width: 100px; overflow: scroll; text-indent: 200px; background-color: white;" id="target">' +
       'text</div>';
-    var target = fixture.querySelector('#target');
+    const target = fixture.querySelector('#target');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isTrue(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
@@ -121,42 +121,42 @@ describe('color-contrast-matches', function () {
     fixture.innerHTML =
       '<div style="color: yellow; text-indent: -20px; background-color: white;" id="target">' +
       'My text</div>';
-    var target = fixture.querySelector('#target');
+    const target = fixture.querySelector('#target');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isTrue(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
 
   it('should match <input type="text">', function () {
     fixture.innerHTML = '<input type="text">';
-    var target = fixture.querySelector('input');
+    const target = fixture.querySelector('input');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isTrue(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
 
   it('should not match <input type="hidden">', function () {
     fixture.innerHTML = '<input type="hidden">';
-    var target = fixture.querySelector('input');
+    const target = fixture.querySelector('input');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
 
   it('should not match <input type="checkbox">', function () {
     fixture.innerHTML = '<input type="checkbox">';
-    var target = fixture.querySelector('input');
+    const target = fixture.querySelector('input');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
 
   it('should not match <input type="radio">', function () {
     fixture.innerHTML = '<input type="radio">';
-    var target = fixture.querySelector('input');
+    const target = fixture.querySelector('input');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
 
   it('should not match <input type="color">', function () {
     fixture.innerHTML = '<input type="color">';
-    var target = fixture.querySelector('input');
+    const target = fixture.querySelector('input');
     axe.testUtils.flatTreeSetup(fixture);
     // Some browsers will fallback to type=text for unknown input types (looking at you IE)
     if (target.type === 'color') {
@@ -166,7 +166,7 @@ describe('color-contrast-matches', function () {
 
   it('should not match <input type="range">', function () {
     fixture.innerHTML = '<input type="range">';
-    var target = fixture.querySelector('input');
+    const target = fixture.querySelector('input');
     axe.testUtils.flatTreeSetup(fixture);
     // Some browsers will fallback to type=text for unknown input types (looking at you IE)
     if (target.type === 'range') {
@@ -176,35 +176,35 @@ describe('color-contrast-matches', function () {
 
   it('should match <select> with options', function () {
     fixture.innerHTML = '<select><option>Hello</option></select>';
-    var target = fixture.querySelector('select');
+    const target = fixture.querySelector('select');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isTrue(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
 
   it('should not match <select> with no options', function () {
     fixture.innerHTML = '<select></select>';
-    var target = fixture.querySelector('select');
+    const target = fixture.querySelector('select');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
 
   it('should match <textarea>', function () {
     fixture.innerHTML = '<textarea></textarea>';
-    var target = fixture.querySelector('textarea');
+    const target = fixture.querySelector('textarea');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isTrue(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
 
   it('should not match <option>', function () {
     fixture.innerHTML = '<select><option>hi</option></select>';
-    var target = fixture.querySelector('option');
+    const target = fixture.querySelector('option');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
 
   it('should not match inputs that are disabled', function () {
     fixture.innerHTML = '<input type="text" disabled>';
-    var target = fixture.querySelector('input');
+    const target = fixture.querySelector('input');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
@@ -216,43 +216,43 @@ describe('color-contrast-matches', function () {
       '<span style="background-color:rgba(0, 0, 0, 0.26);display:inline-block;width: 1.5rem;height: 1.5rem;" aria-hidden="true"></span>' +
       '<span style="color:rgba(0, 0, 0, 0.38);" id="target">Baseball</span>' +
       '</label>';
-    var target = fixture.querySelector('#target');
+    const target = fixture.querySelector('#target');
     axe.testUtils.flatTreeSetup(fixture);
-    var result = rule.matches(target, axe.utils.getNodeFromTree(target));
+    const result = rule.matches(target, axe.utils.getNodeFromTree(target));
     assert.isFalse(result);
   });
 
   it('should not match <textarea disabled>', function () {
     fixture.innerHTML = '<textarea disabled></textarea>';
-    var target = fixture.querySelector('textarea');
+    const target = fixture.querySelector('textarea');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
 
   it('should not match <select> with options', function () {
     fixture.innerHTML = '<select disabled><option>Hello</option></select>';
-    var target = fixture.querySelector('select');
+    const target = fixture.querySelector('select');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
 
   it('should match <button>', function () {
     fixture.innerHTML = '<button>hi</button>';
-    var target = fixture.querySelector('button');
+    const target = fixture.querySelector('button');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isTrue(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
 
   it('should not match <button disabled>', function () {
     fixture.innerHTML = '<button disabled>hi</button>';
-    var target = fixture.querySelector('button');
+    const target = fixture.querySelector('button');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
 
   it('should not match <button disabled><span></span></button>', function () {
     fixture.innerHTML = '<button disabled><span>Hi</span></button>';
-    var target = fixture.querySelector('button');
+    const target = fixture.querySelector('button');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(
       rule.matches(
@@ -264,7 +264,7 @@ describe('color-contrast-matches', function () {
 
   it('should not match <button disabled><span><i></i></span></button>', function () {
     fixture.innerHTML = '<button disabled><span><i>Hi</i></span></button>';
-    var target = fixture.querySelector('button');
+    const target = fixture.querySelector('button');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(
       rule.matches(
@@ -276,7 +276,7 @@ describe('color-contrast-matches', function () {
 
   it('should not match <input type=image>', function () {
     fixture.innerHTML = '<input type="image">';
-    var target = fixture.querySelector('input');
+    const target = fixture.querySelector('input');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
@@ -284,7 +284,7 @@ describe('color-contrast-matches', function () {
   it("should not match a disabled input's label - explicit label", function () {
     fixture.innerHTML =
       '<label for="t1">Test</label><input type="text" id="t1" disabled>';
-    var target = fixture.querySelector('label');
+    const target = fixture.querySelector('label');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
@@ -292,7 +292,7 @@ describe('color-contrast-matches', function () {
   it("should not match an aria-disabled input's label - explicit label", function () {
     fixture.innerHTML =
       '<label for="t1">Test</label><input type="text" id="t1" aria-disabled="true">';
-    var target = fixture.querySelector('label');
+    const target = fixture.querySelector('label');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
@@ -300,21 +300,21 @@ describe('color-contrast-matches', function () {
   it("should not match a parent aria-disabled input's label - explicit label", function () {
     fixture.innerHTML =
       '<label for="t1">Test</label><div aria-disabled="true"><input type="text" id="t1"></div>';
-    var target = fixture.querySelector('label');
+    const target = fixture.querySelector('label');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
 
   it("should not match a disabled input's label - implicit label (input)", function () {
     fixture.innerHTML = '<label>Test<input type="text" disabled></label>';
-    var target = fixture.querySelector('label');
+    const target = fixture.querySelector('label');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
 
   it("should not match a disabled input's label - implicit label (textarea)", function () {
     fixture.innerHTML = '<label>Test<textarea disabled>Hi</textarea></label>';
-    var target = fixture.querySelector('label');
+    const target = fixture.querySelector('label');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
@@ -322,7 +322,7 @@ describe('color-contrast-matches', function () {
   it("should not match a disabled input's label - implicit label (select)", function () {
     fixture.innerHTML =
       '<label>Test<select disabled><option>Test</option></select></label>';
-    var target = fixture.querySelector('label');
+    const target = fixture.querySelector('label');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
@@ -330,7 +330,7 @@ describe('color-contrast-matches', function () {
   it("should not match a disabled input's label - aria-labelledby", function () {
     fixture.innerHTML =
       '<div id="t1">Test</div><input type="text" aria-labelledby="bob t1 fred" disabled>';
-    var target = fixture.querySelector('div');
+    const target = fixture.querySelector('div');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
@@ -340,7 +340,7 @@ describe('color-contrast-matches', function () {
       '<div id="t1">Test</div>' +
       '<input type="text" aria-labelledby="t1" disabled />' +
       '<input type="text" aria-labelledby="t1" />';
-    var target = fixture.querySelector('div');
+    const target = fixture.querySelector('div');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isTrue(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
@@ -352,21 +352,21 @@ describe('color-contrast-matches', function () {
       '<input type="text" aria-labelledby="t1" />' +
       '<input type="text" aria-labelledby="t1" />' +
       '</fieldset>';
-    var target = fixture.querySelector('div');
+    const target = fixture.querySelector('div');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
 
   it('should not match aria-disabled=true', function () {
     fixture.innerHTML = '<div aria-disabled="true">hi</div>';
-    var target = fixture.querySelector('div');
+    const target = fixture.querySelector('div');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
 
   it('should not match a descendant of aria-disabled=true', function () {
     fixture.innerHTML = '<div aria-disabled="true"><span>hi</span></div>';
-    var target = fixture.querySelector('span');
+    const target = fixture.querySelector('span');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
@@ -375,7 +375,7 @@ describe('color-contrast-matches', function () {
     fixture.innerHTML =
       '<div id="t1"><span>Test</span></div>' +
       '<div role="textbox" aria-labelledby="bob t1 fred" aria-disabled="true"></div>';
-    var target = fixture.querySelector('span');
+    const target = fixture.querySelector('span');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
@@ -383,7 +383,7 @@ describe('color-contrast-matches', function () {
   it('should not match a descendant of a disabled fieldset', function () {
     fixture.innerHTML =
       '<fieldset disabled><label>hi <input type="checkbox"></label></fieldset>';
-    var target = fixture.querySelector('label');
+    const target = fixture.querySelector('label');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
@@ -391,7 +391,7 @@ describe('color-contrast-matches', function () {
   it('should not match a descendant of an explicit label for a disabled input', function () {
     fixture.innerHTML =
       '<input id="input" type="checkbox" disabled><label for="input"><span>hi</span></label>';
-    var target = fixture.querySelector('span');
+    const target = fixture.querySelector('span');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
@@ -399,21 +399,21 @@ describe('color-contrast-matches', function () {
   it('should not match a descendant of an implicit label for a disabled input', function () {
     fixture.innerHTML =
       '<label for="input"><span>hi</span><input id="input" type="checkbox" disabled></label>';
-    var target = fixture.querySelector('span');
+    const target = fixture.querySelector('span');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
 
   it('should not match inert', function () {
     fixture.innerHTML = '<div inert>hi</div>';
-    var target = fixture.querySelector('div');
+    const target = fixture.querySelector('div');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
 
   it('should not match a descendant of inert', function () {
     fixture.innerHTML = '<div inert><span>hi</span></div>';
-    var target = fixture.querySelector('span');
+    const target = fixture.querySelector('span');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
@@ -426,7 +426,7 @@ describe('color-contrast-matches', function () {
         </div>
       </div>
     `;
-    var target = fixture.querySelector('#target');
+    const target = fixture.querySelector('#target');
     axe.testUtils.flatTreeSetup(fixture);
     assert.isFalse(rule.matches(target, axe.utils.getNodeFromTree(target)));
   });
@@ -436,13 +436,13 @@ describe('color-contrast-matches', function () {
       fixture.innerHTML =
         '<div id="parent" style="background-color: #000;">' + '</div>';
 
-      var shadowRoot = document
+      const shadowRoot = document
         .getElementById('parent')
         .attachShadow({ mode: 'open' });
       shadowRoot.innerHTML =
         '<div id="shadowTarget" style="color: #333">Text</div>';
 
-      var shadowTarget =
+      const shadowTarget =
         fixture.firstChild.shadowRoot.querySelector('#shadowTarget');
       axe.testUtils.flatTreeSetup(fixture);
       assert.isTrue(
@@ -453,7 +453,7 @@ describe('color-contrast-matches', function () {
     it('should look at the correct root node when looking up an explicit label and disabled input', function () {
       fixture.innerHTML = '<div id="parent">' + '<input id="input">' + '</div>';
 
-      var shadowRoot = document
+      const shadowRoot = document
         .getElementById('parent')
         .attachShadow({ mode: 'open' });
       shadowRoot.innerHTML =
@@ -462,7 +462,7 @@ describe('color-contrast-matches', function () {
         '<input id="input" disabled>' +
         '</div>';
 
-      var shadowLabel =
+      const shadowLabel =
         fixture.firstChild.shadowRoot.querySelector('#shadowLabel');
       axe.testUtils.flatTreeSetup(fixture);
       assert.isFalse(
@@ -473,7 +473,7 @@ describe('color-contrast-matches', function () {
     it('should look at the correct root node when looking up implicit label and disabled input', function () {
       fixture.innerHTML = '<div id="parent">' + '<input>' + '</div>';
 
-      var shadowRoot = document
+      const shadowRoot = document
         .getElementById('parent')
         .attachShadow({ mode: 'open' });
       shadowRoot.innerHTML =
@@ -481,7 +481,7 @@ describe('color-contrast-matches', function () {
         '<label id="shadowLabel">Label <input disabled></label>' +
         '</div>';
 
-      var shadowLabel =
+      const shadowLabel =
         fixture.firstChild.shadowRoot.querySelector('#shadowLabel');
       axe.testUtils.flatTreeSetup(fixture);
       assert.isFalse(
@@ -492,7 +492,7 @@ describe('color-contrast-matches', function () {
     it("should look at the correct root node for a disabled control's label associated w/ aria-labelledby", function () {
       fixture.innerHTML = '<div id="parent">' + '<input id="input">' + '</div>';
 
-      var shadowRoot = document
+      const shadowRoot = document
         .getElementById('parent')
         .attachShadow({ mode: 'open' });
       shadowRoot.innerHTML =
@@ -501,7 +501,7 @@ describe('color-contrast-matches', function () {
         '<input aria-labelledby="shadowLabel" disabled>' +
         '</div>';
 
-      var shadowLabel =
+      const shadowLabel =
         fixture.firstChild.shadowRoot.querySelector('#shadowLabel');
       axe.testUtils.flatTreeSetup(fixture);
       assert.isFalse(
@@ -512,11 +512,11 @@ describe('color-contrast-matches', function () {
     it('should handle input/label spread across the shadow boundary', function () {
       fixture.innerHTML = '<label>Text <div id="firstChild"></div></label>';
 
-      var container = document.getElementById('firstChild');
-      var shadowRoot = container.attachShadow({ mode: 'open' });
+      const container = document.getElementById('firstChild');
+      const shadowRoot = container.attachShadow({ mode: 'open' });
       shadowRoot.innerHTML = '<input type="text" id="input" disabled />';
 
-      var shadowTarget = container.shadowRoot.querySelector('#input');
+      const shadowTarget = container.shadowRoot.querySelector('#input');
       axe.testUtils.flatTreeSetup(fixture);
       assert.isFalse(
         rule.matches(shadowTarget, axe.utils.getNodeFromTree(shadowTarget))
@@ -529,14 +529,14 @@ describe('color-contrast-matches', function () {
         '<div id="firstChild" style="background-color: #ccc; color: #fff;"></div>' +
         '</div>';
 
-      var shadowRoot = document
+      const shadowRoot = document
         .getElementById('firstChild')
         .attachShadow({ mode: 'open' });
       shadowRoot.innerHTML =
         'Some text' +
         '<p style="color: #fff;" id="shadowTarget">Other text</p>';
 
-      var firstChild = fixture.querySelector('#firstChild');
+      const firstChild = fixture.querySelector('#firstChild');
       axe.testUtils.flatTreeSetup(fixture);
       assert.isTrue(
         rule.matches(firstChild, axe.utils.getNodeFromTree(firstChild))
@@ -550,16 +550,16 @@ describe('color-contrast-matches', function () {
         '</span></label>';
 
       function createContentSlotted() {
-        var group = document.createElement('span');
+        const group = document.createElement('span');
         group.innerHTML = '<slot></slot>';
         return group;
       }
 
-      var slotted = fixture.querySelector('.slotted');
-      var shadowRoot = slotted.attachShadow({ mode: 'open' });
+      const slotted = fixture.querySelector('.slotted');
+      const shadowRoot = slotted.attachShadow({ mode: 'open' });
       shadowRoot.appendChild(createContentSlotted());
 
-      var input = slotted.querySelector('input');
+      const input = slotted.querySelector('input');
       axe.testUtils.flatTreeSetup(fixture);
       assert.isTrue(rule.matches(input, axe.utils.getNodeFromTree(input)));
     });
diff --git a/test/rule-matches/data-table-matches.js b/test/rule-matches/data-table-matches.js
index ab1e92523f..24e0fff16e 100644
--- a/test/rule-matches/data-table-matches.js
+++ b/test/rule-matches/data-table-matches.js
@@ -1,9 +1,9 @@
 describe('data-table-matches', function () {
   'use strict';
 
-  var fixture = document.getElementById('fixture');
-  var fixtureSetup = axe.testUtils.fixtureSetup;
-  var rule;
+  const fixture = document.getElementById('fixture');
+  const fixtureSetup = axe.testUtils.fixtureSetup;
+  let rule;
 
   beforeEach(function () {
     rule = axe.utils.getRule('th-has-data-cells');
@@ -25,7 +25,7 @@ describe('data-table-matches', function () {
         '</table>'
     );
 
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'table')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'table')[0];
     assert.isFalse(rule.matches(vNode.actualNode, vNode));
   });
 
@@ -37,7 +37,7 @@ describe('data-table-matches', function () {
         '</table>'
     );
 
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'table')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'table')[0];
     assert.isFalse(rule.matches(vNode.actualNode, vNode));
   });
 
@@ -50,7 +50,7 @@ describe('data-table-matches', function () {
         '</table>'
     );
 
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'table')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'table')[0];
     assert.isTrue(rule.matches(vNode.actualNode, vNode));
   });
 });
diff --git a/test/rule-matches/duplicate-id-active-matches.js b/test/rule-matches/duplicate-id-active-matches.js
index 60bb45d3c6..f34db28c61 100644
--- a/test/rule-matches/duplicate-id-active-matches.js
+++ b/test/rule-matches/duplicate-id-active-matches.js
@@ -1,9 +1,9 @@
 describe('duplicate-id-active matches', function () {
   'use strict';
 
-  var fixture = document.getElementById('fixture');
-  var fixtureSetup = axe.testUtils.fixtureSetup;
-  var rule;
+  const fixture = document.getElementById('fixture');
+  const fixtureSetup = axe.testUtils.fixtureSetup;
+  let rule;
 
   beforeEach(function () {
     rule = axe.utils.getRule('duplicate-id-active');
@@ -19,31 +19,31 @@ describe('duplicate-id-active matches', function () {
 
   it('returns false if the ID is of an inactive non-referenced element', function () {
     fixtureSetup('<div id="foo"></div>');
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'div[id=foo]')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'div[id=foo]')[0];
     assert.isFalse(rule.matches(vNode.actualNode, vNode));
   });
 
   it('returns false if the ID is of an inactive non-referenced element with a duplicate', function () {
     fixtureSetup('<div id="foo"></div><span id="foo"></span>');
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'span[id=foo]')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'span[id=foo]')[0];
     assert.isFalse(rule.matches(vNode.actualNode, vNode));
   });
 
   it('returns true if the ID is of an active non-referenced element', function () {
     fixtureSetup('<button id="foo"></button>');
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'button[id=foo]')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'button[id=foo]')[0];
     assert.isTrue(rule.matches(vNode.actualNode, vNode));
   });
 
   it('returns true if the ID is a duplicate of an active non-referenced element', function () {
     fixtureSetup('<div id="foo"></div>' + '<button id="foo"></button>');
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'div[id=foo]')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'div[id=foo]')[0];
     assert.isTrue(rule.matches(vNode.actualNode, vNode));
   });
 
   it('returns false if the ID is of an inactive ARIA referenced element', function () {
     fixtureSetup('<div id="foo"></div>' + '<div aria-labelledby="foo"></div>');
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'div[id=foo]')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'div[id=foo]')[0];
     assert.isFalse(rule.matches(vNode.actualNode, vNode));
   });
 
@@ -53,7 +53,7 @@ describe('duplicate-id-active matches', function () {
         '<div aria-labelledby="foo"></div>' +
         '<span id="foo"></span>'
     );
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'span[id=foo]')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'span[id=foo]')[0];
     assert.isFalse(rule.matches(vNode.actualNode, vNode));
   });
 
@@ -61,7 +61,7 @@ describe('duplicate-id-active matches', function () {
     fixtureSetup(
       '<button id="foo"></button>' + '<div aria-labelledby="foo"></div>'
     );
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'button[id=foo]')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'button[id=foo]')[0];
     assert.isFalse(rule.matches(vNode.actualNode, vNode));
   });
 
@@ -71,7 +71,7 @@ describe('duplicate-id-active matches', function () {
         '<div aria-labelledby="foo"></div>' +
         '<span id="foo"></span>'
     );
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'span[id=foo]')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'span[id=foo]')[0];
     assert.isFalse(rule.matches(vNode.actualNode, vNode));
   });
 });
diff --git a/test/rule-matches/duplicate-id-aria-matches.js b/test/rule-matches/duplicate-id-aria-matches.js
index 2ebd3a0714..4ddf03f740 100644
--- a/test/rule-matches/duplicate-id-aria-matches.js
+++ b/test/rule-matches/duplicate-id-aria-matches.js
@@ -1,9 +1,9 @@
 describe('duplicate-id-aria matches', function () {
   'use strict';
 
-  var fixture = document.getElementById('fixture');
-  var fixtureSetup = axe.testUtils.fixtureSetup;
-  var rule;
+  const fixture = document.getElementById('fixture');
+  const fixtureSetup = axe.testUtils.fixtureSetup;
+  let rule;
 
   beforeEach(function () {
     rule = axe.utils.getRule('duplicate-id-aria');
@@ -19,31 +19,31 @@ describe('duplicate-id-aria matches', function () {
 
   it('returns false if the ID is of an inactive non-referenced element', function () {
     fixtureSetup('<div id="foo"></div>');
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'div[id=foo]')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'div[id=foo]')[0];
     assert.isFalse(rule.matches(vNode.actualNode, vNode));
   });
 
   it('returns false if the ID is of an inactive non-referenced element with a duplicate', function () {
     fixtureSetup('<div id="foo"></div><span id="foo"></span>');
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'span[id=foo]')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'span[id=foo]')[0];
     assert.isFalse(rule.matches(vNode.actualNode, vNode));
   });
 
   it('returns false if the ID is of an active non-referenced element', function () {
     fixtureSetup('<button id="foo"></button>');
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'button[id=foo]')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'button[id=foo]')[0];
     assert.isFalse(rule.matches(vNode.actualNode, vNode));
   });
 
   it('returns false if the ID is a duplicate of an active non-referenced element', function () {
     fixtureSetup('<div id="foo"></div>' + '<button id="foo"></button>');
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'div[id=foo]')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'div[id=foo]')[0];
     assert.isFalse(rule.matches(vNode.actualNode, vNode));
   });
 
   it('returns true if the ID is of an inactive ARIA referenced element', function () {
     fixtureSetup('<div id="foo"></div>' + '<div aria-labelledby="foo"></div>');
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'div[id=foo]')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'div[id=foo]')[0];
     assert.isTrue(rule.matches(vNode.actualNode, vNode));
   });
 
@@ -53,7 +53,7 @@ describe('duplicate-id-aria matches', function () {
         '<div aria-labelledby="foo"></div>' +
         '<span id="foo"></span>'
     );
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'span[id=foo]')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'span[id=foo]')[0];
     assert.isTrue(rule.matches(vNode.actualNode, vNode));
   });
 
@@ -61,7 +61,7 @@ describe('duplicate-id-aria matches', function () {
     fixtureSetup(
       '<button id="foo"></button>' + '<div aria-labelledby="foo"></div>'
     );
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'button[id=foo]')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'button[id=foo]')[0];
     assert.isTrue(rule.matches(vNode.actualNode, vNode));
   });
 
@@ -71,7 +71,7 @@ describe('duplicate-id-aria matches', function () {
         '<div aria-labelledby="foo"></div>' +
         '<span id="foo"></span>'
     );
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'span[id=foo]')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'span[id=foo]')[0];
     assert.isTrue(rule.matches(vNode.actualNode, vNode));
   });
 });
diff --git a/test/rule-matches/duplicate-id-misc-matches.js b/test/rule-matches/duplicate-id-misc-matches.js
index 77f2331b22..d44c94059b 100644
--- a/test/rule-matches/duplicate-id-misc-matches.js
+++ b/test/rule-matches/duplicate-id-misc-matches.js
@@ -1,9 +1,9 @@
 describe('duplicate-id-misc matches', function () {
   'use strict';
 
-  var fixture = document.getElementById('fixture');
-  var fixtureSetup = axe.testUtils.fixtureSetup;
-  var rule;
+  const fixture = document.getElementById('fixture');
+  const fixtureSetup = axe.testUtils.fixtureSetup;
+  let rule;
 
   beforeEach(function () {
     rule = axe.utils.getRule('duplicate-id');
@@ -19,31 +19,31 @@ describe('duplicate-id-misc matches', function () {
 
   it('returns true if the ID is of an inactive non-referenced element', function () {
     fixtureSetup('<div id="foo"></div>');
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'div[id=foo]')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'div[id=foo]')[0];
     assert.isTrue(rule.matches(vNode.actualNode, vNode));
   });
 
   it('returns true if the ID is of an inactive non-referenced element with a duplicate', function () {
     fixtureSetup('<div id="foo"></div><span id="foo"></span>');
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'span[id=foo]')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'span[id=foo]')[0];
     assert.isTrue(rule.matches(vNode.actualNode, vNode));
   });
 
   it('returns false if the ID is of an active non-referenced element', function () {
     fixtureSetup('<button id="foo"></button>');
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'button[id=foo]')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'button[id=foo]')[0];
     assert.isFalse(rule.matches(vNode.actualNode, vNode));
   });
 
   it('returns false if the ID is a duplicate of an active non-referenced element', function () {
     fixtureSetup('<div id="foo"></div>' + '<button id="foo"></button>');
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'div[id=foo]')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'div[id=foo]')[0];
     assert.isFalse(rule.matches(vNode.actualNode, vNode));
   });
 
   it('returns false if the ID is of an inactive ARIA referenced element', function () {
     fixtureSetup('<div id="foo"></div>' + '<div aria-labelledby="foo"></div>');
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'div[id=foo]')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'div[id=foo]')[0];
     assert.isFalse(rule.matches(vNode.actualNode, vNode));
   });
 
@@ -53,7 +53,7 @@ describe('duplicate-id-misc matches', function () {
         '<div aria-labelledby="foo"></div>' +
         '<span id="foo"></span>'
     );
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'span[id=foo]')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'span[id=foo]')[0];
     assert.isFalse(rule.matches(vNode.actualNode, vNode));
   });
 
@@ -61,7 +61,7 @@ describe('duplicate-id-misc matches', function () {
     fixtureSetup(
       '<button id="foo"></button>' + '<div aria-labelledby="foo"></div>'
     );
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'button[id=foo]')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'button[id=foo]')[0];
     assert.isFalse(rule.matches(vNode.actualNode, vNode));
   });
 
@@ -71,7 +71,7 @@ describe('duplicate-id-misc matches', function () {
         '<div aria-labelledby="foo"></div>' +
         '<span id="foo"></span>'
     );
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'span[id=foo]')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'span[id=foo]')[0];
     assert.isFalse(rule.matches(vNode.actualNode, vNode));
   });
 });
diff --git a/test/rule-matches/frame-focusable-content-matches.js b/test/rule-matches/frame-focusable-content-matches.js
index 8adc9ef5b7..996397bc2b 100644
--- a/test/rule-matches/frame-focusable-content-matches.js
+++ b/test/rule-matches/frame-focusable-content-matches.js
@@ -1,13 +1,13 @@
 describe('frame-focusable-content-matches', function () {
   'use strict';
-  var rule;
+  let rule;
 
   beforeEach(function () {
     rule = axe.utils.getRule('frame-focusable-content');
   });
 
   it('returns false for the top-level context', function () {
-    var result = rule.matches(null, null, {
+    const result = rule.matches(null, null, {
       initiator: true,
       focusable: false,
       size: {
@@ -19,7 +19,7 @@ describe('frame-focusable-content-matches', function () {
   });
 
   it('returns false for focusable iframes', function () {
-    var result = rule.matches(null, null, {
+    const result = rule.matches(null, null, {
       initiator: false,
       focusable: true,
       size: {
@@ -31,7 +31,7 @@ describe('frame-focusable-content-matches', function () {
   });
 
   it('returns false for non-focusable iframes that are too small (1x1)', function () {
-    var result = rule.matches(null, null, {
+    const result = rule.matches(null, null, {
       initiator: false,
       focusable: false,
       size: {
@@ -43,7 +43,7 @@ describe('frame-focusable-content-matches', function () {
   });
 
   it('returns false for non-focusable iframes that are too small (0x0)', function () {
-    var result = rule.matches(null, null, {
+    const result = rule.matches(null, null, {
       initiator: false,
       focusable: false,
       size: {
@@ -55,7 +55,7 @@ describe('frame-focusable-content-matches', function () {
   });
 
   it('returns true for non-focusable iframes', function () {
-    var result = rule.matches(null, null, {
+    const result = rule.matches(null, null, {
       initiator: false,
       focusable: false,
       size: {
diff --git a/test/rule-matches/frame-title-has-text-matches.js b/test/rule-matches/frame-title-has-text-matches.js
index cb9bbe42fc..c72859888a 100644
--- a/test/rule-matches/frame-title-has-text-matches.js
+++ b/test/rule-matches/frame-title-has-text-matches.js
@@ -1,8 +1,8 @@
 describe('layout-table-matches', function () {
   'use strict';
 
-  var fixture = document.getElementById('fixture');
-  var rule;
+  const fixture = document.getElementById('fixture');
+  let rule;
 
   beforeEach(function () {
     rule = axe.utils.getRule('frame-title-unique');
@@ -14,19 +14,19 @@ describe('layout-table-matches', function () {
 
   it('should return true if title attribute has text', function () {
     fixture.innerHTML = '<iframe title="hello"></iframe>';
-    var node = fixture.firstChild;
+    const node = fixture.firstChild;
     assert.isTrue(rule.matches(node));
   });
 
   it('should return false if title attribute is empty', function () {
     fixture.innerHTML = '<iframe title=""></iframe>';
-    var node = fixture.firstChild;
+    const node = fixture.firstChild;
     assert.isFalse(rule.matches(node));
   });
 
   it('should return false if title attribute contains only whitespace', function () {
     fixture.innerHTML = '<iframe title="    "></iframe>';
-    var node = fixture.firstChild;
+    const node = fixture.firstChild;
     assert.isFalse(rule.matches(node));
   });
 });
diff --git a/test/rule-matches/has-implicit-chromium-role-matches.js b/test/rule-matches/has-implicit-chromium-role-matches.js
index 55c54807c0..448cb2070d 100644
--- a/test/rule-matches/has-implicit-chromium-role-matches.js
+++ b/test/rule-matches/has-implicit-chromium-role-matches.js
@@ -1,9 +1,9 @@
 describe('has-implicit-chromium-role-matches', function () {
   'use strict';
 
-  var rule;
-  var fixture = document.getElementById('fixture');
-  var queryFixture = axe.testUtils.queryFixture;
+  let rule;
+  const fixture = document.getElementById('fixture');
+  const queryFixture = axe.testUtils.queryFixture;
 
   beforeEach(function () {
     rule = axe.utils.getRule('presentation-role-conflict');
@@ -18,22 +18,22 @@ describe('has-implicit-chromium-role-matches', function () {
   });
 
   it('matches elements with an implicit role', function () {
-    var vNode = queryFixture('<main id="target"></main>');
+    const vNode = queryFixture('<main id="target"></main>');
     assert.isTrue(rule.matches(null, vNode));
   });
 
   it('does not match elements with no implicit role', function () {
-    var vNode = queryFixture('<div id="target"></div>');
+    const vNode = queryFixture('<div id="target"></div>');
     assert.isFalse(rule.matches(null, vNode));
   });
 
   it('matches elements with an implicit role in chromium', function () {
-    var vNode = queryFixture('<svg id="target"></svg>');
+    const vNode = queryFixture('<svg id="target"></svg>');
     assert.isTrue(rule.matches(null, vNode));
   });
 
   it('does not match elements with no implicit role even if they are focusable and have an explicit role', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<div id="target" role="none" tabindex="1"></div>'
     );
     assert.isFalse(rule.matches(null, vNode));
diff --git a/test/rule-matches/heading-matches.js b/test/rule-matches/heading-matches.js
index 4939f16b9f..59f8250540 100644
--- a/test/rule-matches/heading-matches.js
+++ b/test/rule-matches/heading-matches.js
@@ -1,8 +1,8 @@
 describe('heading-matches', function () {
   'use strict';
-  var queryFixture = axe.testUtils.queryFixture;
-  var fixtureSetup = axe.testUtils.fixtureSetup;
-  var rule;
+  const queryFixture = axe.testUtils.queryFixture;
+  const fixtureSetup = axe.testUtils.fixtureSetup;
+  let rule;
 
   beforeEach(function () {
     rule = axe.utils.getRule('empty-heading');
@@ -13,39 +13,41 @@ describe('heading-matches', function () {
   });
 
   it('should return false on elements that are not headings', function () {
-    var vNode = fixtureSetup('<div></div>');
+    const vNode = fixtureSetup('<div></div>');
     assert.isFalse(rule.matches(null, vNode));
   });
 
   it('should return true on elements with role="heading"', function () {
-    var vNode = queryFixture('<div role="heading" id="target"></div>');
+    const vNode = queryFixture('<div role="heading" id="target"></div>');
     assert.isTrue(rule.matches(null, vNode));
   });
 
   it('should return true on regular headings without roles', function () {
-    for (var i = 1; i <= 6; i++) {
-      var vNode = queryFixture('<h' + i + ' id="target"></h' + i + '>');
+    for (let i = 1; i <= 6; i++) {
+      const vNode = queryFixture('<h' + i + ' id="target"></h' + i + '>');
       assert.isTrue(rule.matches(null, vNode));
     }
   });
 
   it('should return false on headings with their role changes', function () {
-    var vNode = queryFixture('<h1 role="banner" id="target"></h1>');
+    const vNode = queryFixture('<h1 role="banner" id="target"></h1>');
     assert.isFalse(rule.matches(null, vNode));
   });
 
   it('should return true on headings with their role changes to an invalid role', function () {
-    var vNode = queryFixture('<h1 role="bruce" id="target"></h1>');
+    const vNode = queryFixture('<h1 role="bruce" id="target"></h1>');
     assert.isTrue(rule.matches(null, vNode));
   });
 
   it('should return true on headings with their role changes to an abstract role', function () {
-    var vNode = queryFixture('<h1 role="widget" id="target"></h1>');
+    const vNode = queryFixture('<h1 role="widget" id="target"></h1>');
     assert.isTrue(rule.matches(null, vNode));
   });
 
   it('should return true on headings with explicit role="none" and an empty aria-label to account for presentation conflict resolution', function () {
-    var vNode = queryFixture('<h1 aria-label="" role="none" id="target"></h1>');
+    const vNode = queryFixture(
+      '<h1 aria-label="" role="none" id="target"></h1>'
+    );
     assert.isTrue(rule.matches(null, vNode));
   });
 });
diff --git a/test/rule-matches/html-namespace-matches.js b/test/rule-matches/html-namespace-matches.js
index 48ff0a2667..c6582e7ee7 100644
--- a/test/rule-matches/html-namespace-matches.js
+++ b/test/rule-matches/html-namespace-matches.js
@@ -1,8 +1,8 @@
 describe('html-namespace-matches', function () {
   'use strict';
-  var rule;
-  var fixture;
-  var axeFixtureSetup;
+  let rule;
+  let fixture;
+  let axeFixtureSetup;
 
   beforeEach(function () {
     fixture = document.getElementById('fixture');
@@ -16,22 +16,22 @@ describe('html-namespace-matches', function () {
 
   it('returns true when passed an HTML element', function () {
     axeFixtureSetup('<h1>Hello world</h1>');
-    var node = fixture.querySelector('h1');
-    var virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
+    const node = fixture.querySelector('h1');
+    const virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
     assert.isTrue(rule.matches(node, virtualNode));
   });
 
   it('returns true when passed a custom HTML element', function () {
     axeFixtureSetup('<xx-heading>Hello world</xx-heading>');
-    var node = fixture.querySelector('xx-heading');
-    var virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
+    const node = fixture.querySelector('xx-heading');
+    const virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
     assert.isTrue(rule.matches(node, virtualNode));
   });
 
   it('returns false when passed an SVG element', function () {
     axeFixtureSetup('<svg><title>Pretty picture</title></svg>');
-    var node = fixture.querySelector('svg');
-    var virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
+    const node = fixture.querySelector('svg');
+    const virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
     assert.isFalse(rule.matches(node, virtualNode));
   });
 
@@ -39,14 +39,14 @@ describe('html-namespace-matches', function () {
     axeFixtureSetup(
       '<svg><circle><title>Pretty picture</title></circle></svg>'
     );
-    var node = fixture.querySelector('circle');
-    var virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
+    const node = fixture.querySelector('circle');
+    const virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
     assert.isFalse(rule.matches(node, virtualNode));
   });
 
   describe('Serial Virtual Node', function () {
     it('returns true when passed an HTML element', function () {
-      var serialNode = new axe.SerialVirtualNode({
+      const serialNode = new axe.SerialVirtualNode({
         nodeName: 'h1'
       });
       serialNode.parent = null;
@@ -55,7 +55,7 @@ describe('html-namespace-matches', function () {
     });
 
     it('returns true when passed a custom HTML element', function () {
-      var serialNode = new axe.SerialVirtualNode({
+      const serialNode = new axe.SerialVirtualNode({
         nodeName: 'xx-heading'
       });
       serialNode.parent = null;
@@ -64,10 +64,10 @@ describe('html-namespace-matches', function () {
     });
 
     it('returns false when passed an SVG circle element', function () {
-      var serialNode = new axe.SerialVirtualNode({
+      const serialNode = new axe.SerialVirtualNode({
         nodeName: 'circle'
       });
-      var parent = new axe.SerialVirtualNode({
+      const parent = new axe.SerialVirtualNode({
         nodeName: 'svg'
       });
       serialNode.parent = parent;
diff --git a/test/rule-matches/html-xml-lang-mismatch.js b/test/rule-matches/html-xml-lang-mismatch.js
index b710aef5ca..cbac5a1fd8 100644
--- a/test/rule-matches/html-xml-lang-mismatch.js
+++ b/test/rule-matches/html-xml-lang-mismatch.js
@@ -3,9 +3,9 @@ describe('xml-lang-mismatch-matches', function () {
 
   // nested this on a per rule basis, for future-proofing writing tests for multiple rules using the same matches
   describe('for rule: html-xml-lang-mismatch', function () {
-    var rule;
-    var dom;
-    var fixture = document.getElementById('fixture');
+    let rule;
+    let dom;
+    const fixture = document.getElementById('fixture');
 
     beforeEach(function () {
       rule = axe.utils.getRule('html-xml-lang-mismatch');
@@ -17,33 +17,33 @@ describe('xml-lang-mismatch-matches', function () {
     });
 
     it('is a function', function () {
-      var actual = rule.matches;
+      const actual = rule.matches;
       assert.isFunction(actual);
     });
 
     it('returns false if the element does not contain lang or xml:lang attribute', function () {
-      var actual = rule.matches(dom);
+      const actual = rule.matches(dom);
       assert.isFalse(actual);
     });
 
     it('returns false if the element contains either/ only one of the lang or xml:lang attribute', function () {
       dom.setAttribute('lang', 'nl');
-      var actual = rule.matches(dom);
+      const actual = rule.matches(dom);
       assert.isFalse(actual);
     });
 
     it('returns true if the element contains both lang and xml:lang attribute', function () {
       dom.setAttribute('lang', 'en');
       dom.setAttribute('xml:lang', 'nl');
-      var actual = rule.matches(dom);
+      const actual = rule.matches(dom);
       assert.isTrue(actual);
     });
 
     it('returns false for element of type that is not HTML', function () {
-      var node = document.createElement('svg');
+      const node = document.createElement('svg');
       node.setAttribute('lang', '');
       node.setAttribute('xml:lang', 'nl');
-      var actual = rule.matches(node);
+      const actual = rule.matches(node);
       assert.isFalse(actual);
     });
   });
diff --git a/test/rule-matches/identical-links-same-purpose-matches.js b/test/rule-matches/identical-links-same-purpose-matches.js
index 9aa044bd08..7e130d8c88 100644
--- a/test/rule-matches/identical-links-same-purpose-matches.js
+++ b/test/rule-matches/identical-links-same-purpose-matches.js
@@ -1,9 +1,9 @@
 describe('identical-links-same-purpose-matches tests', function () {
   'use strict';
 
-  var fixture = document.getElementById('fixture');
-  var queryFixture = axe.testUtils.queryFixture;
-  var rule = axe.utils.getRule('identical-links-same-purpose');
+  const fixture = document.getElementById('fixture');
+  const queryFixture = axe.testUtils.queryFixture;
+  const rule = axe.utils.getRule('identical-links-same-purpose');
 
   afterEach(function () {
     fixture.innerHTML = '';
@@ -11,79 +11,81 @@ describe('identical-links-same-purpose-matches tests', function () {
   });
 
   it('returns false when native link without accessible name', function () {
-    var vNode = queryFixture('<a id="target" href=""></a>');
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const vNode = queryFixture('<a id="target" href=""></a>');
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isFalse(actual);
   });
 
   it('returns false for ARIA link without accessible name', function () {
-    var vNode = queryFixture('<span role="link" id="target"></span>');
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const vNode = queryFixture('<span role="link" id="target"></span>');
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isFalse(actual);
   });
 
   it('returns false for native link with a role !== link', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<a id="target" href="#" role="button">Go to Checkout</a>'
     );
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isFalse(actual);
   });
 
   it('returns false when `area` has no parent `map` element', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<area id="target" role="link" href="" shape="circle" coords="130,136,60" aria-label="MDN" />'
     );
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isFalse(actual);
   });
 
   it('returns false when `area` has parent `map` that is not referred by `img[usemap]`', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<map name="iam-not-referred">' +
         '<area id="target" role="link" href="" shape="circle" coords="130,136,60" aria-label="MDN" />' +
         '</map>'
     );
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isFalse(actual);
   });
 
   it('returns true when native link without href', function () {
-    var vNode = queryFixture('<a id="target">Book Now</a>');
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const vNode = queryFixture('<a id="target">Book Now</a>');
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isTrue(actual);
   });
 
   it('returns true when ARIA link without href', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<button id="target" role="link">Book Now</button>'
     );
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isTrue(actual);
   });
 
   it('returns true when native link has an accessible name', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<a id="target" href="https://developer.mozilla.org/" aria-label="Go to MDN website"></a>'
     );
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isTrue(actual);
   });
 
   it('returns true for ARIA link has an accessible name', function () {
-    var vNode = queryFixture('<span role="link" id="target">Book Tour</span>');
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const vNode = queryFixture(
+      '<span role="link" id="target">Book Tour</span>'
+    );
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isTrue(actual);
   });
 
   it('returns true when `area` has parent `map` that is referred by `img`', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<map name="iam-referred">' +
         '<area id="target" role="link" href="" shape="circle" coords="130,136,60" aria-label="MDN" />' +
         '</map>' +
         '<img usemap="#iam-referred" alt="MDN infographic" />'
     );
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isTrue(actual);
   });
 });
diff --git a/test/rule-matches/inserted-into-focus-order-matches.js b/test/rule-matches/inserted-into-focus-order-matches.js
index f9a56f3ed2..ff7ec134f8 100644
--- a/test/rule-matches/inserted-into-focus-order-matches.js
+++ b/test/rule-matches/inserted-into-focus-order-matches.js
@@ -1,9 +1,9 @@
 describe('inserted-into-focus-order-matches', function () {
   'use strict';
 
-  var fixture = document.getElementById('fixture');
-  var flatTreeSetup = axe.testUtils.flatTreeSetup;
-  var rule;
+  const fixture = document.getElementById('fixture');
+  const flatTreeSetup = axe.testUtils.flatTreeSetup;
+  let rule;
 
   beforeEach(function () {
     rule = axe.utils.getRule('focus-order-semantics');
@@ -16,35 +16,35 @@ describe('inserted-into-focus-order-matches', function () {
   it('should return true for a non-focusable element with tabindex > -1', function () {
     fixture.innerHTML = '<div tabindex="0"></div>';
     flatTreeSetup(fixture);
-    var node = fixture.firstChild;
+    const node = fixture.firstChild;
     assert.isTrue(rule.matches(node));
   });
 
   it('should return false for a non-focusable element with tabindex == -1', function () {
     fixture.innerHTML = '<div tabindex="-1"></div>';
     flatTreeSetup(fixture);
-    var node = fixture.firstChild;
+    const node = fixture.firstChild;
     assert.isFalse(rule.matches(node));
   });
 
   it('should return false for a native focusable element with tabindex > 0', function () {
     fixture.innerHTML = '<button tabindex="0"></button>';
     flatTreeSetup(fixture);
-    var node = fixture.firstChild;
+    const node = fixture.firstChild;
     assert.isFalse(rule.matches(node));
   });
 
   it('should return false for a native focusable element with no tabindex', function () {
     fixture.innerHTML = '<a href="#"></a>';
     flatTreeSetup(fixture);
-    var node = fixture.firstChild;
+    const node = fixture.firstChild;
     assert.isFalse(rule.matches(node));
   });
 
   it('should return false for non-numeric tabindex value', function () {
     fixture.innerHTML = '<div tabindex="abc"></div>';
     flatTreeSetup(fixture);
-    var node = fixture.firstChild;
+    const node = fixture.firstChild;
     assert.isFalse(rule.matches(node));
   });
 });
diff --git a/test/rule-matches/is-initiator-matches.js b/test/rule-matches/is-initiator-matches.js
index 8007f1f56a..91199ed245 100644
--- a/test/rule-matches/is-initiator-matches.js
+++ b/test/rule-matches/is-initiator-matches.js
@@ -1,14 +1,14 @@
 describe('is-initiator-matches', function () {
   'use strict';
 
-  var rule;
+  let rule;
 
   beforeEach(function () {
     rule = axe.utils.getRule('html-has-lang');
   });
 
   afterEach(function () {
-    var fixture = document.getElementById('fixture');
+    const fixture = document.getElementById('fixture');
     fixture.innerHTML = '';
   });
 
diff --git a/test/rule-matches/is-visible-matches.js b/test/rule-matches/is-visible-matches.js
index 847b796c25..b860986843 100644
--- a/test/rule-matches/is-visible-matches.js
+++ b/test/rule-matches/is-visible-matches.js
@@ -1,12 +1,12 @@
 describe('is-visible-matches', function () {
   'use strict';
 
-  var isVisibleMatches =
+  let isVisibleMatches =
     axe._thisWillBeDeletedDoNotUse.base.metadataFunctionMap[
       'is-visible-matches'
     ];
-  var fixture = document.getElementById('fixture');
-  var fixtureSetup = axe.testUtils.fixtureSetup;
+  let fixture = document.getElementById('fixture');
+  let fixtureSetup = axe.testUtils.fixtureSetup;
 
   it('returns true for visible elements', function () {
     fixtureSetup('<p id="target">Hello world</p>');
diff --git a/test/rule-matches/label-content-name-mismatch-matches.js b/test/rule-matches/label-content-name-mismatch-matches.js
index b47d2847d1..7252a98e83 100644
--- a/test/rule-matches/label-content-name-mismatch-matches.js
+++ b/test/rule-matches/label-content-name-mismatch-matches.js
@@ -1,9 +1,9 @@
 describe('label-content-name-mismatch-matches tests', function () {
   'use strict';
 
-  var fixture = document.getElementById('fixture');
-  var queryFixture = axe.testUtils.queryFixture;
-  var rule = axe.utils.getRule('label-content-name-mismatch');
+  const fixture = document.getElementById('fixture');
+  const queryFixture = axe.testUtils.queryFixture;
+  const rule = axe.utils.getRule('label-content-name-mismatch');
 
   afterEach(function () {
     fixture.innerHTML = '';
@@ -11,145 +11,145 @@ describe('label-content-name-mismatch-matches tests', function () {
   });
 
   it('returns false if given element has no role', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<div id="target" aria-label="what color is the sky?"></div>'
     );
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isFalse(actual);
   });
 
   it('returns false if element role is not supported with name from contents', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<div aria-label="choose your age" id="target" role="progressbar" aria-valuenow="20" aria-valuemin="0" aria-valuemax="100">20 %</div>'
     );
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isFalse(actual);
   });
 
   it('returns false if implicit element role is overridden to a role that does not support name from contents', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<div id="labelForStatusMsg">Status message</div>' +
         '<button id="target" role="status" aria-labelledby="labelForStatusMsg">Your changes were automatically saved.</button>'
     );
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isFalse(actual);
   });
 
   it('returns false if element does not have accessible name attributes (`aria-label` or `aria-labelledby`)', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<button id="target" name="link">Until the very end.</button>'
     );
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isFalse(actual);
   });
 
   it('returns false if element has empty accessible name via `aria-label`', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<button id="target" name="link" aria-label="">Until the very end.</button>'
     );
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isFalse(actual);
   });
 
   it('returns true if element has accessible name via `aria-label`', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<button id="target" name="link" aria-label="Until">Until the very end.</button>'
     );
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isTrue(actual);
   });
 
   it('returns true if element has accessible name via `aria-labelledby`', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<div role="button" id="target" aria-labelledby="foo">some content</div>' +
         '<div id="foo">Foo text</div>'
     );
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isTrue(actual);
   });
 
   it('returns false if element has empty accessible name (`aria-labelledby`)', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<div role="button" id="target" aria-labelledby="foo">some content</div>' +
         '<div id="foo"></div>'
     );
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isFalse(actual);
   });
 
   it('returns false if element has empty accessible name (`aria-labelledby`) because idref does not exist', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<div role="button" id="target" aria-labelledby="doesNotExist">some content</div>' +
         '<div id="idExists">Right Label</div>'
     );
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isFalse(actual);
   });
 
   it('returns true if element has accessible name (`aria-labelledby`) - multiple refs', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<div role="button" id="target" aria-labelledby="bar baz foo">some content</div>' +
         '<div id="foo">Foo</div>' +
         '<div id="bar">Bar</div>' +
         '<div id="baz">Baz</div>'
     );
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isTrue(actual);
   });
 
   it('returns false for non-widget role', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<a role="contentinfo" id="target" aria-label="some content">Content Information</a>'
     );
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isFalse(actual);
   });
 
   it('returns false for non-widget role that does support name from content', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<div id="target" role="tooltip" aria-label="OK">Next</div>'
     );
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isFalse(actual);
   });
 
   it('returns false for empty text content', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<button id="target" aria-label="close"></button>'
     );
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isFalse(actual);
   });
 
   it('returns false for non text content', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<button id="target" aria-label="close"><i class="fa fa-icon-close"></i></button>'
     );
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isFalse(actual);
   });
 
   it('returns false for hidden (non visible) text content', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<button id="target" aria-label="close"><span style="display:none">I am hidden</span></button>'
     );
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isFalse(actual);
   });
 
   it('returns true when visible text is combination of alphanumeric and emoji characters', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<button id="target" aria-label="I would like a burger">I would like a 🍔 </button>'
     );
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isTrue(actual);
   });
 
   it('returns true when visible text is combination of alphanumeric and punctuation characters', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<button id="target" aria-label="next page">next page &gt;</button>'
     );
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isTrue(actual);
   });
 });
diff --git a/test/rule-matches/label-matches.js b/test/rule-matches/label-matches.js
index 8dbdc304db..4e4058920f 100644
--- a/test/rule-matches/label-matches.js
+++ b/test/rule-matches/label-matches.js
@@ -1,9 +1,9 @@
 describe('label-matches', function () {
   'use strict';
 
-  var fixture = document.getElementById('fixture');
-  var queryFixture = axe.testUtils.queryFixture;
-  var rule;
+  const fixture = document.getElementById('fixture');
+  const queryFixture = axe.testUtils.queryFixture;
+  let rule;
 
   beforeEach(function () {
     fixture.innerHTML = '';
@@ -11,25 +11,25 @@ describe('label-matches', function () {
   });
 
   it('returns true for non-input elements', function () {
-    var vNode = queryFixture('<textarea id="target"></textarea>');
+    const vNode = queryFixture('<textarea id="target"></textarea>');
     assert.isTrue(rule.matches(null, vNode));
   });
 
   it('returns true for input elements without type', function () {
-    var vNode = queryFixture('<input id="target" />');
+    const vNode = queryFixture('<input id="target" />');
 
     assert.isTrue(rule.matches(null, vNode));
   });
 
   it('returns false for input buttons', function () {
     ['button', 'submit', 'image', 'reset'].forEach(function (type) {
-      var vNode = queryFixture('<input id="target" type="' + type + '" />');
+      const vNode = queryFixture('<input id="target" type="' + type + '" />');
       assert.isFalse(rule.matches(null, vNode));
     });
   });
 
   it('returns false for input elements type=hidden', function () {
-    var vNode = queryFixture('<input id="target" type="hidden" />');
+    const vNode = queryFixture('<input id="target" type="hidden" />');
 
     assert.isFalse(rule.matches(null, vNode));
   });
@@ -37,7 +37,7 @@ describe('label-matches', function () {
   it('returns true for other input types', function () {
     ['text', 'password', 'url', 'range', 'date', 'checkbox', 'radio'].forEach(
       function (type) {
-        var vNode = queryFixture('<input id="target" type="' + type + '" />');
+        const vNode = queryFixture('<input id="target" type="' + type + '" />');
         assert.isTrue(rule.matches(null, vNode));
       }
     );
diff --git a/test/rule-matches/landmark-has-body-context.js b/test/rule-matches/landmark-has-body-context.js
index 124ba3dc9e..3afa72e0b7 100644
--- a/test/rule-matches/landmark-has-body-context.js
+++ b/test/rule-matches/landmark-has-body-context.js
@@ -1,8 +1,8 @@
 describe('landmark-has-body-context', function () {
   'use strict';
-  var fixtureSetup = axe.testUtils.fixtureSetup;
-  var rule;
-  var shadowSupport = axe.testUtils.shadowSupport.v1;
+  const fixtureSetup = axe.testUtils.fixtureSetup;
+  let rule;
+  const shadowSupport = axe.testUtils.shadowSupport.v1;
 
   beforeEach(function () {
     rule = axe.utils.getRule('landmark-banner-is-top-level');
@@ -11,21 +11,21 @@ describe('landmark-has-body-context', function () {
   it('returns true for elements with a role', function () {
     fixtureSetup('<main><footer role="contentinfo"></footer></main>');
 
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'footer')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'footer')[0];
     assert.isTrue(rule.matches(vNode.actualNode, vNode));
   });
 
   it('returns true for elements not contained in a landmark', function () {
     fixtureSetup('<div><footer role="contentinfo"></footer></div>');
 
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'footer')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'footer')[0];
     assert.isTrue(rule.matches(vNode.actualNode, vNode));
   });
 
   it('returns false for elements contained in a landmark', function () {
     fixtureSetup('<main><footer></footer></main>');
 
-    var vNode = axe.utils.querySelectorAll(axe._tree[0], 'footer')[0];
+    const vNode = axe.utils.querySelectorAll(axe._tree[0], 'footer')[0];
     assert.isFalse(rule.matches(vNode.actualNode, vNode));
   });
 
@@ -35,12 +35,12 @@ describe('landmark-has-body-context', function () {
       // Safari has a bug in 12.0 that throws an error when calling
       // attachShadow on <main>
       // @see https://bugs.webkit.org/show_bug.cgi?id=197726
-      var article = document.createElement('article');
-      var shadow = article.attachShadow({ mode: 'open' });
+      const article = document.createElement('article');
+      const shadow = article.attachShadow({ mode: 'open' });
       shadow.innerHTML = '<footer></footer>';
 
       fixtureSetup(article);
-      var vNode = axe.utils.querySelectorAll(axe._tree[0], 'footer')[0];
+      const vNode = axe.utils.querySelectorAll(axe._tree[0], 'footer')[0];
       assert.isFalse(rule.matches(vNode.actualNode, vNode));
     }
   );
diff --git a/test/rule-matches/landmark-unique-matches.js b/test/rule-matches/landmark-unique-matches.js
index 518763d953..cb3cef7bde 100644
--- a/test/rule-matches/landmark-unique-matches.js
+++ b/test/rule-matches/landmark-unique-matches.js
@@ -1,13 +1,13 @@
 describe('landmark-unique-matches', function () {
   'use strict';
-  var rule;
-  var fixture;
-  var axeFixtureSetup;
-  var shadowSupport = axe.testUtils.shadowSupport.v1;
-  var sectioningContentElements = ['article', 'aside', 'nav', 'section'];
-  var excludedDescendantsForHeadersFooters =
+  let rule;
+  let fixture;
+  let axeFixtureSetup;
+  const shadowSupport = axe.testUtils.shadowSupport.v1;
+  const sectioningContentElements = ['article', 'aside', 'nav', 'section'];
+  const excludedDescendantsForHeadersFooters =
     sectioningContentElements.concat('main');
-  var headerFooterElements = ['header', 'footer'];
+  const headerFooterElements = ['header', 'footer'];
 
   beforeEach(function () {
     fixture = document.getElementById('fixture');
@@ -17,30 +17,30 @@ describe('landmark-unique-matches', function () {
 
   it('should not match because not a landmark', function () {
     axeFixtureSetup('<h1>some heading</h1>');
-    var node = fixture.querySelector('h1');
-    var virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
+    const node = fixture.querySelector('h1');
+    const virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
     assert.isFalse(rule.matches(node, virtualNode));
   });
 
   it('should pass because is a landmark', function () {
     axeFixtureSetup('<div role="banner">some banner</div>');
-    var node = fixture.querySelector('div');
+    const node = fixture.querySelector('div');
     fixture.appendChild(node);
-    var virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
+    const virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
     assert.isTrue(rule.matches(node, virtualNode));
   });
 
   it('should not match because landmark is hidden', function () {
     axeFixtureSetup('<div role="banner">some banner</div>');
-    var node = fixture.querySelector('div');
+    const node = fixture.querySelector('div');
     node.style.display = 'none';
     fixture.appendChild(node);
-    var virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
+    const virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
     assert.isFalse(rule.matches(node, virtualNode));
   });
 
   describe('form and section elements must have accessible names to be matched', function () {
-    var sectionFormElements = ['section', 'form'];
+    const sectionFormElements = ['section', 'form'];
 
     sectionFormElements.forEach(function (elementType) {
       it(
@@ -55,8 +55,8 @@ describe('landmark-unique-matches', function () {
               elementType +
               '>'
           );
-          var node = fixture.querySelector(elementType);
-          var virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
+          const node = fixture.querySelector(elementType);
+          const virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
           assert.isTrue(rule.matches(node, virtualNode));
         }
       );
@@ -73,8 +73,8 @@ describe('landmark-unique-matches', function () {
               elementType +
               '>'
           );
-          var node = fixture.querySelector(elementType);
-          var virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
+          const node = fixture.querySelector(elementType);
+          const virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
           assert.isFalse(rule.matches(node, virtualNode));
         }
       );
@@ -101,8 +101,8 @@ describe('landmark-unique-matches', function () {
                 exclusionType +
                 '>'
             );
-            var node = fixture.querySelector(elementType);
-            var virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
+            const node = fixture.querySelector(elementType);
+            const virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
             assert.isFalse(rule.matches(node, virtualNode));
           }
         );
@@ -116,8 +116,8 @@ describe('landmark-unique-matches', function () {
           axeFixtureSetup(
             '<' + elementType + '>an element</' + elementType + '>'
           );
-          var node = fixture.querySelector(elementType);
-          var virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
+          const node = fixture.querySelector(elementType);
+          const virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
           assert.isTrue(rule.matches(node, virtualNode));
         }
       );
@@ -138,8 +138,8 @@ describe('landmark-unique-matches', function () {
               exclusionType +
               '>'
           );
-          var node = fixture.querySelector('aside[data-test]');
-          var virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
+          const node = fixture.querySelector('aside[data-test]');
+          const virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
           assert.isFalse(rule.matches(node, virtualNode));
         }
       );
@@ -154,8 +154,8 @@ describe('landmark-unique-matches', function () {
               exclusionType +
               '>'
           );
-          var node = fixture.querySelector('aside[data-test]');
-          var virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
+          const node = fixture.querySelector('aside[data-test]');
+          const virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
           assert.isTrue(rule.matches(node, virtualNode));
         }
       );
@@ -163,26 +163,26 @@ describe('landmark-unique-matches', function () {
 
     it('should match because aside is not scoped to a sectioning content element', function () {
       axeFixtureSetup('<aside>an element</aside>');
-      var node = fixture.querySelector('aside');
-      var virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
+      const node = fixture.querySelector('aside');
+      const virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
       assert.isTrue(rule.matches(node, virtualNode));
     });
   });
 
   if (shadowSupport) {
     it('return true for landmarks contained within shadow dom', function () {
-      var container = document.createElement('div');
-      var shadow = container.attachShadow({ mode: 'open' });
+      const container = document.createElement('div');
+      const shadow = container.attachShadow({ mode: 'open' });
       shadow.innerHTML = '<footer></footer>';
 
       axeFixtureSetup(container);
-      var vNode = axe.utils.querySelectorAll(axe._tree[0], 'footer')[0];
+      const vNode = axe.utils.querySelectorAll(axe._tree[0], 'footer')[0];
       assert.isTrue(rule.matches(vNode.actualNode, vNode));
     });
 
     describe('header/footers should only match when not inside the excluded descendants within shadow dom', function () {
-      var container;
-      var shadow;
+      let container;
+      let shadow;
 
       beforeEach(function () {
         container = document.createElement('div');
@@ -210,7 +210,7 @@ describe('landmark-unique-matches', function () {
                 '>';
 
               axeFixtureSetup(container);
-              var virtualNode = axe.utils.querySelectorAll(
+              const virtualNode = axe.utils.querySelectorAll(
                 axe._tree[0],
                 elementType
               )[0];
@@ -227,7 +227,7 @@ describe('landmark-unique-matches', function () {
             shadow.innerHTML =
               '<' + elementType + '>an element</' + elementType + '>';
             axeFixtureSetup(container);
-            var virtualNode = axe.utils.querySelectorAll(
+            const virtualNode = axe.utils.querySelectorAll(
               axe._tree[0],
               elementType
             )[0];
@@ -238,8 +238,8 @@ describe('landmark-unique-matches', function () {
     });
 
     describe('aside should match inside shadow dom unless it is both within sectioning content and has no accessible name', function () {
-      var container;
-      var shadow;
+      let container;
+      let shadow;
 
       beforeEach(function () {
         container = document.createElement('div');
@@ -260,7 +260,7 @@ describe('landmark-unique-matches', function () {
               '>';
 
             axeFixtureSetup(container);
-            var virtualNode = axe.utils.querySelectorAll(
+            const virtualNode = axe.utils.querySelectorAll(
               axe._tree[0],
               'aside[data-test]'
             )[0];
@@ -278,7 +278,7 @@ describe('landmark-unique-matches', function () {
               exclusionType +
               '>';
             axeFixtureSetup(container);
-            var virtualNode = axe.utils.querySelectorAll(
+            const virtualNode = axe.utils.querySelectorAll(
               axe._tree[0],
               'aside[data-test]'
             )[0];
@@ -290,7 +290,10 @@ describe('landmark-unique-matches', function () {
       it('should match because aside is not scoped to a sectioning content element', function () {
         shadow.innerHTML = '<aside>an element</aside>';
         axeFixtureSetup(container);
-        var virtualNode = axe.utils.querySelectorAll(axe._tree[0], 'aside')[0];
+        const virtualNode = axe.utils.querySelectorAll(
+          axe._tree[0],
+          'aside'
+        )[0];
         assert.isTrue(rule.matches(virtualNode.actualNode, virtualNode));
       });
     });
diff --git a/test/rule-matches/layout-table-matches.js b/test/rule-matches/layout-table-matches.js
index cae2b1ff73..c86cb5ac37 100644
--- a/test/rule-matches/layout-table-matches.js
+++ b/test/rule-matches/layout-table-matches.js
@@ -1,9 +1,9 @@
 describe('layout-table-matches', function () {
   'use strict';
 
-  var fixture = document.getElementById('fixture');
-  var flatTreeSetup = axe.testUtils.flatTreeSetup;
-  var rule;
+  const fixture = document.getElementById('fixture');
+  const flatTreeSetup = axe.testUtils.flatTreeSetup;
+  let rule;
 
   beforeEach(function () {
     axe.configure({
@@ -26,7 +26,7 @@ describe('layout-table-matches', function () {
   it('should return false for data table', function () {
     fixture.innerHTML = '<table><caption>Hello></caption></table>';
     flatTreeSetup(fixture);
-    var node = fixture.firstChild;
+    const node = fixture.firstChild;
 
     assert.isFalse(rule.matches(node));
   });
@@ -34,7 +34,7 @@ describe('layout-table-matches', function () {
   it('should return false if the table is focusable', function () {
     fixture.innerHTML = '<table tabindex="0"></table>';
     flatTreeSetup(fixture);
-    var node = fixture.firstChild;
+    const node = fixture.firstChild;
 
     assert.isFalse(rule.matches(node));
   });
@@ -42,7 +42,7 @@ describe('layout-table-matches', function () {
   it('should return true if table has role=presentation', function () {
     fixture.innerHTML = '<table role="presentation"></table>';
     flatTreeSetup(fixture);
-    var node = fixture.firstChild;
+    const node = fixture.firstChild;
 
     assert.isTrue(rule.matches(node));
   });
@@ -50,7 +50,7 @@ describe('layout-table-matches', function () {
   it('should return true if table has role=none', function () {
     fixture.innerHTML = '<table role="none"></table>';
     flatTreeSetup(fixture);
-    var node = fixture.firstChild;
+    const node = fixture.firstChild;
 
     assert.isTrue(rule.matches(node));
   });
diff --git a/test/rule-matches/nested-interactive-matches.js b/test/rule-matches/nested-interactive-matches.js
index c4bebe5148..9c76d7082c 100644
--- a/test/rule-matches/nested-interactive-matches.js
+++ b/test/rule-matches/nested-interactive-matches.js
@@ -1,7 +1,7 @@
 describe('nested-interactive-matches', function () {
-  var fixture = document.querySelector('#fixture');
-  var queryFixture = axe.testUtils.queryFixture;
-  var rule;
+  const fixture = document.querySelector('#fixture');
+  const queryFixture = axe.testUtils.queryFixture;
+  let rule;
 
   beforeEach(function () {
     rule = axe.utils.getRule('nested-interactive');
@@ -12,22 +12,22 @@ describe('nested-interactive-matches', function () {
   });
 
   it('should match if element has children presentational', function () {
-    var vNode = queryFixture('<button id="target"></button>');
+    const vNode = queryFixture('<button id="target"></button>');
     assert.isTrue(rule.matches(null, vNode));
   });
 
   it('should match if aria element has children presentational', function () {
-    var vNode = queryFixture('<div role="button" id="target"></div>');
+    const vNode = queryFixture('<div role="button" id="target"></div>');
     assert.isTrue(rule.matches(null, vNode));
   });
 
   it('should not match if element does not have children presentational', function () {
-    var vNode = queryFixture('<a href="foo.html" id="target"></a>');
+    const vNode = queryFixture('<a href="foo.html" id="target"></a>');
     assert.isFalse(rule.matches(null, vNode));
   });
 
   it('should not match if element has no role', function () {
-    var vNode = queryFixture('<span id="target"></span>');
+    const vNode = queryFixture('<span id="target"></span>');
     assert.isFalse(rule.matches(null, vNode));
   });
 });
diff --git a/test/rule-matches/no-autoplay-audio-matches.js b/test/rule-matches/no-autoplay-audio-matches.js
index 1769e3e897..037582cbf9 100644
--- a/test/rule-matches/no-autoplay-audio-matches.js
+++ b/test/rule-matches/no-autoplay-audio-matches.js
@@ -1,10 +1,10 @@
 describe('no-autoplay-audio-matches', function () {
   'use strict';
 
-  var fixture = document.getElementById('fixture');
-  var queryFixture = axe.testUtils.queryFixture;
-  var preloadOptions = { preload: { assets: ['media'] } };
-  var rule;
+  const fixture = document.getElementById('fixture');
+  const queryFixture = axe.testUtils.queryFixture;
+  const preloadOptions = { preload: { assets: ['media'] } };
+  let rule;
 
   beforeEach(function () {
     rule = axe.utils.getRule('no-autoplay-audio');
@@ -15,37 +15,37 @@ describe('no-autoplay-audio-matches', function () {
   });
 
   it('returns false for <audio> element that has no src attribute', function (done) {
-    var vNode = queryFixture('<audio id="target"></audio>');
+    const vNode = queryFixture('<audio id="target"></audio>');
     axe.utils.preload(preloadOptions).then(function () {
-      var actual = rule.matches(vNode.actualNode);
+      const actual = rule.matches(vNode.actualNode);
       assert.isFalse(actual);
       done();
     });
   });
 
   it('returns false for <video> element that is paused', function (done) {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<video id="target" autoplay="true" paused="true">' +
         '<source src="/test/assets/video.webm" type="video/webm" />' +
         '<source src="/test/assets/video.mp4" type="video/mp4" />' +
         '</video>'
     );
     axe.utils.preload(preloadOptions).then(function () {
-      var actual = rule.matches(vNode.actualNode);
+      const actual = rule.matches(vNode.actualNode);
       assert.isFalse(actual);
       done();
     });
   });
 
   it('returns false for <video> element that is muted', function (done) {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<video id="target" autoplay="true" muted="true">' +
         '<source src="/test/assets/video.webm" type="video/webm" />' +
         '<source src="/test/assets/video.mp4" type="video/mp4" />' +
         '</video>'
     );
     axe.utils.preload(preloadOptions).then(function () {
-      var actual = rule.matches(vNode.actualNode);
+      const actual = rule.matches(vNode.actualNode);
       assert.isFalse(actual);
       done();
     });
diff --git a/test/rule-matches/no-empty-role-matches.js b/test/rule-matches/no-empty-role-matches.js
index c632540eb0..b50f5ba711 100644
--- a/test/rule-matches/no-empty-role-matches.js
+++ b/test/rule-matches/no-empty-role-matches.js
@@ -1,9 +1,9 @@
 describe('no-role-empty-matches', function () {
   'use strict';
 
-  var fixture = document.getElementById('fixture');
-  var queryFixture = axe.testUtils.queryFixture;
-  var rule;
+  const fixture = document.getElementById('fixture');
+  const queryFixture = axe.testUtils.queryFixture;
+  let rule;
 
   beforeEach(function () {
     rule = axe.utils.getRule('aria-roles');
@@ -14,48 +14,50 @@ describe('no-role-empty-matches', function () {
   });
 
   it('returns false when element does not have `role` attribute', function () {
-    var vNode = queryFixture('<div id="target">Some Content</div>');
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const vNode = queryFixture('<div id="target">Some Content</div>');
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isFalse(actual);
   });
 
   it('returns false when element has role attribute has no value', function () {
-    var vNode = queryFixture('<div role id="target">Some Content</div>');
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const vNode = queryFixture('<div role id="target">Some Content</div>');
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isFalse(actual);
   });
 
   it('returns false when element has empty role attribute', function () {
-    var vNode = queryFixture('<div role="" id="target">Some Content</div>');
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const vNode = queryFixture('<div role="" id="target">Some Content</div>');
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isFalse(actual);
   });
 
   it('returns false when element has role attribute consisting of only whitespace', function () {
-    var vNode = queryFixture('<div role=" " id="target">Some Content</div>');
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const vNode = queryFixture('<div role=" " id="target">Some Content</div>');
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isFalse(actual);
   });
 
   it('returns true when element has role attribute', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<div role="button" id="target">Some Content</div>'
     );
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isTrue(actual);
   });
 
   it('returns true when element has multiple roles', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<div role="button link" id="target">Some Content</div>'
     );
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isTrue(actual);
   });
 
   it('returns true when element has invalid role', function () {
-    var vNode = queryFixture('<div role="xyz" id="target">Some Content</div>');
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const vNode = queryFixture(
+      '<div role="xyz" id="target">Some Content</div>'
+    );
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isTrue(actual);
   });
 });
diff --git a/test/rule-matches/no-explicit-name-required-matches.js b/test/rule-matches/no-explicit-name-required-matches.js
index 2cbde6d07d..11e23cb884 100644
--- a/test/rule-matches/no-explicit-name-required-matches.js
+++ b/test/rule-matches/no-explicit-name-required-matches.js
@@ -1,9 +1,9 @@
 describe('no-explicit-name-matches', function () {
   'use strict';
 
-  var fixture = document.getElementById('fixture');
-  var queryFixture = axe.testUtils.queryFixture;
-  var rule;
+  const fixture = document.getElementById('fixture');
+  const queryFixture = axe.testUtils.queryFixture;
+  let rule;
 
   beforeEach(function () {
     rule = axe.utils.getRule('button-name');
@@ -14,51 +14,51 @@ describe('no-explicit-name-matches', function () {
   });
 
   it('returns true when element does not have `role` attribute', function () {
-    var vNode = queryFixture('<button id="target"></button>');
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const vNode = queryFixture('<button id="target"></button>');
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isTrue(actual);
   });
 
   it('returns true when element has an explicit role of presentation', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<button id="target" role="presentation"></button>'
     );
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isTrue(actual);
   });
 
   it('returns true when element has an explicit role of none', function () {
-    var vNode = queryFixture('<button id="target" role="none"></button>');
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const vNode = queryFixture('<button id="target" role="none"></button>');
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isTrue(actual);
   });
 
   it('returns true when element has an invalid explicit role', function () {
-    var vNode = queryFixture('<button id="target" role="foo"></button>');
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const vNode = queryFixture('<button id="target" role="foo"></button>');
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isTrue(actual);
   });
 
   it('returns true when element has an explicit role that requires an accessible name', function () {
-    var vNode = queryFixture('<button id="target" role="button"></button>');
-    var actual = rule.matches(vNode.actualNode, vNode);
+    const vNode = queryFixture('<button id="target" role="button"></button>');
+    const actual = rule.matches(vNode.actualNode, vNode);
     assert.isTrue(actual);
   });
 
   describe('with a role that does not require an accessible name', function () {
     it('returns true when element is focusable', function () {
-      var vNode = queryFixture(
+      const vNode = queryFixture(
         '<button id="target" role="separator"></button>'
       );
-      var actual = rule.matches(vNode.actualNode, vNode);
+      const actual = rule.matches(vNode.actualNode, vNode);
       assert.isTrue(actual);
     });
 
     it('returns false when element is not focusable', function () {
-      var vNode = queryFixture(
+      const vNode = queryFixture(
         '<button id="target" role="separator" disabled></button>'
       );
-      var actual = rule.matches(vNode.actualNode, vNode);
+      const actual = rule.matches(vNode.actualNode, vNode);
       assert.isFalse(actual);
     });
   });
diff --git a/test/rule-matches/no-naming-method-matches.js b/test/rule-matches/no-naming-method-matches.js
index c92213817e..da042c5ba1 100644
--- a/test/rule-matches/no-naming-method-matches.js
+++ b/test/rule-matches/no-naming-method-matches.js
@@ -1,95 +1,95 @@
 describe('no-naming-method-matches', function () {
   'use strict';
 
-  var fixture = document.getElementById('fixture');
-  var queryFixture = axe.testUtils.queryFixture;
-  var rule = axe.utils.getRule('aria-toggle-field-name');
+  const fixture = document.getElementById('fixture');
+  const queryFixture = axe.testUtils.queryFixture;
+  const rule = axe.utils.getRule('aria-toggle-field-name');
 
   afterEach(function () {
     fixture.innerHTML = '';
   });
 
   it('returns false for node `a[href]`', function () {
-    var vNode = queryFixture('<a href="# role="checkbox" id="target"></a>');
-    var actual = rule.matches(null, vNode);
+    const vNode = queryFixture('<a href="# role="checkbox" id="target"></a>');
+    const actual = rule.matches(null, vNode);
     assert.isFalse(actual);
   });
 
   it('returns false for node `map area[href]`', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<map><area id="target" href="#" role="checkbox"></map>'
     );
-    var actual = rule.matches(null, vNode);
+    const actual = rule.matches(null, vNode);
     assert.isFalse(actual);
   });
 
   it('returns false when node is either INPUT, SELECT or TEXTAREA', function () {
     ['input', 'select', 'textarea'].forEach(function (node) {
-      var vNode = queryFixture(
+      const vNode = queryFixture(
         '<' + node + ' role="menuitemcheckbox" id="target"><' + node + '>'
       );
-      var actual = rule.matches(null, vNode);
+      const actual = rule.matches(null, vNode);
       assert.isFalse(actual);
     });
   });
 
   it('returns false when node is IMG', function () {
-    var vNode = queryFixture('<img id="target" role="menuitemradio">');
-    var actual = rule.matches(null, vNode);
+    const vNode = queryFixture('<img id="target" role="menuitemradio">');
+    const actual = rule.matches(null, vNode);
     assert.isFalse(actual);
   });
 
   it('returns false when node is not SVG', function () {
-    var vNode = queryFixture('<svg id="target"></svg>');
-    var actual = rule.matches(null, vNode);
+    const vNode = queryFixture('<svg id="target"></svg>');
+    const actual = rule.matches(null, vNode);
     assert.isFalse(actual);
   });
 
   it('returns false when node is BUTTON', function () {
-    var vNode = queryFixture('<button id="target"></button>');
-    var actual = rule.matches(null, vNode);
+    const vNode = queryFixture('<button id="target"></button>');
+    const actual = rule.matches(null, vNode);
     assert.isFalse(actual);
   });
 
   it('returns false for INPUT of type `BUTTON`, `SUBMIT` or `RESET`', function () {
     ['button', 'submit', 'reset'].forEach(function (type) {
-      var vNode = queryFixture(
+      const vNode = queryFixture(
         '<input id="target" role="radio" type="' + type + '">'
       );
-      var actual = rule.matches(null, vNode);
+      const actual = rule.matches(null, vNode);
       assert.isFalse(actual);
     });
   });
 
   it('returns false when role=`combobox` has a child input', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<div id="target" role="combobox"><input type="text"/></div>'
     );
-    var actual = rule.matches(null, vNode);
+    const actual = rule.matches(null, vNode);
     assert.isFalse(actual);
   });
 
   it('returns false for the listbox popup of a role=`combobox`', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<div role="combobox" aria-controls="target"></div>' +
         '<div id="target" role="listbox"></div>'
     );
-    var actual = rule.matches(null, vNode);
+    const actual = rule.matches(null, vNode);
     assert.isFalse(actual);
   });
 
   it('returns true for the dialog popup of a role=`combobox`', function () {
-    var vNode = queryFixture(
+    const vNode = queryFixture(
       '<div role="combobox" aria-controls="target"></div>' +
         '<div id="target" role="dialog"></div>'
     );
-    var actual = rule.matches(null, vNode);
+    const actual = rule.matches(null, vNode);
     assert.isTrue(actual);
   });
 
   it('returns true for a div with role=`button`', function () {
-    var vNode = queryFixture('<div id="target" role="button"></div>');
-    var actual = rule.matches(null, vNode);
+    const vNode = queryFixture('<div id="target" role="button"></div>');
+    const actual = rule.matches(null, vNode);
     assert.isTrue(actual);
   });
 });
diff --git a/test/rule-matches/no-negative-tabindex.js b/test/rule-matches/no-negative-tabindex.js
index 0699edc39b..9e2998e6e8 100644
--- a/test/rule-matches/no-negative-tabindex.js
+++ b/test/rule-matches/no-negative-tabindex.js
@@ -1,41 +1,41 @@
 describe('no-negative-tabindex-matches', function () {
   'use strict';
 
-  var fixture = document.getElementById('fixture');
-  var queryFixture = axe.testUtils.queryFixture;
-  var rule = axe.utils.getRule('frame-title');
+  const fixture = document.getElementById('fixture');
+  const queryFixture = axe.testUtils.queryFixture;
+  const rule = axe.utils.getRule('frame-title');
 
   afterEach(function () {
     fixture.innerHTML = '';
   });
 
   it('returns true for nodes with no tabindex', function () {
-    var vNode = queryFixture('<div id="target"></div>');
-    var actual = rule.matches(null, vNode);
+    const vNode = queryFixture('<div id="target"></div>');
+    const actual = rule.matches(null, vNode);
     assert.isTrue(actual);
   });
 
   it('returns true for nodes with a zero tabindex', function () {
-    var vNode = queryFixture('<div id="target" tabindex="0"></div>');
-    var actual = rule.matches(null, vNode);
+    const vNode = queryFixture('<div id="target" tabindex="0"></div>');
+    const actual = rule.matches(null, vNode);
     assert.isTrue(actual);
   });
 
   it('returns true for nodes with a positive tabindex', function () {
-    var vNode = queryFixture('<div id="target" tabindex="4"></div>');
-    var actual = rule.matches(null, vNode);
+    const vNode = queryFixture('<div id="target" tabindex="4"></div>');
+    const actual = rule.matches(null, vNode);
     assert.isTrue(actual);
   });
 
   it('returns true for nodes with an invalid tabindex', function () {
-    var vNode = queryFixture('<div id="target" tabindex="foo"></div>');
-    var actual = rule.matches(null, vNode);
+    const vNode = queryFixture('<div id="target" tabindex="foo"></div>');
+    const actual = rule.matches(null, vNode);
     assert.isTrue(actual);
   });
 
   it('returns false for nodes with a negative tabindex', function () {
-    var vNode = queryFixture('<div id="target" tabindex="-10"></div>');
-    var actual = rule.matches(null, vNode);
+    const vNode = queryFixture('<div id="target" tabindex="-10"></div>');
+    const actual = rule.matches(null, vNode);
     assert.isFalse(actual);
   });
 });
diff --git a/test/rule-matches/p-as-heading-matches.js b/test/rule-matches/p-as-heading-matches.js
index e33a6fdbcf..1dad796b24 100644
--- a/test/rule-matches/p-as-heading-matches.js
+++ b/test/rule-matches/p-as-heading-matches.js
@@ -1,8 +1,8 @@
 describe('p-as-heading-matches', function () {
   'use strict';
 
-  var rule;
-  var fixture = document.getElementById('fixture');
+  let rule;
+  const fixture = document.getElementById('fixture');
 
   beforeEach(function () {
     rule = axe.utils.getRule('p-as-heading');
@@ -18,14 +18,14 @@ describe('p-as-heading-matches', function () {
 
   it('matches p elements', function () {
     fixture.innerHTML = '<p id="target">some text</p><p>some other text</p>';
-    var target = fixture.querySelector('#target');
+    const target = fixture.querySelector('#target');
 
     assert.isTrue(rule.matches(target));
   });
 
   it('ignores the last p element in a list of children', function () {
     fixture.innerHTML = '<p>some text</p><p id="target">some other text</p>';
-    var target = fixture.querySelector('#target');
+    const target = fixture.querySelector('#target');
 
     assert.isFalse(rule.matches(target));
   });
@@ -33,21 +33,21 @@ describe('p-as-heading-matches', function () {
   it('ignores p elements that contains punctuation marks', function () {
     fixture.innerHTML =
       '<p id="target">A text. Paragraph?</p><p>some other text</p>';
-    var target = fixture.querySelector('#target');
+    const target = fixture.querySelector('#target');
 
     assert.isFalse(rule.matches(target));
   });
 
   it('matches p elements with a single punctuation mark', function () {
     fixture.innerHTML = '<p id="target">A paragraph?</p><p>some other text</p>';
-    var target = fixture.querySelector('#target');
+    const target = fixture.querySelector('#target');
 
     assert.isTrue(rule.matches(target));
   });
 
   it('ignores p elements that have no text-like characters', function () {
     fixture.innerHTML = '<p id="target"> \n\t\r </p><p>some other text</p>';
-    var target = fixture.querySelector('#target');
+    const target = fixture.querySelector('#target');
 
     assert.isFalse(rule.matches(target));
   });
@@ -55,7 +55,7 @@ describe('p-as-heading-matches', function () {
   it('ignores siblings that are not p elements', function () {
     fixture.innerHTML =
       '<p id="target">some text</p><div></div><p>some other text</p>';
-    var target = fixture.querySelector('#target');
+    let target = fixture.querySelector('#target');
 
     assert.isTrue(rule.matches(target));
 
@@ -68,7 +68,7 @@ describe('p-as-heading-matches', function () {
   it('ignores empty p elements as siblings', function () {
     fixture.innerHTML =
       '<p id="target">some text</p><p> <!-- nothing here --><img src="" alt="" /></p>';
-    var target = fixture.querySelector('#target');
+    const target = fixture.querySelector('#target');
 
     assert.isFalse(rule.matches(target));
   });
diff --git a/test/rule-matches/scrollable-region-focusable-matches.js b/test/rule-matches/scrollable-region-focusable-matches.js
index 96ce6d32c5..01dfe17710 100644
--- a/test/rule-matches/scrollable-region-focusable-matches.js
+++ b/test/rule-matches/scrollable-region-focusable-matches.js
@@ -1,146 +1,146 @@
 describe('scrollable-region-focusable-matches', function () {
   'use strict';
 
-  var fixture = document.getElementById('fixture');
-  var queryFixture = axe.testUtils.queryFixture;
-  var shadowSupported = axe.testUtils.shadowSupport.v1;
-  var rule = axe.utils.getRule('scrollable-region-focusable');
+  const fixture = document.getElementById('fixture');
+  const queryFixture = axe.testUtils.queryFixture;
+  const shadowSupported = axe.testUtils.shadowSupport.v1;
+  const rule = axe.utils.getRule('scrollable-region-focusable');
 
   afterEach(function () {
     fixture.innerHTML = '';
   });
 
   it('returns false when element is not scrollable', function () {
-    var target = queryFixture(
+    const target = queryFixture(
       '<section id="target">This element is not scrollable</section>'
     );
-    var actual = rule.matches(target.actualNode, target);
+    const actual = rule.matches(target.actualNode, target);
     assert.isFalse(actual);
   });
 
   it('returns false when element has no visible children', function () {
-    var target = queryFixture(
+    const target = queryFixture(
       '<div id="target" style="height: 200px; width: 200px;">' +
         '<div style="display:none; height: 2000px; width: 100px;">' +
         '<p> Content </p>' +
         '</div>' +
         '</div>'
     );
-    var actual = rule.matches(target.actualNode, target);
+    const actual = rule.matches(target.actualNode, target);
     assert.isFalse(actual);
   });
 
   it('returns false when element does not overflow', function () {
-    var target = queryFixture(
+    const target = queryFixture(
       '<div id="target" style="height: 200px; width: 200px; overflow: auto;">' +
         '<div style="height: 10px; width: 100x;">Content</div>' +
         '</div>'
     );
-    var actual = rule.matches(target.actualNode, target);
+    const actual = rule.matches(target.actualNode, target);
     assert.isFalse(actual);
   });
 
   it('returns false when element is not scrollable (overflow=hidden)', function () {
-    var target = queryFixture(
+    const target = queryFixture(
       '<div id="target" style="height: 200px; width: 200px; overflow: hidden">' +
         '<div style="height: 2000px; width: 100px; background-color: pink;">' +
         '<p> Content </p>' +
         '</div>' +
         '</div>'
     );
-    var actual = rule.matches(target.actualNode, target);
+    const actual = rule.matches(target.actualNode, target);
     assert.isFalse(actual);
   });
 
   it('returns true when element is scrollable (overflow=auto)', function () {
-    var target = queryFixture(
+    const target = queryFixture(
       '<div id="target" style="height: 200px; width: 200px; overflow: auto">' +
         '<div style="height: 10px; width: 2000px; background-color: red;">' +
         '<p> Content </p>' +
         '</div>' +
         '</div>'
     );
-    var actual = rule.matches(target.actualNode, target);
+    const actual = rule.matches(target.actualNode, target);
     assert.isTrue(actual);
   });
 
   it('returns false when element overflow is visible', function () {
-    var target = queryFixture(
+    const target = queryFixture(
       '<p id="target" style="width: 12em; height: 2em; border: dotted; overflow: visible;">Sed ut perspiciatis unde omnis iste natus error sit voluptatem accusantium doloremque laudantium.</p>'
     );
-    var actual = rule.matches(target.actualNode, target);
+    const actual = rule.matches(target.actualNode, target);
     assert.isFalse(actual);
   });
 
   it('returns true when element overflow is scroll', function () {
-    var target = queryFixture(
+    const target = queryFixture(
       '<p id="target" style="width: 12em; height: 2em; border: dotted; overflow: scroll;">Sed ut perspiciatis unde omnis iste natus error sit voluptatem accusantium doloremque laudantium.</p>'
     );
-    var actual = rule.matches(target.actualNode, target);
+    const actual = rule.matches(target.actualNode, target);
     assert.isTrue(actual);
   });
 
   it('returns false when element overflow is scroll but has no content', function () {
-    var target = queryFixture(
+    const target = queryFixture(
       '<div id="target" style="width: 12em; height: 2em; border: dotted; overflow: scroll;"><div style="height: 15rem"></div></div>'
     );
-    var actual = rule.matches(target.actualNode, target);
+    const actual = rule.matches(target.actualNode, target);
     assert.isFalse(actual);
   });
 
   it('returns false when element has combobox ancestor', function () {
-    var target = queryFixture(
+    const target = queryFixture(
       '<div role="combobox"><ul id="target" role="listbox" style="width: 12em; height: 2em; border: dotted; overflow: scroll;"><li role="option" style="height: 15rem">Option</li></ul></div>'
     );
-    var actual = rule.matches(target.actualNode, target);
+    const actual = rule.matches(target.actualNode, target);
     assert.isFalse(actual);
   });
 
   it('returns false when element is owned by combobox', function () {
-    var target = queryFixture(
+    const target = queryFixture(
       '<input role="combobox" aria-owns="foo target"/><ul id="target" role="listbox" style="width: 12em; height: 2em; border: dotted; overflow: scroll;"><li role="option" style="height: 15rem">Option</li></ul>'
     );
-    var actual = rule.matches(target.actualNode, target);
+    const actual = rule.matches(target.actualNode, target);
     assert.isFalse(actual);
   });
 
   it('returns false when element is controlled by combobox', function () {
-    var target = queryFixture(
+    const target = queryFixture(
       '<input role="combobox" aria-controls="foo target"/><ul id="target" role="listbox" style="width: 12em; height: 2em; border: dotted; overflow: scroll;"><li role="option" style="height: 15rem">Option</li></ul>'
     );
-    var actual = rule.matches(target.actualNode, target);
+    const actual = rule.matches(target.actualNode, target);
     assert.isFalse(actual);
   });
 
   it('returns false for combobox with tree', function () {
-    var target = queryFixture(
+    const target = queryFixture(
       '<div role="combobox"><ul id="target" role="tree" style="width: 12em; height: 2em; border: dotted; overflow: scroll;"><li role="option" style="height: 15rem">Option</li></ul></div>'
     );
-    var actual = rule.matches(target.actualNode, target);
+    const actual = rule.matches(target.actualNode, target);
     assert.isFalse(actual);
   });
 
   it('returns false for combobox with grid', function () {
-    var target = queryFixture(
+    const target = queryFixture(
       '<div role="combobox"><ul id="target" role="grid" style="width: 12em; height: 2em; border: dotted; overflow: scroll;"><li role="option" style="height: 15rem">Option</li></ul></div>'
     );
-    var actual = rule.matches(target.actualNode, target);
+    const actual = rule.matches(target.actualNode, target);
     assert.isFalse(actual);
   });
 
   it('returns false for combobox with dialog', function () {
-    var target = queryFixture(
+    const target = queryFixture(
       '<div role="combobox"><ul id="target" role="dialog" style="width: 12em; height: 2em; border: dotted; overflow: scroll;"><li role="option" style="height: 15rem">Option</li></ul></div>'
     );
-    var actual = rule.matches(target.actualNode, target);
+    const actual = rule.matches(target.actualNode, target);
     assert.isFalse(actual);
   });
 
   it('returns true for combobox with non-valid role', function () {
-    var target = queryFixture(
+    const target = queryFixture(
       '<div role="combobox"><ul id="target" role="section" style="width: 12em; height: 2em; border: dotted; overflow: scroll;"><li role="option" style="height: 15rem">Option</li></ul></div>'
     );
-    var actual = rule.matches(target.actualNode, target);
+    const actual = rule.matches(target.actualNode, target);
     assert.isTrue(actual);
   });
 
@@ -158,28 +158,28 @@ describe('scrollable-region-focusable-matches', function () {
     it('returns false when shadowDOM element does not overflow', function () {
       fixture.innerHTML = '<div></div>';
 
-      var root = fixture.firstChild.attachShadow({ mode: 'open' });
-      var slotted = document.createElement('div');
+      const root = fixture.firstChild.attachShadow({ mode: 'open' });
+      const slotted = document.createElement('div');
       slotted.innerHTML =
         '<p id="target" style="width: 12em; height: 2em; border: dotted;">Sed.</p>';
       root.appendChild(slotted);
-      var tree = (axe._tree = axe.utils.getFlattenedTree(fixture.firstChild));
-      var target = axe.utils.querySelectorAll(tree, 'p')[0];
-      var actual = rule.matches(target.actualNode, target);
+      const tree = (axe._tree = axe.utils.getFlattenedTree(fixture.firstChild));
+      const target = axe.utils.querySelectorAll(tree, 'p')[0];
+      const actual = rule.matches(target.actualNode, target);
       assert.isFalse(actual);
     });
 
     it('returns true when shadowDOM element has overflow', function () {
       fixture.innerHTML = '<div></div>';
 
-      var root = fixture.firstChild.attachShadow({ mode: 'open' });
-      var slotted = document.createElement('div');
+      const root = fixture.firstChild.attachShadow({ mode: 'open' });
+      const slotted = document.createElement('div');
       slotted.innerHTML =
         '<p id="target" style="width: 12em; height: 2em; border: dotted; overflow: auto;">This is a repeated long sentence, This is a repeated long sentence, This is a repeated long sentence, This is a repeated long sentence, This is a repeated long sentence.</p>';
       root.appendChild(slotted);
-      var tree = (axe._tree = axe.utils.getFlattenedTree(fixture.firstChild));
-      var target = axe.utils.querySelectorAll(tree, 'p')[0];
-      var actual = rule.matches(target.actualNode, target);
+      const tree = (axe._tree = axe.utils.getFlattenedTree(fixture.firstChild));
+      const target = axe.utils.querySelectorAll(tree, 'p')[0];
+      const actual = rule.matches(target.actualNode, target);
       assert.isTrue(actual);
     });
   });
diff --git a/test/rule-matches/skip-link-matches.js b/test/rule-matches/skip-link-matches.js
index 5c0106ce80..752e243e17 100644
--- a/test/rule-matches/skip-link-matches.js
+++ b/test/rule-matches/skip-link-matches.js
@@ -1,8 +1,8 @@
 describe('skip-link-matches', function () {
   'use strict';
 
-  var rule, link;
-  var fixture = document.getElementById('fixture');
+  let rule, link;
+  const fixture = document.getElementById('fixture');
 
   beforeEach(function () {
     rule = axe.utils.getRule('skip-link');
diff --git a/test/rule-matches/svg-namespace-matches.js b/test/rule-matches/svg-namespace-matches.js
index 868efe088b..d72dea5b1f 100644
--- a/test/rule-matches/svg-namespace-matches.js
+++ b/test/rule-matches/svg-namespace-matches.js
@@ -1,8 +1,8 @@
 describe('svg-namespace-matches', function () {
   'use strict';
-  var rule;
-  var fixture;
-  var axeFixtureSetup;
+  let rule;
+  let fixture;
+  let axeFixtureSetup;
 
   beforeEach(function () {
     fixture = document.getElementById('fixture');
@@ -16,8 +16,8 @@ describe('svg-namespace-matches', function () {
 
   it('returns true when passed an SVG element', function () {
     axeFixtureSetup('<svg><title>Pretty picture</title></svg>');
-    var node = fixture.querySelector('svg');
-    var virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
+    const node = fixture.querySelector('svg');
+    const virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
     assert.isTrue(rule.matches(node, virtualNode));
   });
 
@@ -25,31 +25,31 @@ describe('svg-namespace-matches', function () {
     axeFixtureSetup(
       '<svg><circle><title>Pretty picture</title></circle></svg>'
     );
-    var node = fixture.querySelector('circle');
-    var virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
+    const node = fixture.querySelector('circle');
+    const virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
     assert.isTrue(rule.matches(node, virtualNode));
   });
 
   it('returns false when passed an HTML element', function () {
     axeFixtureSetup('<h1>Hello world</h1>');
-    var node = fixture.querySelector('h1');
-    var virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
+    const node = fixture.querySelector('h1');
+    const virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
     assert.isFalse(rule.matches(node, virtualNode));
   });
 
   it('returns false when passed a custom HTML element', function () {
     axeFixtureSetup('<xx-heading>Hello world</xx-heading>');
-    var node = fixture.querySelector('xx-heading');
-    var virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
+    const node = fixture.querySelector('xx-heading');
+    const virtualNode = axe.utils.getNodeFromTree(axe._tree[0], node);
     assert.isFalse(rule.matches(node, virtualNode));
   });
 
   describe('Serial Virtual Node', function () {
     it('should return true when passed an SVG element', function () {
-      var serialNode = new axe.SerialVirtualNode({
+      const serialNode = new axe.SerialVirtualNode({
         nodeName: 'svg'
       });
-      var child = new axe.SerialVirtualNode({
+      const child = new axe.SerialVirtualNode({
         nodeName: 'title',
         nodeValue: 'Pretty picture'
       });
@@ -60,10 +60,10 @@ describe('svg-namespace-matches', function () {
     });
 
     it('returns true when passed an SVG circle element', function () {
-      var serialNode = new axe.SerialVirtualNode({
+      const serialNode = new axe.SerialVirtualNode({
         nodeName: 'svg'
       });
-      var child = new axe.SerialVirtualNode({
+      const child = new axe.SerialVirtualNode({
         nodeName: 'circle'
       });
       child.parent = serialNode;
@@ -73,7 +73,7 @@ describe('svg-namespace-matches', function () {
     });
 
     it('returns false when passed an HTML element', function () {
-      var serialNode = new axe.SerialVirtualNode({
+      const serialNode = new axe.SerialVirtualNode({
         nodeName: 'h1',
         nodeValue: 'Hello world'
       });
@@ -82,10 +82,10 @@ describe('svg-namespace-matches', function () {
     });
 
     it('should return false when passed an svg element without a parent', function () {
-      var serialNode = new axe.SerialVirtualNode({
+      const serialNode = new axe.SerialVirtualNode({
         nodeName: 'circle'
       });
-      var parent = new axe.SerialVirtualNode({
+      const parent = new axe.SerialVirtualNode({
         nodeName: 'svg'
       });
       parent.children = [serialNode];