Core: deprecate jQuery.isFunction

Fixes gh-3609

8 files changed, 164 insertions, 159 deletions

diff --git a/test/data/testinit.js b/test/data/testinit.js
index d6c0236e6..211824a89 100644
--- a/test/data/testinit.js
+++ b/test/data/testinit.js
@@ -171,7 +171,7 @@ this.ajaxTest = function( title, expect, options ) {
 	QUnit.test( title, expect, function( assert ) {
 		var requestOptions;
 
-		if ( jQuery.isFunction( options ) ) {
+		if ( typeof options === "function" ) {
 			options = options( assert );
 		}
 		options = options || [];
@@ -208,7 +208,7 @@ this.ajaxTest = function( title, expect, options ) {
 							if ( !completed ) {
 								if ( !handler ) {
 									assert.ok( false, "unexpected " + status );
-								} else if ( jQuery.isFunction( handler ) ) {
+								} else if ( typeof handler === "function" ) {
 									handler.apply( this, arguments );
 								}
 							}
diff --git a/test/unit/basic.js b/test/unit/basic.js
index b46a04c28..29042caa5 100644
--- a/test/unit/basic.js
+++ b/test/unit/basic.js
@@ -76,7 +76,7 @@ QUnit.test( "show/hide", function( assert ) {
 }
 
 QUnit.test( "core", function( assert ) {
-	assert.expect( 25 );
+	assert.expect( 23 );
 
 	var elem = jQuery( "<div></div><span></span>" );
 
@@ -90,9 +90,6 @@ QUnit.test( "core", function( assert ) {
 	assert.ok( jQuery.isPlainObject( { "a": 2 } ), "jQuery.isPlainObject(object)" );
 	assert.ok( !jQuery.isPlainObject( "foo" ), "jQuery.isPlainObject(String)" );
 
-	assert.ok( jQuery.isFunction( jQuery.noop ), "jQuery.isFunction(jQuery.noop)" );
-	assert.ok( !jQuery.isFunction( 2 ), "jQuery.isFunction(Number)" );
-
 	assert.ok( jQuery.isNumeric( "-2" ), "jQuery.isNumeric(String representing a number)" );
 	assert.ok( !jQuery.isNumeric( "" ), "jQuery.isNumeric(\"\")" );
 
diff --git a/test/unit/core.js b/test/unit/core.js
index 7c7514ccc..fcff895b1 100644
--- a/test/unit/core.js
+++ b/test/unit/core.js
@@ -404,153 +404,6 @@ QUnit[ "assign" in Object ? "test" : "skip" ]( "isPlainObject(Object.assign(...)
 	}
 );
 
-
-QUnit.test( "isFunction", function( assert ) {
-	assert.expect( 20 );
-
-	var mystr, myarr, myfunction, fn, obj, nodes, first, input, a;
-
-	// Make sure that false values return false
-	assert.ok( !jQuery.isFunction(), "No Value" );
-	assert.ok( !jQuery.isFunction( null ), "null Value" );
-	assert.ok( !jQuery.isFunction( undefined ), "undefined Value" );
-	assert.ok( !jQuery.isFunction( "" ), "Empty String Value" );
-	assert.ok( !jQuery.isFunction( 0 ), "0 Value" );
-
-	// Check built-ins
-	assert.ok( jQuery.isFunction( String ), "String Function(" + String + ")" );
-	assert.ok( jQuery.isFunction( Array ), "Array Function(" + Array + ")" );
-	assert.ok( jQuery.isFunction( Object ), "Object Function(" + Object + ")" );
-	assert.ok( jQuery.isFunction( Function ), "Function Function(" + Function + ")" );
-
-	// When stringified, this could be misinterpreted
-	mystr = "function";
-	assert.ok( !jQuery.isFunction( mystr ), "Function String" );
-
-	// When stringified, this could be misinterpreted
-	myarr = [ "function" ];
-	assert.ok( !jQuery.isFunction( myarr ), "Function Array" );
-
-	// When stringified, this could be misinterpreted
-	myfunction = { "function": "test" };
-	assert.ok( !jQuery.isFunction( myfunction ), "Function Object" );
-
-	// Make sure normal functions still work
-	fn = function() {};
-	assert.ok( jQuery.isFunction( fn ), "Normal Function" );
-
-	assert.notOk( jQuery.isFunction( Object.create( fn ) ), "custom Function subclass" );
-
-	obj = document.createElement( "object" );
-
-	// 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)
-	//ok( jQuery.isFunction(obj.getAttribute), "getAttribute Function" );
-
-	nodes = document.body.childNodes;
-
-	// Safari says this is a function
-	assert.ok( !jQuery.isFunction( nodes ), "childNodes Property" );
-
-	first = document.body.firstChild;
-
-	// Normal elements are reported ok everywhere
-	assert.ok( !jQuery.isFunction( first ), "A normal DOM Element" );
-
-	input = document.createElement( "input" );
-	input.type = "text";
-	document.body.appendChild( input );
-
-	// Since 1.3, this isn't supported (#2968)
-	//ok( jQuery.isFunction(input.focus), "A default function property" );
-
-	document.body.removeChild( input );
-
-	a = document.createElement( "a" );
-	a.href = "some-function";
-	document.body.appendChild( a );
-
-	// This serializes with the word 'function' in it
-	assert.ok( !jQuery.isFunction( a ), "Anchor Element" );
-
-	document.body.removeChild( a );
-
-	// Recursive function calls have lengths and array-like properties
-	function callme( callback ) {
-		function fn( response ) {
-			callback( response );
-		}
-
-		assert.ok( jQuery.isFunction( fn ), "Recursive Function Call" );
-
-		fn( { some: "data" } );
-	}
-
-	callme( function() {
-		callme( function() {} );
-	} );
-} );
-
-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
index f64d4fec8..9ba97181d 100644
--- a/test/unit/deferred.js
+++ b/test/unit/deferred.js
@@ -14,7 +14,7 @@ jQuery.each( [ "", " - new operator" ], function( _, withNew ) {
 
 		var defer = createDeferred();
 
-		assert.ok( jQuery.isFunction( defer.pipe ), "defer.pipe is a function" );
+		assert.ok( typeof defer.pipe === "function", "defer.pipe is a function" );
 
 		defer.resolve().done( function() {
 			assert.ok( true, "Success on resolve" );
@@ -49,7 +49,7 @@ jQuery.each( [ "", " - new operator" ], function( _, withNew ) {
 			assert.strictEqual( defer.promise(), promise, "promise is always the same" );
 			assert.strictEqual( funcPromise, func, "non objects get extended" );
 			jQuery.each( promise, function( key ) {
-				if ( !jQuery.isFunction( promise[ key ] ) ) {
+				if ( typeof promise[ key ] !== "function" ) {
 					assert.ok( false, key + " is a function (" + jQuery.type( promise[ key ] ) + ")" );
 				}
 				if ( promise[ key ] !== func[ key ] ) {
@@ -1097,7 +1097,7 @@ QUnit.test( "jQuery.when - always returns a new promise", function( assert ) {
 	}, function( label, args ) {
 		var result = jQuery.when.apply( jQuery, args );
 
-		assert.ok( jQuery.isFunction( result.then ), "Thenable returned from " + label );
+		assert.ok( typeof result.then === "function", "Thenable returned from " + label );
 		assert.strictEqual( result.resolve, undefined, "Non-deferred returned from " + label );
 		assert.strictEqual( result.promise(), result, "Promise returned from " + label );
 
diff --git a/test/unit/deprecated.js b/test/unit/deprecated.js
index 9837b3bae..19810151f 100644
--- a/test/unit/deprecated.js
+++ b/test/unit/deprecated.js
@@ -165,6 +165,161 @@ QUnit.test( "jQuery.nodeName", function( assert ) {
 	);
 } );
 
+
+QUnit.test( "core", function( assert ) {
+	assert.expect( 2 );
+
+	assert.ok( jQuery.isFunction( jQuery.noop ), "jQuery.isFunction(jQuery.noop)" );
+	assert.ok( !jQuery.isFunction( 2 ), "jQuery.isFunction(Number)" );
+} );
+
+
+QUnit.test( "isFunction", function( assert ) {
+	assert.expect( 20 );
+
+	var mystr, myarr, myfunction, fn, obj, nodes, first, input, a;
+
+	// Make sure that false values return false
+	assert.ok( !jQuery.isFunction(), "No Value" );
+	assert.ok( !jQuery.isFunction( null ), "null Value" );
+	assert.ok( !jQuery.isFunction( undefined ), "undefined Value" );
+	assert.ok( !jQuery.isFunction( "" ), "Empty String Value" );
+	assert.ok( !jQuery.isFunction( 0 ), "0 Value" );
+
+	// Check built-ins
+	assert.ok( jQuery.isFunction( String ), "String Function(" + String + ")" );
+	assert.ok( jQuery.isFunction( Array ), "Array Function(" + Array + ")" );
+	assert.ok( jQuery.isFunction( Object ), "Object Function(" + Object + ")" );
+	assert.ok( jQuery.isFunction( Function ), "Function Function(" + Function + ")" );
+
+	// When stringified, this could be misinterpreted
+	mystr = "function";
+	assert.ok( !jQuery.isFunction( mystr ), "Function String" );
+
+	// When stringified, this could be misinterpreted
+	myarr = [ "function" ];
+	assert.ok( !jQuery.isFunction( myarr ), "Function Array" );
+
+	// When stringified, this could be misinterpreted
+	myfunction = { "function": "test" };
+	assert.ok( !jQuery.isFunction( myfunction ), "Function Object" );
+
+	// Make sure normal functions still work
+	fn = function() {};
+	assert.ok( jQuery.isFunction( fn ), "Normal Function" );
+
+	assert.notOk( jQuery.isFunction( Object.create( fn ) ), "custom Function subclass" );
+
+	obj = document.createElement( "object" );
+
+	// 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)
+	//ok( jQuery.isFunction(obj.getAttribute), "getAttribute Function" );
+
+	nodes = document.body.childNodes;
+
+	// Safari says this is a function
+	assert.ok( !jQuery.isFunction( nodes ), "childNodes Property" );
+
+	first = document.body.firstChild;
+
+	// Normal elements are reported ok everywhere
+	assert.ok( !jQuery.isFunction( first ), "A normal DOM Element" );
+
+	input = document.createElement( "input" );
+	input.type = "text";
+	document.body.appendChild( input );
+
+	// Since 1.3, this isn't supported (#2968)
+	//ok( jQuery.isFunction(input.focus), "A default function property" );
+
+	document.body.removeChild( input );
+
+	a = document.createElement( "a" );
+	a.href = "some-function";
+	document.body.appendChild( a );
+
+	// This serializes with the word 'function' in it
+	assert.ok( !jQuery.isFunction( a ), "Anchor Element" );
+
+	document.body.removeChild( a );
+
+	// Recursive function calls have lengths and array-like properties
+	function callme( callback ) {
+		function fn( response ) {
+			callback( response );
+		}
+
+		assert.ok( jQuery.isFunction( fn ), "Recursive Function Call" );
+
+		fn( { some: "data" } );
+	}
+
+	callme( function() {
+		callme( function() {} );
+	} );
+} );
+
+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( "jQuery.isWindow", function( assert ) {
 	assert.expect( 14 );
 
diff --git a/test/unit/effects.js b/test/unit/effects.js
index d023dc8c1..462524ef3 100644
--- a/test/unit/effects.js
+++ b/test/unit/effects.js
@@ -2507,7 +2507,7 @@ function testEasing( assert, speed, easing, complete ) {
 
 	assert.equal( options.duration, 10, "Duration set properly" );
 	assert.equal(
-		jQuery.isFunction( options.easing ) ? options.easing() : options.easing,
+		typeof options.easing === "function" ? options.easing() : options.easing,
 		"linear",
 		"Easing set properly"
 	);
diff --git a/test/unit/manipulation.js b/test/unit/manipulation.js
index 528a192ce..07ab43419 100644
--- a/test/unit/manipulation.js
+++ b/test/unit/manipulation.js
@@ -1415,7 +1415,7 @@ QUnit.test( "jQuery.clone() (#8017)", function( assert ) {
 
 	assert.expect( 2 );
 
-	assert.ok( jQuery.clone && jQuery.isFunction( jQuery.clone ), "jQuery.clone() utility exists and is a function." );
+	assert.ok( jQuery.clone && typeof jQuery.clone === "function", "jQuery.clone() utility exists and is a function." );
 
 	var main = jQuery( "#qunit-fixture" )[ 0 ],
 		clone = jQuery.clone( main );
diff --git a/test/unit/queue.js b/test/unit/queue.js
index 0a6862d6b..f604cea04 100644
--- a/test/unit/queue.js
+++ b/test/unit/queue.js
@@ -261,7 +261,7 @@ QUnit.test( ".promise(obj)", function( assert ) {
 	var obj = {},
 		promise = jQuery( "#foo" ).promise( "promise", obj );
 
-	assert.ok( jQuery.isFunction( promise.promise ), ".promise(type, obj) returns a promise" );
+	assert.ok( typeof promise.promise === "function", ".promise(type, obj) returns a promise" );
 	assert.strictEqual( promise, obj, ".promise(type, obj) returns obj" );
 } );