Core: Test all factory use cases from intro.js

There is a lot of logic in intro.js; now we test four cases:
1. (implicitly, via QUnit tests) A real browser with window being the global
2. Browserify where there are both global & window variables.
3. Node with jsdom where window is passed manually to the jQuery factory.
4. Pure Node with incorrect window passed; jQuery should throw then.

Previously the second & fourth case was not tested and the third was tested
in a way that interfered with the main test environment.

We now also test if in the Browserify case we're not creating a jQuery global
by default.

Fixes gh-2181
Closes gh-2234

test/node_smoke_tests/document_missing.js

@@ -0,0 +1,19 @@
+/* jshint node: true */
+
+"use strict";
+
+var ensureGlobalNotCreated = require( "./lib/ensure_global_not_created" ),
+	jQueryFactory = require( "../../dist/jquery.js" );
+
+try {
+	jQueryFactory( {} );
+	console.error( "The jQuery factory should reject window without a document" );
+	process.exit( 1 );
+} catch ( e ) {
+	if ( e.message ===  "jQuery requires a window with a document" ) {
+		ensureGlobalNotCreated( module.exports );
+		process.exit( 0 );
+	}
+	console.error( "An unexpected error thrown; message: ", e.message );
+	process.exit( 1 );
+}

test/node_smoke_tests/document_passed.js

@@ -0,0 +1,17 @@
+/* jshint node: true */
+
+"use strict";
+
+require( "jsdom" ).env( "", function( errors, window ) {
+	if ( errors ) {
+		console.error( errors );
+		process.exit( 1 );
+	}
+
+	var ensureJQuery = require( "./lib/ensure_jquery" ),
+		ensureGlobalNotCreated = require( "./lib/ensure_global_not_created" ),
+		jQuery = require( "../../dist/jquery.js" )( window );
+
+	ensureJQuery( jQuery );
+	ensureGlobalNotCreated( module.exports );
+} );

test/node_smoke_tests/document_present_originally.js

@@ -0,0 +1,20 @@
+/* jshint node: true */
+
+"use strict";
+
+require( "jsdom" ).env( "", function( errors, window ) {
+	if ( errors ) {
+		console.error( errors );
+		process.exit( 1 );
+	}
+
+	// Pretend the window is a global.
+	global.window = window;
+
+	var ensureJQuery = require( "./lib/ensure_jquery" ),
+		ensureGlobalNotCreated = require( "./lib/ensure_global_not_created" ),
+		jQuery = require( "../../dist/jquery.js" );
+
+	ensureJQuery( jQuery );
+	ensureGlobalNotCreated( module.exports, window );
+} );

test/node_smoke_tests/lib/ensure_global_not_created.js

@@ -0,0 +1,17 @@
+/* jshint node: true */
+
+"use strict";
+
+// Ensure the jQuery property on global/window/module.exports/etc. was not
+// created in a CommonJS environment.
+// `global` is always checked in addition to passed parameters.
+module.exports = function ensureGlobalNotCreated() {
+	var args = [].slice.call( arguments ).concat( global );
+
+	args.forEach( function( object ) {
+		if ( object.jQuery ) {
+			console.error( "A jQuery global was created in a CommonJS environment." );
+			process.exit( 1 );
+		}
+	} );
+};

test/node_smoke_tests/lib/ensure_jquery.js

@@ -0,0 +1,11 @@
+/* jshint node: true */
+
+"use strict";
+
+// Check if the object we got is the jQuery object by invoking a basic API.
+module.exports = function ensureJQuery( jQuery ) {
+	if ( !/^jQuery/.test( jQuery.expando ) ) {
+		console.error( "jQuery.expando was not detected, the jQuery bootstrap process has failed" );
+		process.exit( 1 );
+	}
+};