Build: Make dev mode work in Karma again, serve source files from disk

PR gh-4550 added support for running ES modules & AMD tests via Karma. This required reading the `esmodules` & `amd` props from both `QUnit.config` & `QUnit.urlParams`. By picking these two properties manually, the `dev` one stopped being respected while ones handled directly by QUnit were fine (like `hidepassed`). Instead of maintaining the full list of options, the code now iterates over QUnit URL config and handles the fallbacks in a more generic way. Apart from that, all jQuery source & test files are now read directly from disk instead of being cached by Karma so that one can run `grunt karma:chrome-debug` & work on a fix without restarting that Karma run after each change. A similar effect could have been achieved by setting `autoWatch` to `true` but then the main Karma page runs tests in an iframe by default when `grunt karma:chrome-debug` is run instead of relying on the current debug flow. Closes gh-4574 Ref gh-4550

Author: mgol

Gruntfile.js

@@ -158,14 +158,31 @@ module.exports = function( grunt ) {
 
 "test/jquery.js",
 
-{ pattern: "dist/jquery.*", included: false, served: true },
-{ pattern: "src/**", type: "module", included: false, served: true },
-{ pattern: "amd/**", included: false, served: true },
+{
+pattern: "dist/jquery.*",
+included: false,
+served: true,
+nocache: true
+},
+{
+pattern: "src/**",
+type: "module",
+included: false,
+served: true,
+nocache: true
+},
+{
+pattern: "amd/**",
+included: false,
+served: true,
+nocache: true
+},
 { pattern: "node_modules/**", included: false, served: true },
 {
 pattern: "test/**/*.@(js|css|jpg|html|xml|svg)",
 included: false,
-served: true
+served: true,
+nocache: true
 }
 ],
 reporters: [ "dots" ],

test/jquery.js

@@ -2,29 +2,34 @@
 ( function() {
 /* global loadTests: false */
 
-var dynamicImportSource,
+var dynamicImportSource, config, src,
 FILEPATH = "/test/jquery.js",
 activeScript = [].slice.call( document.getElementsByTagName( "script" ), -1 )[ 0 ],
 parentUrl = activeScript && activeScript.src ?
 activeScript.src.replace( /[?#].*/, "" ) + FILEPATH.replace( /[^/]+/g, ".." ) + "/" :
 "../",
 QUnit = window.QUnit,
-require = window.require,
+require = window.require;
+
+function getQUnitConfig() {
+var config = Object.create( null );
 
 // Default to unminified jQuery for directly-opened iframes
-config = QUnit ?
+if ( !QUnit ) {
+config.dev = true;
+} else {
 
 // QUnit.config is populated from QUnit.urlParams but only at the beginning
 // of the test run. We need to read both.
-{
-esmodules: !!( QUnit.config.esmodules || QUnit.urlParams.esmodules ),
-amd: !!( QUnit.config.amd || QUnit.urlParams.amd )
-} :
+QUnit.config.urlConfig.forEach( function( entry ) {
+config[ entry.id ] = QUnit.config[ entry.id ] != null ?
+QUnit.config[ entry.id ] :
+QUnit.urlParams[ entry.id ];
+} );
+}
 
-{ dev: true },
-src = config.dev ?
-"dist/jquery.js" :
-"dist/jquery.min.js";
+return config;
+}
 
 // Define configuration parameters controlling how jQuery is loaded
 if ( QUnit ) {
@@ -43,6 +48,12 @@
 } );
 }
 
+config = getQUnitConfig();
+
+src = config.dev ?
+"dist/jquery.js" :
+"dist/jquery.min.js";
+
 // Honor ES modules loading on the main window (detected by seeing QUnit on it).
 // This doesn't apply to iframes because they synchronously expect jQuery to be there.
 if ( config.esmodules && QUnit ) {