Deferred: Stop inventing jQuery.when() resolution values

gibson042 · web-flow · commit 5d79c6466386 · 2016-12-16T11:45:35.000-05:00
Fixes gh-3442 Closes gh-3445
diff --git a/src/deferred.js b/src/deferred.js
@@ -13,7 +13,7 @@ function Thrower( ex ) {
 	throw ex;
 }
 
-function adoptValue( value, resolve, reject ) {
+function adoptValue( value, resolve, reject, noValue ) {
 	var method;
 
 	try {
@@ -29,9 +29,10 @@ function adoptValue( value, resolve, reject ) {
 		// Other non-thenables
 		} else {
 
-			// Support: Android 4.0 only
-			// Strict mode functions invoked without .call/.apply get global-object context
-			resolve.call( undefined, value );
+			// Control `resolve` arguments by letting Array#slice cast boolean `noValue` to integer:
+			// * false: [ value ].slice( 0 ) => resolve( value )
+			// * true: [ value ].slice( 1 ) => resolve()
+			resolve.apply( undefined, [ value ].slice( noValue ) );
 		}
 
 	// For Promises/A+, convert exceptions into rejections
@@ -41,7 +42,7 @@ function adoptValue( value, resolve, reject ) {
 
 		// Support: Android 4.0 only
 		// Strict mode functions invoked without .call/.apply get global-object context
-		reject.call( undefined, value );
+		reject.apply( undefined, [ value ] );
 	}
 }
 
@@ -366,7 +367,8 @@ jQuery.extend( {
 
 		// Single- and empty arguments are adopted like Promise.resolve
 		if ( remaining <= 1 ) {
-			adoptValue( singleValue, master.done( updateFunc( i ) ).resolve, master.reject );
+			adoptValue( singleValue, master.done( updateFunc( i ) ).resolve, master.reject,
+				!remaining );
 
 			// Use .then() to unwrap secondary thenables (cf. gh-3000)
 			if ( master.state() === "pending" ||
diff --git a/test/unit/deferred.js b/test/unit/deferred.js
@@ -814,11 +814,11 @@ QUnit.test( "jQuery.when(nonThenable) - like Promise.resolve", function( assert
 
 	jQuery.when()
 		.done( function( resolveValue ) {
-			assert.strictEqual( resolveValue, undefined, "Resolved .done with no arguments" );
+			assert.strictEqual( arguments.length, 0, "Resolved .done with no arguments" );
 			assert.strictEqual( this, defaultContext, "Default .done context with no arguments" );
 		} )
 		.then( function( resolveValue ) {
-			assert.strictEqual( resolveValue, undefined, "Resolved .then with no arguments" );
+			assert.strictEqual( arguments.length, 0, "Resolved .then with no arguments" );
 			assert.strictEqual( this, defaultContext, "Default .then context with no arguments" );
 		} );
 
