Tests: Exclude tests based on compilation flags, not API presence (3.x version)

Introduces a new test API, `includesModule`. The method returns whether
a particular module like "ajax" or "deprecated" is included in the current
jQuery build; it handles the slim build as well. The util was created so that
we don't treat presence of particular APIs to decide whether to run a test as
then if we accidentally remove an API, the tests would still not fail.

Closes gh-5071
Fixes gh-5069
Ref gh-5046

(partially cherry picked from commit fae5fee8b435cc20352d28b0a384b9784b1ad9ed)

24 files changed, 162 insertions, 75 deletions

diff --git a/build/tasks/build.js b/build/tasks/build.js
index bdde74cee..71c20a81a 100644
--- a/build/tasks/build.js
+++ b/build/tasks/build.js
@@ -9,6 +9,7 @@
 module.exports = function( grunt ) {
 	var fs = require( "fs" ),
 		requirejs = require( "requirejs" ),
+		slimBuildFlags = require( "./lib/slim-build-flags" ),
 		Insight = require( "insight" ),
 		pkg = require( "../../package.json" ),
 		srcFolder = __dirname + "/../../src/",
@@ -348,7 +349,7 @@ module.exports = function( grunt ) {
 					// the official slim build
 					.reduce( ( acc, elem ) => acc.concat(
 						elem === "slim" ?
-							[ "-ajax", "-effects" ] :
+							slimBuildFlags :
 							[ elem ]
 					), [] )
 
diff --git a/build/tasks/lib/slim-build-flags.js b/build/tasks/lib/slim-build-flags.js
new file mode 100644
index 000000000..ac34692fa
--- /dev/null
+++ b/build/tasks/lib/slim-build-flags.js
@@ -0,0 +1,7 @@
+"use strict";
+
+// NOTE: keep it in sync with test/data/testinit.js
+module.exports = [
+	"-ajax",
+	"-effects"
+];
diff --git a/test/.eslintrc.json b/test/.eslintrc.json
index 4d85386e6..bd4d3e98f 100644
--- a/test/.eslintrc.json
+++ b/test/.eslintrc.json
@@ -19,6 +19,7 @@
 		"testIframe": false,
 		"createDashboardXML": false,
 		"createXMLFragment": false,
+		"includesModule": false,
 		"moduleTeardown": false,
 		"url": false,
 		"q": false,
diff --git a/test/data/testinit-jsdom.js b/test/data/testinit-jsdom.js
index bedf093a9..9aa0e0193 100644
--- a/test/data/testinit-jsdom.js
+++ b/test/data/testinit-jsdom.js
@@ -39,6 +39,12 @@ function url( value ) {
 		new Date().getTime() + "" + parseInt( Math.random() * 100000, 10 );
 }
 
+// We only run basic tests in jsdom so we don't need to repeat the logic
+// from the regular testinit.js
+this.includesModule = function() {
+	return true;
+};
+
 // The file-loading part of testinit.js#loadTests is handled by
 // jsdom Karma config; here we just need to trigger relevant APIs.
 this.loadTests = function() {
diff --git a/test/data/testinit.js b/test/data/testinit.js
index 9aef2eda2..f7e57da6d 100644
--- a/test/data/testinit.js
+++ b/test/data/testinit.js
@@ -15,7 +15,13 @@ var FILEPATH = "/test/data/testinit.js",
 	supportjQuery = this.jQuery,
 
 	// see RFC 2606
-	externalHost = "example.com";
+	externalHost = "example.com",
+
+	// NOTE: keep it in sync with build/tasks/lib/slim-build-flags.js
+	slimBuildFlags = [
+		"-ajax",
+		"-effects"
+	];
 
 this.hasPHP = true;
 this.isLocal = window.location.protocol === "file:";
@@ -309,6 +315,58 @@ function moduleTypeSupported() {
 }
 moduleTypeSupported();
 
+// Returns whether a particular module like "ajax" or "deprecated"
+// is included in the current jQuery build; it handles the slim build
+// as well. The util was created so that we don't treat presence of
+// particular APIs to decide whether to run a test as then if we
+// accidentally remove an API, the tests would still not fail.
+this.includesModule = function( moduleName ) {
+
+	var excludedModulesPart, excludedModules;
+
+	// A short-cut for the slim build, e.g. "4.0.0-pre slim"
+	if ( jQuery.fn.jquery.indexOf( " slim" ) > -1 ) {
+
+		// The module is included if it does NOT exist on the list
+		// of modules excluded in the slim build
+		return slimBuildFlags.indexOf( "-" + moduleName ) === -1;
+	}
+
+	// example version for `grunt custom:-deprecated`:
+	// "4.0.0-pre -deprecated,-deprecated/ajax-event-alias,-deprecated/event"
+	excludedModulesPart = jQuery.fn.jquery
+
+		// Take the flags out of the version string.
+		// Example: "-deprecated,-deprecated/ajax-event-alias,-deprecated/event"
+		.split( " " )[ 1 ];
+
+	if ( !excludedModulesPart ) {
+
+		// No build part => the full build where everything is included.
+		return true;
+	}
+
+	excludedModules = excludedModulesPart
+
+		// Turn to an array.
+		// Example: [ "-deprecated", "-deprecated/ajax-event-alias", "-deprecated/event" ]
+		.split( "," )
+
+		// Remove the leading "-".
+		// Example: [ "deprecated", "deprecated/ajax-event-alias", "deprecated/event" ]
+		.map( function( moduleName ) {
+			return moduleName.slice( 1 );
+		} )
+
+		// Filter out deep names - ones that contain a slash.
+		// Example: [ "deprecated" ]
+		.filter( function( moduleName ) {
+			return moduleName.indexOf( "/" ) === -1;
+		} );
+
+	return excludedModules.indexOf( moduleName ) === -1;
+};
+
 this.loadTests = function() {
 
 	// QUnit.config is populated from QUnit.urlParams but only at the beginning
diff --git a/test/unit/ajax.js b/test/unit/ajax.js
index a9f629fec..c4f3cc4c3 100644
--- a/test/unit/ajax.js
+++ b/test/unit/ajax.js
@@ -13,7 +13,7 @@ QUnit.module( "ajax", {
 		assert.ok( !isLocal, "Unit tests are not ran from file:// (especially in Chrome. If you must test from file:// with Chrome, run it with the --allow-file-access-from-files flag!)" );
 	} );
 
-	if ( !jQuery.ajax || ( isLocal && !hasPHP ) ) {
+	if ( !includesModule( "ajax" ) || ( isLocal && !hasPHP ) ) {
 		return;
 	}
 
diff --git a/test/unit/animation.js b/test/unit/animation.js
index 7a51add31..ea30dce19 100644
--- a/test/unit/animation.js
+++ b/test/unit/animation.js
@@ -1,7 +1,7 @@
 ( function() {
 
 // Can't test what ain't there
-if ( !jQuery.fx ) {
+if ( !includesModule( "effects" ) ) {
 	return;
 }
 
diff --git a/test/unit/attributes.js b/test/unit/attributes.js
index 787dd3a02..f690963c8 100644
--- a/test/unit/attributes.js
+++ b/test/unit/attributes.js
@@ -944,7 +944,7 @@ QUnit.test( "val()", function( assert ) {
 		"Select-one with only option disabled (trac-12584)"
 	);
 
-	if ( jQuery.fn.serialize ) {
+	if ( includesModule( "serialize" ) ) {
 		checks = jQuery( "<input type='checkbox' name='test' value='1'/><input type='checkbox' name='test' value='2'/><input type='checkbox' name='test' value=''/><input type='checkbox' name='test'/>" ).appendTo( "#form" );
 
 		assert.deepEqual( checks.serialize(), "", "Get unchecked values." );
diff --git a/test/unit/basic.js b/test/unit/basic.js
index aadf36fa3..ba785ae9f 100644
--- a/test/unit/basic.js
+++ b/test/unit/basic.js
@@ -1,6 +1,6 @@
 QUnit.module( "basic", { afterEach: moduleTeardown } );
 
-if ( jQuery.ajax ) {
+if ( includesModule( "ajax" ) ) {
 QUnit.test( "ajax", function( assert ) {
 	assert.expect( 4 );
 
@@ -33,6 +33,7 @@ QUnit.test( "ajax", function( assert ) {
 } );
 }
 
+if ( includesModule( "attributes" ) ) {
 QUnit.test( "attributes", function( assert ) {
 	assert.expect( 6 );
 
@@ -51,8 +52,9 @@ QUnit.test( "attributes", function( assert ) {
 
 	assert.strictEqual( input.val( "xyz" ).val(), "xyz", ".val getter/setter" );
 } );
+}
 
-if ( jQuery.css ) {
+if ( includesModule( "css" ) ) {
 QUnit.test( "css", function( assert ) {
 	assert.expect( 1 );
 
@@ -62,7 +64,7 @@ QUnit.test( "css", function( assert ) {
 } );
 }
 
-if ( jQuery.fn.show && jQuery.fn.hide ) {
+if ( includesModule( "css" ) ) {
 QUnit.test( "show/hide", function( assert ) {
 	assert.expect( 2 );
 
@@ -123,6 +125,7 @@ QUnit.test( "core", function( assert ) {
 		2, "jQuery.parseHTML" );
 } );
 
+if ( includesModule( "data" ) ) {
 QUnit.test( "data", function( assert ) {
 	assert.expect( 4 );
 
@@ -133,7 +136,9 @@ QUnit.test( "data", function( assert ) {
 	assert.strictEqual( elem.data( "c" ), "d", ".data from data-* attributes" );
 	assert.ok( jQuery.hasData( elem[ 0 ] ), "jQuery.hasData - true" );
 } );
+}
 
+if ( includesModule( "dimensions" ) ) {
 QUnit.test( "dimensions", function( assert ) {
 	assert.expect( 3 );
 
@@ -145,7 +150,9 @@ QUnit.test( "dimensions", function( assert ) {
 	assert.strictEqual( elem.innerWidth(), 64, ".innerWidth getter" );
 	assert.strictEqual( elem.outerWidth(), 68, ".outerWidth getter" );
 } );
+}
 
+if ( includesModule( "event" ) ) {
 QUnit.test( "event", function( assert ) {
 	assert.expect( 1 );
 
@@ -162,7 +169,9 @@ QUnit.test( "event", function( assert ) {
 		} )
 		.trigger( "click" );
 } );
+}
 
+if ( includesModule( "manipulation" ) ) {
 QUnit.test( "manipulation", function( assert ) {
 	assert.expect( 5 );
 
@@ -191,6 +200,9 @@ QUnit.test( "manipulation", function( assert ) {
 		".after/.before"
 	);
 } );
+}
+
+if ( includesModule( "offset" ) ) {
 
 // Support: jsdom 13.2+
 // jsdom returns 0 for offset-related properties
@@ -204,6 +216,7 @@ QUnit[ /jsdom\//.test( navigator.userAgent ) ? "skip" : "test" ]( "offset", func
 	assert.strictEqual( elem.position().top, 5, ".position getter" );
 	assert.strictEqual( elem.offsetParent()[ 0 ], parent[ 0 ], ".offsetParent" );
 } );
+}
 
 QUnit.test( "selector", function( assert ) {
 	assert.expect( 2 );
@@ -215,6 +228,7 @@ QUnit.test( "selector", function( assert ) {
 	assert.strictEqual( elem.find( "span.b a" )[ 0 ].nodeName, "A", ".find - one result" );
 } );
 
+if ( includesModule( "serialize" ) ) {
 QUnit.test( "serialize", function( assert ) {
 	assert.expect( 2 );
 
@@ -228,6 +242,7 @@ QUnit.test( "serialize", function( assert ) {
 		"&select1=&select2=3&select3=1&select3=2&select5=3",
 		"form serialization as query string" );
 } );
+}
 
 QUnit.test( "traversing", function( assert ) {
 	assert.expect( 12 );
@@ -249,6 +264,7 @@ QUnit.test( "traversing", function( assert ) {
 	assert.strictEqual( elem.contents()[ 3 ].nodeType, 3, ".contents" );
 } );
 
+if ( includesModule( "wrap" ) ) {
 QUnit.test( "wrap", function( assert ) {
 	assert.expect( 3 );
 
@@ -279,3 +295,4 @@ QUnit.test( "wrap", function( assert ) {
 	);
 
 } );
+}
diff --git a/test/unit/callbacks.js b/test/unit/callbacks.js
index 9802e6b97..3f3dc15ec 100644
--- a/test/unit/callbacks.js
+++ b/test/unit/callbacks.js
@@ -4,7 +4,7 @@ QUnit.module( "callbacks", {
 
 ( function() {
 
-if ( !jQuery.Callbacks ) {
+if ( !includesModule( "callbacks" ) ) {
 	return;
 }
 
diff --git a/test/unit/core.js b/test/unit/core.js
index 75266b9cd..a2fe504fc 100644
--- a/test/unit/core.js
+++ b/test/unit/core.js
@@ -36,23 +36,23 @@ QUnit.test( "jQuery()", function( assert ) {
 
 	// The $(html, props) signature can stealth-call any $.fn method, check for a
 	// few here but beware of modular builds where these methods may be excluded.
-	if ( jQuery.fn.click ) {
+	if ( includesModule( "deprecated" ) ) {
 		expected++;
 		attrObj[ "click" ] = function() { assert.ok( exec, "Click executed." ); };
 	}
-	if ( jQuery.fn.width ) {
+	if ( includesModule( "dimensions" ) ) {
 		expected++;
 		attrObj[ "width" ] = 10;
 	}
-	if ( jQuery.fn.offset ) {
+	if ( includesModule( "offset" ) ) {
 		expected++;
 		attrObj[ "offset" ] = { "top": 1, "left": 1 };
 	}
-	if ( jQuery.fn.css ) {
+	if ( includesModule( "css" ) ) {
 		expected += 2;
 		attrObj[ "css" ] = { "paddingLeft": 1, "paddingRight": 1 };
 	}
-	if ( jQuery.fn.attr ) {
+	if ( includesModule( "attributes" ) ) {
 		expected++;
 		attrObj.attr = { "desired": "very" };
 	}
@@ -115,20 +115,20 @@ QUnit.test( "jQuery()", function( assert ) {
 
 	elem = jQuery( "<div></div>", attrObj );
 
-	if ( jQuery.fn.width ) {
+	if ( includesModule( "dimensions" ) ) {
 		assert.equal( elem[ 0 ].style.width, "10px", "jQuery() quick setter width" );
 	}
 
-	if ( jQuery.fn.offset ) {
+	if ( includesModule( "offset" ) ) {
 		assert.equal( elem[ 0 ].style.top, "1px", "jQuery() quick setter offset" );
 	}
 
-	if ( jQuery.fn.css ) {
+	if ( includesModule( "css" ) ) {
 		assert.equal( elem[ 0 ].style.paddingLeft, "1px", "jQuery quick setter css" );
 		assert.equal( elem[ 0 ].style.paddingRight, "1px", "jQuery quick setter css" );
 	}
 
-	if ( jQuery.fn.attr ) {
+	if ( includesModule( "attributes" ) ) {
 		assert.equal( elem[ 0 ].getAttribute( "desired" ), "very", "jQuery quick setter attr" );
 	}
 
@@ -1536,7 +1536,7 @@ testIframe(
 	}
 );
 
-QUnit[ jQuery.Deferred ? "test" : "skip" ]( "jQuery.readyException (original)", function( assert ) {
+QUnit[ includesModule( "deferred" ) ? "test" : "skip" ]( "jQuery.readyException (original)", function( assert ) {
 	assert.expect( 1 );
 
 	var message;
@@ -1559,7 +1559,7 @@ QUnit[ jQuery.Deferred ? "test" : "skip" ]( "jQuery.readyException (original)",
 	);
 } );
 
-QUnit[ jQuery.Deferred ? "test" : "skip" ]( "jQuery.readyException (custom)", function( assert ) {
+QUnit[ includesModule( "deferred" ) ? "test" : "skip" ]( "jQuery.readyException (custom)", function( assert ) {
 	assert.expect( 1 );
 
 	var done = assert.async();
diff --git a/test/unit/css.js b/test/unit/css.js
index b2b259433..2df877de8 100644
--- a/test/unit/css.js
+++ b/test/unit/css.js
@@ -1,4 +1,4 @@
-if ( jQuery.css ) {
+if ( includesModule( "css" ) ) {
 
 QUnit.module( "css", { afterEach: moduleTeardown } );
 
@@ -487,9 +487,6 @@ QUnit.test( "css(Object) where values are Functions with incoming values", funct
 	jQuery( "#cssFunctionTest" ).remove();
 } );
 
-// .show(), .hide(), can be excluded from the build
-if ( jQuery.fn.show && jQuery.fn.hide ) {
-
 QUnit.test( "show()", function( assert ) {
 
 	assert.expect( 18 );
@@ -968,8 +965,6 @@ QUnit.test( "show/hide 3.0, inline hidden", function( assert ) {
 	} );
 } );
 
-}
-
 QUnit[ jQuery.find.compile && jQuery.fn.toggle ? "test" : "skip" ]( "toggle()", function( assert ) {
 	assert.expect( 9 );
 	var div, oldHide,
@@ -1194,7 +1189,7 @@ QUnit.test( "can't get background-position in IE<9, see trac-10796", function( a
 	}
 } );
 
-if ( jQuery.fn.offset ) {
+if ( includesModule( "offset" ) ) {
 	QUnit.test( "percentage properties for left and top should be transformed to pixels, see trac-9505", function( assert ) {
 		assert.expect( 2 );
 		var parent = jQuery( "<div style='position:relative;width:200px;height:200px;margin:0;padding:0;border-width:0'></div>" ).appendTo( "#qunit-fixture" ),
diff --git a/test/unit/deferred.js b/test/unit/deferred.js
index 0132a0129..184dded95 100644
--- a/test/unit/deferred.js
+++ b/test/unit/deferred.js
@@ -4,7 +4,7 @@ QUnit.module( "deferred", {
 
 ( function() {
 
-if ( !jQuery.Deferred ) {
+if ( !includesModule( "deferred" ) ) {
 	return;
 }
 
diff --git a/test/unit/deprecated.js b/test/unit/deprecated.js
index 2e6455b29..20bea3d2c 100644
--- a/test/unit/deprecated.js
+++ b/test/unit/deprecated.js
@@ -1,7 +1,8 @@
 QUnit.module( "deprecated", { afterEach: moduleTeardown } );
 
+if ( includesModule( "deprecated" ) ) {
 
-QUnit[ jQuery.fn.bind ? "test" : "skip" ]( "bind/unbind", function( assert ) {
+QUnit.test( "bind/unbind", function( assert ) {
 	assert.expect( 4 );
 
 	var markup = jQuery(
@@ -22,7 +23,7 @@ QUnit[ jQuery.fn.bind ? "test" : "skip" ]( "bind/unbind", function( assert ) {
 		.remove();
 } );
 
-QUnit[ jQuery.fn.delegate ? "test" : "skip" ]( "delegate/undelegate", function( assert ) {
+QUnit.test( "delegate/undelegate", function( assert ) {
 	assert.expect( 2 );
 
 	var markup = jQuery(
@@ -41,7 +42,7 @@ QUnit[ jQuery.fn.delegate ? "test" : "skip" ]( "delegate/undelegate", function(
 		.remove();
 } );
 
-QUnit[ jQuery.fn.hover ? "test" : "skip" ]( "hover() mouseenter mouseleave", function( assert ) {
+QUnit.test( "hover() mouseenter mouseleave", function( assert ) {
 	assert.expect( 1 );
 
 	var times = 0,
@@ -61,8 +62,7 @@ QUnit[ jQuery.fn.hover ? "test" : "skip" ]( "hover() mouseenter mouseleave", fun
 	assert.equal( times, 4, "hover handlers fired" );
 } );
 
-
-QUnit[ jQuery.fn.click ? "test" : "skip" ]( "trigger() shortcuts", function( assert ) {
+QUnit.test( "trigger() shortcuts", function( assert ) {
 	assert.expect( 5 );
 
 	var counter, clickCounter,
@@ -96,7 +96,7 @@ QUnit[ jQuery.fn.click ? "test" : "skip" ]( "trigger() shortcuts", function( ass
 	assert.equal( clickCounter, 1, "Check that click, triggers onclick event handler on an a tag also" );
 } );
 
-if ( jQuery.ajax && jQuery.fn.ajaxSend ) {
+if ( includesModule( "ajax" ) ) {
 	ajaxTest( "jQuery.ajax() - events with context", 12, function( assert ) {
 		var context = document.createElement( "div" );
 
@@ -113,10 +113,10 @@ if ( jQuery.ajax && jQuery.fn.ajaxSend ) {
 		return {
 			setup: function() {
 				jQuery( context ).appendTo( "#foo" )
-					.ajaxSend( event )
-					.ajaxComplete( event )
-					.ajaxError( event )
-					.ajaxSuccess( event );
+					.on( "ajaxSend", event )
+					.on( "ajaxComplete", event )
+					.on( "ajaxError", event )
+					.on( "ajaxSuccess", event );
 			},
 			requests: [ {
 				url: url( "name.html" ),
@@ -135,7 +135,7 @@ if ( jQuery.ajax && jQuery.fn.ajaxSend ) {
 	} );
 }
 
-QUnit[ jQuery.fn.click ? "test" : "skip" ]( "Event aliases", function( assert ) {
+QUnit.test( "Event aliases", function( assert ) {
 
 	// Explicitly skipping focus/blur events due to their flakiness
 	var	$elem = jQuery( "<div></div>" ).appendTo( "#qunit-fixture" ),
@@ -153,7 +153,7 @@ QUnit[ jQuery.fn.click ? "test" : "skip" ]( "Event aliases", function( assert )
 	} );
 } );
 
-QUnit[ jQuery.parseJSON ? "test" : "skip" ]( "jQuery.parseJSON", function( assert ) {
+QUnit.test( "jQuery.parseJSON", function( assert ) {
 	assert.expect( 20 );
 
 	assert.strictEqual( jQuery.parseJSON( null ), null, "primitive null" );
@@ -223,13 +223,13 @@ QUnit[ jQuery.parseJSON ? "test" : "skip" ]( "jQuery.parseJSON", function( asser
 	assert.strictEqual( jQuery.parseJSON( [ 0 ] ), 0, "Input cast to string" );
 } );
 
-QUnit[ jQuery.isArray ? "test" : "skip" ]( "jQuery.isArray", function( assert ) {
+QUnit.test( "jQuery.isArray", function( assert ) {
 	assert.expect( 1 );
 
 	assert.strictEqual( jQuery.isArray, Array.isArray, "Array.isArray equals jQuery.isArray" );
 } );
 
-QUnit[ jQuery.nodeName ? "test" : "skip" ]( "jQuery.nodeName", function( assert ) {
+QUnit.test( "jQuery.nodeName", function( assert ) {
 	assert.expect( 8 );
 
 	assert.strictEqual( typeof jQuery.nodeName, "function", "jQuery.nodeName is a function" );
@@ -278,7 +278,7 @@ QUnit[ jQuery.nodeName ? "test" : "skip" ]( "jQuery.nodeName", function( assert
 } );
 
 
-QUnit[ jQuery.type ? "test" : "skip" ]( "type", function( assert ) {
+QUnit.test( "type", function( assert ) {
 	assert.expect( 28 );
 
 	assert.equal( jQuery.type( null ), "null", "null" );
@@ -317,7 +317,7 @@ QUnit[ jQuery.type ? "test" : "skip" ]( "type", function( assert ) {
 	assert.equal( jQuery.type( new MyObject() ), "object", "Object" );
 } );
 
-QUnit[ jQuery.type && typeof Symbol === "function" ? "test" : "skip" ](
+QUnit[ typeof Symbol === "function" ? "test" : "skip" ](
 	"type for `Symbol`", function( assert ) {
 	assert.expect( 2 );
 
@@ -325,7 +325,7 @@ QUnit[ jQuery.type && typeof Symbol === "function" ? "test" : "skip" ](
 	assert.equal( jQuery.type( Object( Symbol() ) ), "symbol", "Symbol" );
 } );
 
-QUnit[ jQuery.isFunction ? "test" : "skip" ]( "isFunction", function( assert ) {
+QUnit.test( "isFunction", function( assert ) {
 	assert.expect( 20 );
 
 	var mystr, myarr, myfunction, fn, obj, nodes, first, input, a;
@@ -413,7 +413,7 @@ QUnit[ jQuery.isFunction ? "test" : "skip" ]( "isFunction", function( assert ) {
 	} );
 } );
 
-QUnit[ jQuery.isFunction ? "test" : "skip" ]( "isFunction(cross-realm function)", function( assert ) {
+QUnit.test( "isFunction(cross-realm function)", function( assert ) {
 	assert.expect( 1 );
 
 	var iframe, doc,
@@ -456,7 +456,7 @@ supportjQuery.each(
 	}
 );
 
-QUnit[ jQuery.isFunction && typeof Symbol === "function" && Symbol.toStringTag ? "test" : "skip" ](
+QUnit[ typeof Symbol === "function" && Symbol.toStringTag ? "test" : "skip" ](
 	"isFunction(custom @@toStringTag)",
 	function( assert ) {
 		assert.expect( 2 );
@@ -471,7 +471,7 @@ QUnit[ jQuery.isFunction && typeof Symbol === "function" && Symbol.toStringTag ?
 	}
 );
 
-QUnit[ jQuery.isWindow ? "test" : "skip" ]( "jQuery.isWindow", function( assert ) {
+QUnit.test( "jQuery.isWindow", function( assert ) {
 	assert.expect( 14 );
 
 	assert.ok( jQuery.isWindow( window ), "window" );
@@ -490,7 +490,7 @@ QUnit[ jQuery.isWindow ? "test" : "skip" ]( "jQuery.isWindow", function( assert
 	assert.ok( !jQuery.isWindow( function() {} ), "function" );
 } );
 
-QUnit[ jQuery.camelCase ? "test" : "skip" ]( "jQuery.camelCase()", function( assert ) {
+QUnit.test( "jQuery.camelCase()", function( assert ) {
 
 	var tests = {
 		"foo-bar": "fooBar",
@@ -509,13 +509,13 @@ QUnit[ jQuery.camelCase ? "test" : "skip" ]( "jQuery.camelCase()", function( ass
 	} );
 } );
 
-QUnit[ jQuery.now ? "test" : "skip" ]( "jQuery.now", function( assert ) {
+QUnit.test( "jQuery.now", function( assert ) {
 	assert.expect( 1 );
 
 	assert.ok( typeof jQuery.now() === "number", "jQuery.now is a function" );
 } );
 
-QUnit[ jQuery.proxy ? "test" : "skip" ]( "jQuery.proxy", function( assert ) {
+QUnit.test( "jQuery.proxy", function( assert ) {
 	assert.expect( 9 );
 
 	var test2, test3, test4, fn, cb,
@@ -563,7 +563,7 @@ QUnit[ jQuery.proxy ? "test" : "skip" ]( "jQuery.proxy", function( assert ) {
 	cb.call( thisObject, "arg3" );
 } );
 
-QUnit[ jQuery.isNumeric ? "test" : "skip" ]( "isNumeric", function( assert ) {
+QUnit.test( "isNumeric", function( assert ) {
 	assert.expect( 43 );
 
 	var t = jQuery.isNumeric,
@@ -631,7 +631,7 @@ QUnit[ jQuery.isNumeric ? "test" : "skip" ]( "isNumeric", function( assert ) {
 	assert.equal( t( new Date() ), false, "Instance of a Date" );
 } );
 
-QUnit[ jQuery.isNumeric && typeof Symbol === "function" ? "test" : "skip" ](
+QUnit[ typeof Symbol === "function" ? "test" : "skip" ](
 	"isNumeric(Symbol)", function( assert ) {
 	assert.expect( 2 );
 
@@ -639,7 +639,7 @@ QUnit[ jQuery.isNumeric && typeof Symbol === "function" ? "test" : "skip" ](
 	assert.equal( jQuery.isNumeric( Object( Symbol() ) ), false, "Symbol inside an object" );
 } );
 
-QUnit[ jQuery.trim ? "test" : "skip" ]( "trim", function( assert ) {
+QUnit.test( "trim", function( assert ) {
 	assert.expect( 13 );
 
 	var nbsp = String.fromCharCode( 160 );
@@ -660,3 +660,5 @@ QUnit[ jQuery.trim ? "test" : "skip" ]( "trim", function( assert ) {
 	assert.equal( jQuery.trim( "\uFEFF" ), "", "zwsp should be trimmed" );
 	assert.equal( jQuery.trim( "\uFEFF \xA0! | \uFEFF" ), "! |", "leading/trailing should be trimmed" );
 } );
+
+}
diff --git a/test/unit/dimensions.js b/test/unit/dimensions.js
index ffdb79579..e5ffbb57a 100644
--- a/test/unit/dimensions.js
+++ b/test/unit/dimensions.js
@@ -1,6 +1,6 @@
 ( function() {
 
-if ( !jQuery.fn.width ) {
+if ( !includesModule( "dimensions" ) ) {
 	return;
 }
 
diff --git a/test/unit/effects.js b/test/unit/effects.js
index 40c5d341b..9b3679835 100644
--- a/test/unit/effects.js
+++ b/test/unit/effects.js
@@ -1,7 +1,7 @@
 ( function() {
 
 // Can't test what ain't there
-if ( !jQuery.fx ) {
+if ( !includesModule( "effects" ) ) {
 	return;
 }
 
diff --git a/test/unit/manipulation.js b/test/unit/manipulation.js
index 1535f0240..348912e6e 100644
--- a/test/unit/manipulation.js
+++ b/test/unit/manipulation.js
@@ -445,7 +445,7 @@ QUnit.test( "append HTML5 sectioning elements (Bug trac-6485)", function( assert
 	assert.equal( aside.length, 1, "HTML5 elements do not collapse their children" );
 } );
 
-if ( jQuery.css ) {
+if ( includesModule( "css" ) ) {
 	QUnit.test( "HTML5 Elements inherit styles from style rules (Bug trac-10501)", function( assert ) {
 
 		assert.expect( 1 );
@@ -2344,7 +2344,7 @@ testIframe(
 	},
 
 	// The AJAX module is needed for jQuery._evalUrl.
-	QUnit[ jQuery.ajax ? "test" : "skip" ]
+	QUnit[ includesModule( "ajax" ) ? "test" : "skip" ]
 );
 
 QUnit.test( "jQuery.clone - no exceptions for object elements trac-9587", function( assert ) {
@@ -2464,7 +2464,7 @@ QUnit.test( "html() - script exceptions bubble (trac-11743)", function( assert )
 	window.onerror = function() {
 		assert.ok( true, "Exception thrown" );
 
-		if ( jQuery.ajax ) {
+		if ( includesModule( "ajax" ) ) {
 			window.onerror = function() {
 				assert.ok( true, "Exception thrown in remote script" );
 			};
@@ -2552,7 +2552,7 @@ QUnit.test( "script evaluation (trac-11795)", function( assert ) {
 	assert.deepEqual( fixture.children( "script" ).get(), scriptsOut.get(), "Scripts detached without reevaluation" );
 	objGlobal.ok = isOk;
 
-	if ( jQuery.ajax ) {
+	if ( includesModule( "ajax" ) ) {
 		Globals.register( "testBar" );
 		jQuery( "#qunit-fixture" ).append( "<script src='" + url( "mock.php?action=testbar" ) + "'></script>" );
 		assert.strictEqual( window.testBar, "bar", "Global script evaluation" );
@@ -2562,7 +2562,7 @@ QUnit.test( "script evaluation (trac-11795)", function( assert ) {
 	}
 } );
 
-QUnit[ jQuery.ajax ? "test" : "skip" ]( "jQuery._evalUrl (trac-12838)", function( assert ) {
+QUnit[ includesModule( "ajax" ) ? "test" : "skip" ]( "jQuery._evalUrl (trac-12838)", function( assert ) {
 
 	assert.expect( 5 );
 
@@ -2853,7 +2853,7 @@ QUnit.test( "Make sure tags with single-character names are found (gh-4124)", fu
 } );
 
 // The AJAX module is needed for jQuery._evalUrl.
-QUnit[ jQuery.ajax ? "test" : "skip" ]( "Insert script with data-URI (gh-1887)", function( assert ) {
+QUnit[ includesModule( "ajax" ) ? "test" : "skip" ]( "Insert script with data-URI (gh-1887)", function( assert ) {
 	assert.expect( 1 );
 	Globals.register( "testFoo" );
 	Globals.register( "testSrcFoo" );
@@ -2943,7 +2943,7 @@ testIframe(
 	// Old iOS & Android Browser versions support script-src but not nonce, making this test
 	// impossible to run. Browsers not supporting CSP at all are not a problem as they'll skip
 	// script-src restrictions completely.
-	QUnit[ jQuery.ajax && !/\bedge\/|iphone os [789]|android 4\./i.test( navigator.userAgent ) ? "test" : "skip" ]
+	QUnit[ includesModule( "ajax" ) && !/\bedge\/|iphone os [789]|android 4\./i.test( navigator.userAgent ) ? "test" : "skip" ]
 );
 
 testIframe(
diff --git a/test/unit/offset.js b/test/unit/offset.js
index 1853c73f6..fba082000 100644
--- a/test/unit/offset.js
+++ b/test/unit/offset.js
@@ -1,6 +1,6 @@
 ( function() {
 
-if ( !jQuery.fn.offset ) {
+if ( !includesModule( "offset" ) ) {
 	return;
 }
 
diff --git a/test/unit/queue.js b/test/unit/queue.js
index 7e124210b..312b37b8c 100644
--- a/test/unit/queue.js
+++ b/test/unit/queue.js
@@ -2,7 +2,7 @@ QUnit.module( "queue", { afterEach: moduleTeardown } );
 
 ( function() {
 
-if ( !jQuery.fn.queue ) {
+if ( !includesModule( "queue" ) ) {
 	return;
 }
 
@@ -241,7 +241,7 @@ QUnit.test( "fn.promise( \"queue\" ) - called whenever last queue function is de
 	foo.dequeue( "queue" );
 } );
 
-if ( jQuery.fn.animate ) {
+if ( includesModule( "effects" ) ) {
 
 QUnit.test( "fn.promise( \"queue\" ) - waits for animation to complete before resolving", function( assert ) {
 	assert.expect( 2 );
@@ -277,7 +277,7 @@ QUnit.test( ".promise(obj)", function( assert ) {
 	assert.strictEqual( promise, obj, ".promise(type, obj) returns obj" );
 } );
 
-QUnit[ jQuery.fn.stop ? "test" : "skip" ]( "delay() can be stopped", function( assert ) {
+QUnit[ includesModule( "effects" ) ? "test" : "skip" ]( "delay() can be stopped", function( assert ) {
 	var done = assert.async();
 	assert.expect( 3 );
 	var storage = {};
@@ -314,7 +314,7 @@ QUnit[ jQuery.fn.stop ? "test" : "skip" ]( "delay() can be stopped", function( a
 	}, 1500 );
 } );
 
-QUnit[ jQuery.fn.stop ? "test" : "skip" ]( "queue stop hooks", function( assert ) {
+QUnit[ includesModule( "effects" ) ? "test" : "skip" ]( "queue stop hooks", function( assert ) {
 	assert.expect( 2 );
 	var done = assert.async();
 	var foo = jQuery( "#foo" );
diff --git a/test/unit/ready.js b/test/unit/ready.js
index d1a728b47..a476528de 100644
--- a/test/unit/ready.js
+++ b/test/unit/ready.js
@@ -105,7 +105,7 @@ QUnit.module( "ready" );
 		} );
 	} );
 
-	QUnit[ jQuery.when ? "test" : "skip" ]( "jQuery.when(jQuery.ready)", function( assert ) {
+	QUnit[ includesModule( "deferred" ) ? "test" : "skip" ]( "jQuery.when(jQuery.ready)", function( assert ) {
 		assert.expect( 2 );
 		var done = assert.async( 2 );
 
@@ -150,7 +150,7 @@ QUnit.module( "ready" );
 	} );
 
 	// jQuery.holdReady is deprecated, skip the test if it was excluded.
-	if ( jQuery.holdReady ) {
+	if ( includesModule( "deprecated" ) ) {
 		testIframe(
 			"holdReady test needs to be a standalone test since it deals with DOM ready",
 			"readywait.html",
diff --git a/test/unit/serialize.js b/test/unit/serialize.js
index 18f7b299d..24d888fb9 100644
--- a/test/unit/serialize.js
+++ b/test/unit/serialize.js
@@ -77,7 +77,7 @@ QUnit.test( "jQuery.param()", function( assert ) {
 	assert.equal( jQuery.param( params ), "", "jQuery.param( undefined ) === empty string" );
 } );
 
-QUnit[ jQuery.ajax ? "test" : "skip" ]( "jQuery.param() not affected by ajaxSettings", function( assert ) {
+QUnit[ includesModule( "ajax" ) ? "test" : "skip" ]( "jQuery.param() not affected by ajaxSettings", function( assert ) {
 	assert.expect( 1 );
 
 	var oldTraditional = jQuery.ajaxSettings.traditional;
diff --git a/test/unit/support.js b/test/unit/support.js
index 7ae6539e4..834bf5ea0 100644
--- a/test/unit/support.js
+++ b/test/unit/support.js
@@ -17,7 +17,7 @@ function getComputedSupport( support ) {
 	return result;
 }
 
-if ( jQuery.css ) {
+if ( includesModule( "css" ) ) {
 	testIframe(
 		"body background is not lost if set prior to loading jQuery (trac-9239)",
 		"support/bodyBackground.html",
@@ -362,7 +362,7 @@ testIframe(
 		assert.expect( j );
 
 		for ( i in expected ) {
-			if ( jQuery.ajax || i !== "ajax" && i !== "cors" ) {
+			if ( includesModule( "ajax" ) || i !== "ajax" && i !== "cors" ) {
 				assert.equal( computedSupport[ i ], expected[ i ],
 					"jQuery.support['" + i + "']: " + computedSupport[ i ] +
 						", expected['" + i + "']: " + expected[ i ] );
diff --git a/test/unit/tween.js b/test/unit/tween.js
index 68c5c0e8d..f41b49ec6 100644
--- a/test/unit/tween.js
+++ b/test/unit/tween.js
@@ -1,7 +1,7 @@
 ( function() {
 
 // Can't test what ain't there
-if ( !jQuery.fx ) {
+if ( !includesModule( "effects" ) ) {
 	return;
 }
 
diff --git a/test/unit/wrap.js b/test/unit/wrap.js
index 1f920129e..24136ac0e 100644
--- a/test/unit/wrap.js
+++ b/test/unit/wrap.js
@@ -1,6 +1,6 @@
 ( function() {
 
-if ( !jQuery.fn.wrap ) { // no wrap module
+if ( !includesModule( "wrap" ) ) {
 	return;
 }