Core: Update isFunction to handle unusual-@@toStringTag input

gibson042 · web-flow · commit a16339b8933f · 2017-04-24T12:39:25.000-04:00
Ref gh-3597 Fixes gh-3600 Fixes gh-3596 Closes gh-3617
diff --git a/src/core.js b/src/core.js
@@ -212,7 +212,12 @@ jQuery.extend( {
 	noop: function() {},
 
 	isFunction: function( obj ) {
-		return jQuery.type( obj ) === "function";
+
+		// Support: Chrome <=57, Firefox <=52
+		// In some browsers, typeof returns "function" for HTML <object> elements
+		// (i.e., `typeof document.createElement( "object" ) === "function"`).
+		// We don't want to classify *any* DOM node as a function.
+		return typeof obj === "function" && typeof obj.nodeType !== "number";
 	},
 
 	isWindow: function( obj ) {
@@ -464,7 +469,7 @@ function isArrayLike( obj ) {
 	var length = !!obj && "length" in obj && obj.length,
 		type = jQuery.type( obj );
 
-	if ( type === "function" || jQuery.isWindow( obj ) ) {
+	if ( jQuery.isFunction( obj ) || jQuery.isWindow( obj ) ) {
 		return false;
 	}
 
diff --git a/test/unit/core.js b/test/unit/core.js
@@ -406,7 +406,7 @@ QUnit[ "assign" in Object ? "test" : "skip" ]( "isPlainObject(Object.assign(...)
 
 
 QUnit.test( "isFunction", function( assert ) {
-	assert.expect( 19 );
+	assert.expect( 20 );
 
 	var mystr, myarr, myfunction, fn, obj, nodes, first, input, a;
 
@@ -439,9 +439,11 @@ QUnit.test( "isFunction", function( assert ) {
 	fn = function() {};
 	assert.ok( jQuery.isFunction( fn ), "Normal Function" );
 
+	assert.notOk( jQuery.isFunction( Object.create( fn ) ), "custom Function subclass" );
+
 	obj = document.createElement( "object" );
 
-	// Firefox says this is a function
+	// Some versions of Firefox and Chrome say this is a function
 	assert.ok( !jQuery.isFunction( obj ), "Object Element" );
 
 	// Since 1.3, this isn't supported (#2968)
@@ -491,6 +493,64 @@ QUnit.test( "isFunction", function( assert ) {
 	} );
 } );
 
+QUnit.test( "isFunction(cross-realm function)", function( assert ) {
+	assert.expect( 1 );
+
+	var iframe, doc,
+		done = assert.async();
+
+	// Functions from other windows should be matched
+	Globals.register( "iframeDone" );
+	window.iframeDone = function( fn, detail ) {
+		window.iframeDone = undefined;
+		assert.ok( jQuery.isFunction( fn ), "cross-realm function" +
+			( detail ? " - " + detail : "" ) );
+		done();
+	};
+
+	iframe = jQuery( "#qunit-fixture" )[ 0 ].appendChild( document.createElement( "iframe" ) );
+	doc = iframe.contentDocument || iframe.contentWindow.document;
+	doc.open();
+	doc.write( "<body onload='window.parent.iframeDone( function() {} );'>" );
+	doc.close();
+} );
+
+supportjQuery.each(
+	{
+		GeneratorFunction: "function*() {}",
+		AsyncFunction: "async function() {}"
+	},
+	function( subclass, source ) {
+		var fn;
+		try {
+			fn = Function( "return " + source )();
+		} catch ( e ) {}
+
+		QUnit[ fn ? "test" : "skip" ]( "isFunction(" + subclass + ")",
+			function( assert ) {
+				assert.expect( 1 );
+
+				assert.equal( jQuery.isFunction( fn ), true, source );
+			}
+		);
+	}
+);
+
+QUnit[ typeof Symbol === "function" && Symbol.toStringTag ? "test" : "skip" ](
+	"isFunction(custom @@toStringTag)",
+	function( assert ) {
+		assert.expect( 2 );
+
+		var obj = {},
+			fn = function() {};
+		obj[ Symbol.toStringTag ] = "Function";
+		fn[ Symbol.toStringTag ] = "Object";
+
+		assert.equal( jQuery.isFunction( obj ), false, "function-mimicking object" );
+		assert.equal( jQuery.isFunction( fn ), true, "object-mimicking function" );
+	}
+);
+
 QUnit.test( "isNumeric", function( assert ) {
 	assert.expect( 43 );
 
diff --git a/test/unit/deferred.js b/test/unit/deferred.js
@@ -526,9 +526,10 @@ QUnit.test( "jQuery.Deferred.then - spec compatibility", function( assert ) {
 
 	assert.expect( 1 );
 
-	var done = assert.async();
+	var done = assert.async(),
+		defer = jQuery.Deferred();
 
-	var defer = jQuery.Deferred().done( function() {
+	defer.done( function() {
 		setTimeout( done );
 		throw new Error();
 	} );
@@ -542,6 +543,26 @@ QUnit.test( "jQuery.Deferred.then - spec compatibility", function( assert ) {
 	} catch ( _ ) {}
 } );
 
+QUnit[ typeof Symbol === "function" && Symbol.toStringTag ? "test" : "skip" ](
+	"jQuery.Deferred.then - IsCallable determination (gh-3596)",
+	function( assert ) {
+
+		assert.expect( 1 );
+
+		var done = assert.async(),
+			defer = jQuery.Deferred();
+
+		function faker() {
+			assert.ok( true, "handler with non-'Function' @@toStringTag gets invoked" );
+		}
+		faker[ Symbol.toStringTag ] = "String";
+
+		defer.then( faker ).then( done );
+
+		defer.resolve();
+	}
+);
+
 // Test fails in IE9 but is skipped there because console is not active
 QUnit[ window.console ? "test" : "skip" ]( "jQuery.Deferred.exceptionHook", function( assert ) {
 
@@ -861,15 +882,24 @@ QUnit.test( "jQuery.when(nonThenable) - like Promise.resolve", function( assert
 QUnit.test( "jQuery.when(thenable) - like Promise.resolve", function( assert ) {
 	"use strict";
 
-	var CASES = 16,
-		slice = [].slice,
+	var customToStringThen = {
+		then: function( onFulfilled ) {
+			onFulfilled();
+		}
+	};
+	if ( typeof Symbol === "function" ) {
+		customToStringThen.then[ Symbol.toStringTag ] = "String";
+	}
+
+	var slice = [].slice,
 		sentinel = { context: "explicit" },
 		eventuallyFulfilled = jQuery.Deferred().notify( true ),
 		eventuallyRejected = jQuery.Deferred().notify( true ),
 		secondaryFulfilled = jQuery.Deferred().resolve( eventuallyFulfilled ),
 		secondaryRejected = jQuery.Deferred().resolve( eventuallyRejected ),
 		inputs = {
 			promise: Promise.resolve( true ),
+			customToStringThen: customToStringThen,
 			rejectedPromise: Promise.reject( false ),
 			deferred: jQuery.Deferred().resolve( true ),
 			eventuallyFulfilled: eventuallyFulfilled,
@@ -894,6 +924,7 @@ QUnit.test( "jQuery.when(thenable) - like Promise.resolve", function( assert ) {
 		},
 		willSucceed = {
 			promise: [ true ],
+			customToStringThen: [],
 			deferred: [ true ],
 			eventuallyFulfilled: [ true ],
 			secondaryFulfilled: [ true ],
@@ -912,14 +943,15 @@ QUnit.test( "jQuery.when(thenable) - like Promise.resolve", function( assert ) {
 			rejectedDeferredWith: [ false ],
 			multiRejectedDeferredWith: [ "baz", "quux" ]
 		},
+		numCases = Object.keys( willSucceed ).length + Object.keys( willError ).length,
 
 		// Support: Android 4.0 only
 		// Strict mode functions invoked without .call/.apply get global-object context
 		defaultContext = ( function getDefaultContext() { return this; } ).call(),
 
-		done = assert.async( CASES * 2 );
+		done = assert.async( numCases * 2 );
 
-	assert.expect( CASES * 4 );
+	assert.expect( numCases * 4 );
 
 	jQuery.each( inputs, function( message, value ) {
 		var code = "jQuery.when( " + message + " )",
