From 7e2e2db806f621c61851bc9df32e398a5a6d345e Mon Sep 17 00:00:00 2001
From: Timo Tijhof <krinklemail@gmail.com>
Date: Thu, 17 Nov 2016 12:59:09 -0800
Subject: [PATCH] mw.loader: For using() errors, reject Promise instead of
 throwing

The "Unknown module" and "Circular dependency" errors both come from the
resolve() function. Add a try/catch around that and reject the promise
if caught.

Bug: T131612
Change-Id: I900909cd00df6a51f3bf1f3df91bdb610c11c446
---
 resources/src/mediawiki/mediawiki.js          |  9 +++-
 .../mediawiki/mediawiki.loader.test.js        | 53 +++++++++++++++----
 2 files changed, 49 insertions(+), 13 deletions(-)

diff --git a/resources/src/mediawiki/mediawiki.js b/resources/src/mediawiki/mediawiki.js
index 4dce192cf3..dd3d6dee64 100644
--- a/resources/src/mediawiki/mediawiki.js
+++ b/resources/src/mediawiki/mediawiki.js
@@ -1168,6 +1168,7 @@
 			 * @private
 			 * @param {string[]} modules Array of string module names
 			 * @return {Array} List of dependencies, including 'module'.
+			 * @throws {Error} If an unregistered module or a dependency loop is encountered
 			 */
 			function resolve( modules ) {
 				var resolved = [];
@@ -1993,8 +1994,12 @@
 						deferred.fail( error );
 					}
 
-					// Resolve entire dependency map
-					dependencies = resolve( dependencies );
+					try {
+						// Resolve entire dependency map
+						dependencies = resolve( dependencies );
+					} catch ( e ) {
+						return deferred.reject( e ).promise();
+					}
 					if ( allReady( dependencies ) ) {
 						// Run ready immediately
 						deferred.resolve( mw.loader.require );
diff --git a/tests/qunit/suites/resources/mediawiki/mediawiki.loader.test.js b/tests/qunit/suites/resources/mediawiki/mediawiki.loader.test.js
index 505d9a17fb..92d13260e9 100644
--- a/tests/qunit/suites/resources/mediawiki/mediawiki.loader.test.js
+++ b/tests/qunit/suites/resources/mediawiki/mediawiki.loader.test.js
@@ -134,6 +134,48 @@
 		} );
 	} );
 
+	QUnit.test( '.using() Error: Circular dependency', function ( assert ) {
+		mw.loader.register( [
+			[ 'test.circle1', '0', [ 'test.circle2' ] ],
+			[ 'test.circle2', '0', [ 'test.circle3' ] ],
+			[ 'test.circle3', '0', [ 'test.circle1' ] ]
+		] );
+		mw.loader.using( 'test.circle3' ).then(
+			function done() {
+				assert.ok( false, 'Unexpected resolution, expected error.' );
+			},
+			function fail( e ) {
+				assert.ok( /Circular/.test( String( e ) ), 'Detect circular dependency' );
+			}
+		);
+	} );
+
+	QUnit.test( '.load() - Error: Circular dependency', function ( assert ) {
+		mw.loader.register( [
+			[ 'test.circleA', '0', [ 'test.circleB' ] ],
+			[ 'test.circleB', '0', [ 'test.circleC' ] ],
+			[ 'test.circleC', '0', [ 'test.circleA' ] ]
+		] );
+		assert.throws( function () {
+			mw.loader.load( 'test.circleC' );
+		}, /Circular/, 'Detect circular dependency' );
+	} );
+
+	QUnit.test( '.using() - Error: Unregistered', function ( assert ) {
+		mw.loader.using( 'test.using.unreg' ).then(
+			function done() {
+				assert.ok( false, 'Unexpected resolution, expected error.' );
+			},
+			function fail( e ) {
+				assert.ok( /Unknown/.test( String( e ) ), 'Detect unknown dependency' );
+			}
+		);
+	} );
+
+	QUnit.test( '.load() - Error: Unregistered (ignored)', 0, function ( assert ) {
+		mw.loader.load( 'test.using.unreg2' );
+	} );
+
 	QUnit.test( '.implement( styles={ "css": [text, ..] } )', 2, function ( assert ) {
 		var $element = $( '<div class="mw-test-implement-a"></div>' ).appendTo( '#qunit-fixture' );
 
@@ -420,17 +462,6 @@
 		assert.strictEqual( mw.track.callCount, 1 );
 	} );
 
-	QUnit.test( 'Circular dependency', 1, function ( assert ) {
-		mw.loader.register( [
-			[ 'test.circle1', '0', [ 'test.circle2' ] ],
-			[ 'test.circle2', '0', [ 'test.circle3' ] ],
-			[ 'test.circle3', '0', [ 'test.circle1' ] ]
-		] );
-		assert.throws( function () {
-			mw.loader.using( 'test.circle3' );
-		}, /Circular/, 'Detect circular dependency' );
-	} );
-
 	QUnit.test( 'Out-of-order implementation', 9, function ( assert ) {
 		mw.loader.register( [
 			[ 'test.module4', '0' ],
-- 
2.20.1