feat: Add rule, landmark-main-is-top-level (#462)

* init

* feat: add new rule, landmark-no-more-than-one-main

* test(landmark-at-least-one-main): updated integration tests for check

* feat(landmark-main-is-top-level): add rule ensuring each main landmark in a document is not within another landmark element

* refactor(landmark-main-is-top-level): change help messages

* feat(landmark-main-is-top-level): change a function used in check and update aria index file so application type is structure

* refactor(main-is-top-level): change pass/fail messages

* refactor(landmark-main-is-top-level): change description/help messages

* feat(main-is-top-level): update check for shadow dom features

* fix(main-is-top-level): update check to ignore form as a landmark

* fix: edit incorrect usage of getComposedParent

* test: add unit test to check if main landmark in shadow dom is top level

* style: remove spaces in attributes

* fix: update test so that checkSetup passes in correct argument

* test: add test to ensure correct number of violations nodes

* fix: revert 'application' type to landmark

* style: remove spaces in attributes

* fix: allow main landmark to be in form

doc/rule-descriptions.md

@@ -33,6 +33,7 @@
 | input-image-alt | Ensures <input type="image"> elements have alternate text | cat.text-alternatives, wcag2a, wcag111, section508, section508.22.a | true |
 | label-title-only | Ensures that every form element is not solely labeled using the title or aria-describedby attributes | cat.forms, best-practice | false |
 | label | Ensures every form element has a label | cat.forms, wcag2a, wcag332, wcag131, section508, section508.22.n | true |
+| landmark-main-is-top-level | The main landmark should not be contained in another landmark | best-practice | true |
 | layout-table | Ensures presentational <table> elements do not use <th>, <caption> elements or the summary attribute | cat.semantics, wcag2a, wcag131 | true |
 | link-in-text-block | Links can be distinguished without relying on color | cat.color, experimental, wcag2a, wcag141 | true |
 | link-name | Ensures links have discernible text | cat.name-role-value, wcag2a, wcag111, wcag412, wcag244, section508, section508.22.a | true |

lib/checks/keyboard/main-is-top-level.js

@@ -0,0 +1,13 @@
+var landmarks = axe.commons.aria.getRolesByType('landmark');
+var parent = axe.commons.dom.getComposedParent(node);
+while (parent){
+	var role = parent.getAttribute('role');
+	if (!role && (parent.tagName.toLowerCase() !== 'form')){
+		role = axe.commons.aria.implicitRole(parent);
+	}
+	if (role && landmarks.includes(role)){
+		return false;
+	}
+	parent = axe.commons.dom.getComposedParent(parent);
+}
+return true;

lib/checks/keyboard/main-is-top-level.json

@@ -0,0 +1,11 @@
+{
+  "id": "main-is-top-level",
+  "evaluate": "main-is-top-level.js",
+  "metadata": {
+    "impact": "moderate",
+    "messages": {
+      "pass": "The main landmark is at the top level.",
+      "fail": "The main landmark is contained in another landmark."
+    }
+  }
+}

lib/rules/landmark-main-is-top-level.json

@@ -0,0 +1,16 @@
+{
+  "id": "landmark-main-is-top-level",
+  "selector": "main,[role=main]",
+  "tags": [
+	"best-practice"
+  ],
+  "metadata": {
+    "description": "The main landmark should not be contained in another landmark",
+    "help": "Main landmark is not at top level"
+  },
+  "all": [],
+  "any": [
+    "main-is-top-level"
+  ],
+  "none": []
+}

test/checks/keyboard/main-is-top-level.js

@@ -0,0 +1,70 @@
+describe('main-is-top-level', function () {
+	'use strict';
+
+	var fixture = document.getElementById('fixture');
+
+	var shadowSupported = axe.testUtils.shadowSupport.v1;
+	var checkSetup = axe.testUtils.checkSetup;
+
+	afterEach(function () {
+		fixture.innerHTML = '';
+	});
+
+	it('should return false if main landmark is in another landmark', function () {
+		var mainLandmark = document.createElement('main');
+		var bannerDiv = document.createElement('div');
+		bannerDiv.setAttribute('role','banner');
+		bannerDiv.appendChild(mainLandmark);
+		fixture.appendChild(bannerDiv);
+		assert.isFalse(checks['main-is-top-level'].evaluate(mainLandmark));
+	});
+
+	it('should return false if div with role set to main is in another landmark', function () {
+		var mainDiv = document.createElement('div');
+		mainDiv.setAttribute('role','main');
+		var navDiv = document.createElement('div');
+		navDiv.setAttribute('role','navigation');
+		navDiv.appendChild(mainDiv);
+		fixture.appendChild(navDiv);
+		assert.isFalse(checks['main-is-top-level'].evaluate(mainDiv));
+	});
+
+	it('should return true if main landmark is not in another landmark', function () {
+		var mainLandmark = document.createElement('main');
+		var bannerDiv = document.createElement('div');
+		bannerDiv.setAttribute('role','banner');
+		fixture.appendChild(bannerDiv);
+		fixture.appendChild(mainLandmark);
+		assert.isTrue(checks['main-is-top-level'].evaluate(mainLandmark));
+	});
+
+	it('should return true if div with role set to main is not in another landmark', function () {
+		var mainDiv = document.createElement('div');
+		mainDiv.setAttribute('role','main');
+		var navDiv = document.createElement('div');
+		navDiv.setAttribute('role','navigation');
+		fixture.appendChild(navDiv);
+		fixture.appendChild(mainDiv);
+		assert.isTrue(checks['main-is-top-level'].evaluate(mainDiv));
+	});
+
+	it('should return true if main is in form landmark', function () {
+		var mainDiv = document.createElement('div');
+		mainDiv.setAttribute('role','main');
+		var formDiv = document.createElement('div');
+		formDiv.setAttribute('role','form');
+		fixture.appendChild(formDiv);
+		fixture.appendChild(mainDiv);
+		assert.isTrue(checks['main-is-top-level'].evaluate(mainDiv));
+	});
+
+
+	(shadowSupported ? it : xit)('should test if main in shadow DOM is top level', function () {
+		var div = document.createElement('div');
+		var shadow = div.attachShadow({ mode: 'open' });
+		shadow.innerHTML = '<main>Main content</main>';
+		var checkArgs = checkSetup(shadow.querySelector('main'));
+		assert.isTrue(checks['main-is-top-level'].evaluate.apply(null, checkArgs));
+	});
+
+});

test/integration/full/landmark-main-is-top-level/frames/level1-fail.html

@@ -0,0 +1,17 @@
+<!doctype html>
+<html id="violation2">
+<head>
+	<meta charset="utf8">
+	<script src="/axe.js"></script>
+</head>
+<body>
+	<p>This iframe should fail, too</p>
+	<div role="complementary">
+		<div role="main">
+			<p>This main landmark is in a complementary landmark</p>
+		</div>
+	</div>
+	<iframe id="frame2" src="level2.html"></iframe>
+	<iframe id="frame3" src="level2-a.html"></iframe>
+</body>
+</html>

test/integration/full/landmark-main-is-top-level/frames/level1.html

@@ -0,0 +1,29 @@
+<!doctype html>
+<html id="pass2">
+<head>
+	<meta charset="utf8">
+	<script src="/axe.js"></script>
+</head>
+<body>
+	<p>This iframe should pass, too</p>
+
+	<div role="banner">
+		<p>This div has role banner</p>
+	</div>
+	<div role="navigation">
+		<p>This div has role navigation</p>
+	</div>
+	<div role="main">
+		<p>This main content is not within another landmark</p>
+	</div>
+	<div role="complementary">
+		<p>This div has role complementary</p>
+	</div>
+	<div role="search">
+		<p>This div has role search</p>
+	</div>
+	<div role="form">
+		<p>This div has role form<p>
+	</div>
+</body>
+</html>

test/integration/full/landmark-main-is-top-level/frames/level2-a.html

@@ -0,0 +1,15 @@
+<!doctype html>
+<html id="violation4">
+<head>
+	<meta charset="utf8">
+	<script src="/axe.js"></script>
+</head>
+<body>
+	<p>This iframe is also a violation</p>
+	<div role="navigation">
+		<main>
+			<p>This main landmark is in a navigation landmark</p>
+		</main>
+	</div>
+</body>
+</html>

test/integration/full/landmark-main-is-top-level/frames/level2.html

@@ -0,0 +1,15 @@
+<!doctype html>
+<html id="violation3">
+<head>
+	<meta charset="utf8">
+	<script src="/axe.js"></script>
+</head>
+<body>
+	<p>This iframe is another violation<p>
+	<div role="search">
+		<main>
+			<p>This main landmark is in a search landmark</p>
+		</main>
+	</div>
+</body>
+</html>

test/integration/full/landmark-main-is-top-level/landmark-main-is-top-level-fail.html

@@ -0,0 +1,29 @@
+<!doctype html>
+<html lang="en" id="violation1">
+<head>
+	<title>landmark-main-is-top-level test</title>
+	<meta charset="utf8">
+	<link rel="stylesheet" type="text/css" href="/node_modules/mocha/mocha.css" />
+	<script src="/node_modules/mocha/mocha.js"></script>
+	<script src="/node_modules/chai/chai.js"></script>
+	<script src="/axe.js"></script>
+	<script>
+		mocha.setup({
+			timeout: 10000,
+			ui: 'bdd'
+		});
+		var assert = chai.assert;
+	</script>
+</head>
+<body>
+	<div role="navigation">
+		<div role="main">
+			<p>This is going to fail</p>
+		</div>
+	</div>
+	<iframe id="frame1" src="frames/level1-fail.html"></iframe>
+	<div id="mocha"></div>
+	<script src="landmark-main-is-top-level-fail.js"></script>
+	<script src="/test/integration/adapter.js"></script>
+</body>
+</html>

test/integration/full/landmark-main-is-top-level/landmark-main-is-top-level-fail.js

@@ -0,0 +1,42 @@
+
+describe('landmark-main-is-top-level test fail', function () {
+	'use strict';
+	var results;
+	before(function (done) {
+		window.addEventListener('load', function () {
+			axe.run({ runOnly: { type: 'rule', values: ['landmark-main-is-top-level'] } }, function (err, r) {
+				assert.isNull(err);
+				results = r;
+				done();
+			});
+		});
+	});
+
+	describe('violations', function () {
+		it('should find 1', function () {
+			assert.lengthOf(results.violations, 1);
+		});
+
+		it('should find 4 nodes', function () {
+			assert.lengthOf(results.violations[0].nodes, 4);
+		});
+	});
+
+	describe('passes', function () {
+		it('should find none', function () {
+			assert.lengthOf(results.passes, 0);
+		});
+
+	});
+
+
+	it('should find 0 inapplicable', function () {
+		assert.lengthOf(results.inapplicable, 0);
+	});
+
+	it('should find 0 incomplete', function () {
+		assert.lengthOf(results.incomplete, 0);
+	});
+
+});
+

test/integration/full/landmark-main-is-top-level/landmark-main-is-top-level-pass.html

@@ -0,0 +1,42 @@
+<!doctype html>
+<html lang="en" id="pass1">
+<head>
+	<title>landmark-main-is-top-level test</title>
+	<meta charset="utf8">
+	<link rel="stylesheet" type="text/css" href="/node_modules/mocha/mocha.css" />
+	<script src="/node_modules/mocha/mocha.js"></script>
+	<script src="/node_modules/chai/chai.js"></script>
+	<script src="/axe.js"></script>
+	<script>
+		mocha.setup({
+			timeout: 10000,
+			ui: 'bdd'
+		});
+		var assert = chai.assert;
+	</script>
+</head>
+<body>
+	<div role="banner">
+		<p>This div has role banner</p>
+	</div>
+	<div role="navigation">
+		<p>This div has role navigation</p>
+	</div>
+	<main>
+		<p>This main content is not within another landmark</p>
+	</main>
+	<div role="complementary">
+		<p>This div has role complementary</p>
+	</div>
+	<div role="search">
+		<p>This div has role search</p>
+	</div>
+	<div role="form">
+		<p>This div has role form<p>
+	</div>
+	<iframe id="frame1" src="frames/level1.html"></iframe>
+	<div id="mocha"></div>
+	<script src="landmark-main-is-top-level-pass.js"></script>
+	<script src="/test/integration/adapter.js"></script>
+</body>
+</html>

test/integration/full/landmark-main-is-top-level/landmark-main-is-top-level-pass.js

@@ -0,0 +1,36 @@
+
+describe('landmark-main-is-top-level test pass', function () {
+	'use strict';
+	var results;
+	before(function (done) {
+		window.addEventListener('load', function () {
+			axe.run({ runOnly: { type: 'rule', values: ['landmark-main-is-top-level'] } }, function (err, r) {
+				assert.isNull(err);
+				results = r;
+				done();
+			});
+		});
+	});
+
+	describe('violations', function () {
+		it('should find 0', function () {
+			assert.lengthOf(results.violations, 0);
+		});
+	});
+
+	describe('passes', function () {
+		it('should find 2', function () {
+			assert.lengthOf(results.passes[0].nodes, 2);
+		});
+	});
+
+	it('should find 0 inapplicable', function () {
+		assert.lengthOf(results.inapplicable, 0);
+	});
+
+	it('should find 0 incomplete', function () {
+		assert.lengthOf(results.incomplete, 0);
+	});
+
+});
+