Core: Support Symbol wrapper objects in jQuery.type

In ECMAScript 2015 (ES6), the native typeof operator returns "symbol"
for Symbol primitives. As it is possible to wrap symbols using the
Object constructor, symbols can be objects as well as any other
primitive type in JavaScript and should be determined by jQuery.type.

Closes gh-2627

2 files changed, 14 insertions, 1 deletions

diff --git a/src/core.js b/src/core.js
index 3b42d73ab..b1483c018 100644
--- a/src/core.js
+++ b/src/core.js
@@ -442,7 +442,7 @@ if ( typeof Symbol === "function" ) {
 /* jshint ignore: end */
 
 // Populate the class2type map
-jQuery.each( "Boolean Number String Function Array Date RegExp Object Error".split( " " ),
+jQuery.each( "Boolean Number String Function Array Date RegExp Object Error Symbol".split( " " ),
 function( i, name ) {
 	class2type[ "[object " + name + "]" ] = name.toLowerCase();
 } );
diff --git a/test/unit/core.js b/test/unit/core.js
index 407ae7e2c..42bfe91c1 100644
--- a/test/unit/core.js
+++ b/test/unit/core.js
@@ -272,6 +272,19 @@ QUnit.test( "type", function( assert ) {
 	assert.equal( jQuery.type( new MyObject() ), "object", "Object" );
 } );
 
+QUnit.test( "type for `Symbol`", function( assert ) {
+	// Prevent reference errors
+	if( typeof Symbol !== "function" ) {
+		assert.expect( 0 );
+		return
+	}
+
+	assert.expect( 2 );
+
+	assert.equal( jQuery.type( Symbol() ), "symbol", "Symbol" );
+	assert.equal( jQuery.type( Object( Symbol() ) ), "symbol", "Symbol" );
+});
+
 QUnit.asyncTest( "isPlainObject", function( assert ) {
 	assert.expect( 15 );