Build: Make Karma work in ES modules mode

Also, run such a suite in CI to make sure modules are working as expected
when used directly.

Closes gh-4550

1 files changed, 14 insertions, 0 deletions

diff --git a/test/data/testinit-jsdom.js b/test/data/testinit-jsdom.js
index 37e57d8c4..bdb3c178e 100644
--- a/test/data/testinit-jsdom.js
+++ b/test/data/testinit-jsdom.js
@@ -41,3 +41,17 @@ function url( value ) {
 	return baseURL + value + ( /\?/.test( value ) ? "&" : "?" ) +
 		new Date().getTime() + "" + parseInt( Math.random() * 100000, 10 );
 }
+
+// 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() {
+
+	// Delay the initialization until after all the files are loaded
+	// as in the JSDOM case we load them via Karma (see Gruntfile.js)
+	// instead of directly in testinit.js.
+	window.addEventListener( "load", function() {
+		window.__karma__.start();
+		jQuery.noConflict();
+		QUnit.start();
+	} );
+};