Adds always and chain methods to deferreds.

src/deferred.js

@@ -1,7 +1,7 @@
 (function( jQuery ) {
 
 var // Promise methods
-	promiseMethods = "then done fail isResolved isRejected promise".split( " " ),
+	promiseMethods = "done fail isResolved isRejected promise then always chain".split( " " ),
 	// Static reference to slice
 	sliceDeferred = [].slice;
 
@@ -100,10 +100,38 @@ jQuery.extend({
 				deferred.done( doneCallbacks ).fail( failCallbacks );
 				return this;
 			},
+			always: function() {
+				return deferred.done.apply( deferred, arguments ).fail.apply( this, arguments );
+			},
 			fail: failDeferred.done,
 			rejectWith: failDeferred.resolveWith,
 			reject: failDeferred.resolve,
 			isRejected: failDeferred.isResolved,
+			// Chain
+			chain: function( fnDone, fnFail ) {
+				return jQuery.Deferred(function( newDefer ) {
+					jQuery.each( {
+						done: [ fnDone, "resolve" ],
+						fail: [ fnFail, "reject" ]
+					}, function( handler, data ) {
+						var fn = data[ 0 ],
+							action = data[ 1 ],
+							returned;
+						if ( jQuery.isFunction( fn ) ) {
+							deferred[ handler ](function() {
+								returned = fn.apply( this, arguments );
+								if ( jQuery.isFunction( returned.promise ) ) {
+									returned.promise().then( newDefer.resolve, newDefer.reject );
+								} else {
+									newDefer[ action ]( returned );
+								}
+							});
+						} else {
+							deferred[ handler ]( newDefer[ action ] );
+						}
+					} );
+				}).promise();
+			},
 			// Get a promise for this deferred
 			// If obj is provided, the promise aspect is added to the object
 			promise: function( obj ) {

test/unit/deferred.js

@@ -1,6 +1,12 @@
 module("deferred", { teardown: moduleTeardown });
 
-test("jQuery._Deferred()", function() {
+jQuery.each( [ "", " - new operator" ], function( _, withNew ) {
+
+	function createDeferred() {
+		return withNew ? new jQuery._Deferred() : jQuery._Deferred();
+	}
+
+	test("jQuery._Deferred" + withNew, function() {
 
 		expect( 11 );
 
@@ -8,7 +14,7 @@ test("jQuery._Deferred()", function() {
 			object,
 			test;
 
-	deferred = jQuery._Deferred();
+		deferred = createDeferred();
 
 		test = false;
 
@@ -41,7 +47,7 @@ test("jQuery._Deferred()", function() {
 
 		ok( test , "Test cancel" );
 
-	deferred = jQuery._Deferred().resolve();
+		deferred = createDeferred().resolve();
 
 		try {
 			deferred.done( function() {
@@ -55,7 +61,7 @@ test("jQuery._Deferred()", function() {
 		}
 
 		test = "";
-	deferred = jQuery._Deferred().done( function() {
+		deferred = createDeferred().done( function() {
 
 			test += "A";
 
@@ -86,68 +92,182 @@ test("jQuery._Deferred()", function() {
 
 		strictEqual( test , "ABC" , "Test done callbacks order" );
 
-	deferred = jQuery._Deferred();
+		deferred = createDeferred();
 
 		deferred.resolveWith( jQuery , [ document ] ).done( function( doc ) {
 			ok( this === jQuery && arguments.length === 1 && doc === document , "Test fire context & args" );
 		});
 
 		// #8421
-	deferred = jQuery._Deferred();
+		deferred = createDeferred();
 		deferred.resolveWith().done(function() {
 			ok( true, "Test resolveWith can be called with no argument" );
 		});
 	});
+} );
 
-test("jQuery.Deferred()", function() {
+jQuery.each( [ "", " - new operator" ], function( _, withNew ) {
 
-	expect( 10 );
+	function createDeferred( fn ) {
+		return withNew ? new jQuery.Deferred( fn ) : jQuery.Deferred( fn );
+	}
 
-	jQuery.Deferred( function( defer ) {
+	test("jQuery.Deferred" + withNew, function() {
-		strictEqual( this , defer , "Defer passed as this & first argument" );
+
+		expect( 8 );
+
+		createDeferred().resolve().then( function() {
+			ok( true , "Success on resolve" );
+			ok( this.isResolved(), "Deferred is resolved" );
+		}, function() {
+			ok( false , "Error on resolve" );
+		}).always( function() {
+			ok( true , "Always callback on resolve" );
+		});
+
+		createDeferred().reject().then( function() {
+			ok( false , "Success on reject" );
+		}, function() {
+			ok( true , "Error on reject" );
+			ok( this.isRejected(), "Deferred is rejected" );
+		}).always( function() {
+			ok( true , "Always callback on reject" );
+		});
+
+		createDeferred( function( defer ) {
+			ok( this === defer , "Defer passed as this & first argument" );
 			this.resolve( "done" );
 		}).then( function( value ) {
 			strictEqual( value , "done" , "Passed function executed" );
 		});
-
+	});
-	jQuery.Deferred().resolve().then( function() {
-		ok( true , "Success on resolve" );
-	}, function() {
-		ok( false , "Error on resolve" );
 } );
 
-	jQuery.Deferred().reject().then( function() {
+test( "jQuery.Deferred.chain - filtering (done)", function() {
-		ok( false , "Success on reject" );
+
-	}, function() {
+	expect(3);
-		ok( true , "Error on reject" );
+
+	var defer = jQuery.Deferred(),
+		chained = defer.chain(function( a, b ) {
+			return a * b;
+		}),
+		value1,
+		value2,
+		value3;
+
+	chained.done(function( result ) {
+		value3 = result;
 	});
 
-	( new jQuery.Deferred( function( defer ) {
+	defer.done(function( a, b ) {
-		strictEqual( this , defer , "Defer passed as this & first argument (new)" );
+		value1 = a;
-		this.resolve( "done" );
+		value2 = b;
-	}) ).then( function( value ) {
-		strictEqual( value , "done" , "Passed function executed (new)" );
 	});
 
-	( new jQuery.Deferred() ).resolve().then( function() {
+	defer.resolve( 2, 3 );
-		ok( true , "Success on resolve (new)" );
+
-	}, function() {
+	strictEqual( value1, 2, "first resolve value ok" );
-		ok( false , "Error on resolve (new)" );
+	strictEqual( value2, 3, "second resolve value ok" );
+	strictEqual( value3, 6, "result of filter ok" );
+
+	jQuery.Deferred().reject().chain(function() {
+		ok( false, "chain should not be called on reject" );
+	});
 });
 
-	( new jQuery.Deferred() ).reject().then( function() {
+test( "jQuery.Deferred.chain - filtering (fail)", function() {
-		ok( false , "Success on reject (new)" );
+
-	}, function() {
+	expect(3);
-		ok( true , "Error on reject (new)" );
+
+	var defer = jQuery.Deferred(),
+		chained = defer.chain( null, function( a, b ) {
+			return a * b;
+		} ),
+		value1,
+		value2,
+		value3;
+
+	chained.fail(function( result ) {
+		value3 = result;
 	});
 
-	var tmp = jQuery.Deferred();
+	defer.fail(function( a, b ) {
-
+		value1 = a;
-	strictEqual( tmp.promise() , tmp.promise() , "Test deferred always return same promise" );
+		value2 = b;
-	strictEqual( tmp.promise() , tmp.promise().promise() , "Test deferred's promise always return same promise as deferred" );
 	});
 
-test("jQuery.when()", function() {
+	defer.reject( 2, 3 );
+
+	strictEqual( value1, 2, "first reject value ok" );
+	strictEqual( value2, 3, "second reject value ok" );
+	strictEqual( value3, 6, "result of filter ok" );
+
+	jQuery.Deferred().resolve().chain( null, function() {
+		ok( false, "chain should not be called on resolve" );
+	} );
+});
+
+test( "jQuery.Deferred.chain - deferred (done)", function() {
+
+	expect(3);
+
+	var defer = jQuery.Deferred(),
+		chained = defer.chain(function( a, b ) {
+			return jQuery.Deferred(function( defer ) {
+				defer.reject( a * b );
+			});
+		}),
+		value1,
+		value2,
+		value3;
+
+	chained.fail(function( result ) {
+		value3 = result;
+	});
+
+	defer.done(function( a, b ) {
+		value1 = a;
+		value2 = b;
+	});
+
+	defer.resolve( 2, 3 );
+
+	strictEqual( value1, 2, "first resolve value ok" );
+	strictEqual( value2, 3, "second resolve value ok" );
+	strictEqual( value3, 6, "result of filter ok" );
+});
+
+test( "jQuery.Deferred.chain - deferred (fail)", function() {
+
+	expect(3);
+
+	var defer = jQuery.Deferred(),
+		chained = defer.chain( null, function( a, b ) {
+			return jQuery.Deferred(function( defer ) {
+				defer.resolve( a * b );
+			});
+		} ),
+		value1,
+		value2,
+		value3;
+
+	chained.done(function( result ) {
+		value3 = result;
+	});
+
+	defer.fail(function( a, b ) {
+		value1 = a;
+		value2 = b;
+	});
+
+	defer.reject( 2, 3 );
+
+	strictEqual( value1, 2, "first reject value ok" );
+	strictEqual( value2, 3, "second reject value ok" );
+	strictEqual( value3, 6, "result of filter ok" );
+});
+
+test( "jQuery.when" , function() {
 
 	expect( 23 );
 
@@ -166,13 +286,13 @@ test("jQuery.when()", function() {
 
 	} , function( message , value ) {
 
-		ok( jQuery.isFunction( jQuery.when( value ).then( function( resolveValue ) {
+		ok( jQuery.isFunction( jQuery.when( value ).done(function( resolveValue ) {
 			strictEqual( resolveValue , value , "Test the promise was resolved with " + message );
 		}).promise ) , "Test " + message + " triggers the creation of a new Promise" );
 
 	} );
 
-	ok( jQuery.isFunction( jQuery.when().then( function( resolveValue ) {
+	ok( jQuery.isFunction( jQuery.when().done(function( resolveValue ) {
 		strictEqual( resolveValue , undefined , "Test the promise was resolved with no parameter" );
 	}).promise ) , "Test calling when with no parameter triggers the creation of a new Promise" );
 
@@ -181,42 +301,48 @@ test("jQuery.when()", function() {
 	for( i = 1 ; i < 4 ; i++ ) {
 		jQuery.when( cache || jQuery.Deferred( function() {
 			this.resolve( i );
-		}) ).then( function( value ) {
+		}) ).done(function( value ) {
 			strictEqual( value , 1 , "Function executed" + ( i > 1 ? " only once" : "" ) );
 			cache = value;
-		}, function() {
-			ok( false , "Fail called" );
 		});
 	}
 });
 
-test("jQuery.when() - joined", function() {
+test("jQuery.when - joined", function() {
 
-	expect(8);
+	expect(25);
 
-	jQuery.when( 1, 2, 3 ).done( function( a, b, c ) {
+	var deferreds = {
-		strictEqual( a , 1 , "Test first param is first resolved value - non-observables" );
+			value: 1,
-		strictEqual( b , 2 , "Test second param is second resolved value - non-observables" );
+			success: jQuery.Deferred().resolve( 1 ),
-		strictEqual( c , 3 , "Test third param is third resolved value - non-observables" );
+			error: jQuery.Deferred().reject( 0 ),
-	}).fail( function() {
+			futureSuccess: jQuery.Deferred(),
-		ok( false , "Test the created deferred was resolved - non-observables");
+			futureError: jQuery.Deferred()
-	});
+		},
+		willSucceed = {
+			value: true,
+			success: true,
+			error: false,
+			futureSuccess: true,
+			futureError: false
+		};
 
-	var successDeferred = jQuery.Deferred().resolve( 1 , 2 , 3 ),
+	jQuery.each( deferreds, function( id1, defer1 ) {
-		errorDeferred = jQuery.Deferred().reject( "error" , "errorParam" );
+		jQuery.each( deferreds, function( id2, defer2 ) {
-
+			var shouldResolve = willSucceed[ id1 ] && willSucceed[ id2 ],
-	jQuery.when( 1 , successDeferred , 3 ).done( function( a, b, c ) {
+				expected = shouldResolve ? [ 1, 1 ] : [ 0, undefined ],
-		strictEqual( a , 1 , "Test first param is first resolved value - resolved observable" );
+				code = id1 + "/" + id2;
-		same( b , [ 1 , 2 , 3 ] , "Test second param is second resolved value - resolved observable" );
+			jQuery.when( defer1, defer2 ).done(function( a, b ) {
-		strictEqual( c , 3 , "Test third param is third resolved value - resolved observable" );
+				if ( shouldResolve ) {
-	}).fail( function() {
+					same( [ a, b ], expected, code + " => resolve" );
-		ok( false , "Test the created deferred was resolved - resolved observable");
+				}
-	});
+			}).fail(function( a, b ) {
-
+				if ( !shouldResolve ) {
-	jQuery.when( 1 , errorDeferred , 3 ).done( function() {
+					same( [ a, b ], expected, code + " => resolve" );
-		ok( false , "Test the created deferred was rejected - rejected observable");
+				}
-	}).fail( function( error , errorParam ) {
-		strictEqual( error , "error" , "Test first param is first rejected value - rejected observable" );
-		strictEqual( errorParam , "errorParam" , "Test second param is second rejected value - rejected observable" );
 			});
 		} );
+	} );
+	deferreds.futureSuccess.resolve( 1 );
+	deferreds.futureError.reject( 0 );
+});