events: deal with no argument case

PR-URL: #33611 Reviewed-By: Michaël Zasso <targos@protonmail.com> Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
nodejs · May 31, 2020 · 8ae28ff · 8ae28ff
1 parent 2935f72
commit 8ae28ff
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diff --git a/lib/internal/event_target.js b/lib/internal/event_target.js
@@ -15,6 +15,7 @@ const {
     ERR_INVALID_ARG_TYPE,
     ERR_EVENT_RECURSION,
     ERR_OUT_OF_RANGE,
+    ERR_MISSING_ARGS
   }
 } = require('internal/errors');
 
@@ -44,6 +45,9 @@ class Event {
 
 
   constructor(type, options) {
+    if (arguments.length === 0) {
+      throw new ERR_MISSING_ARGS('type');
+    }
     if (options != null && typeof options !== 'object')
       throw new ERR_INVALID_ARG_TYPE('options', 'object', options);
     const { cancelable, bubbles, composed } = { ...options };

diff --git a/test/parallel/test-eventtarget.js b/test/parallel/test-eventtarget.js
@@ -29,6 +29,7 @@ ok(EventTarget);
   strictEqual(ev.defaultPrevented, false);
   strictEqual(typeof ev.timeStamp, 'number');
 
+  // Compatibility properties with the DOM
   deepStrictEqual(ev.composedPath(), []);
   strictEqual(ev.returnValue, true);
   strictEqual(ev.bubbles, false);
@@ -40,7 +41,15 @@ ok(EventTarget);
   ev.preventDefault();
   strictEqual(ev.defaultPrevented, false);
 }
-
+{
+  // No argument behavior - throw TypeError
+  throws(() => {
+    new Event();
+  }, TypeError);
+  // Too many arguments passed behavior - ignore additional arguments
+  const ev = new Event('foo', {}, {});
+  strictEqual(ev.type, 'foo');
+}
 {
   const ev = new Event('foo', { cancelable: true });
   strictEqual(ev.type, 'foo');