Added better catch definitions that pass through the original promise type or type union of promise|rejection type

bluebird/bluebird-tests.ts

@@ -80,6 +80,7 @@ var voidProm: Promise<void>;
 
 var fooProm: Promise<Foo>;
 var barProm: Promise<Bar>;
+var fooOrBarProm: Promise<Foo|Bar>;
 var bazProm: Promise<Baz>;
 
 // - - - - - - - - - - - - - - - - -
@@ -237,36 +238,96 @@ barProm = barProm.then((value: Bar) => {
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
-barProm = fooProm.catch((reason: any) => {
+fooProm = fooProm.catch((reason: any) => {
+	return;
+});
+
+fooProm = fooProm.caught((reason: any) => {
+	return;
+});
+fooProm = fooProm.catch((error: any) => {
+	return true;
+}, (reason: any) => {
+	return;
+});
+fooProm = fooProm.caught((error: any) => {
+	return true;
+}, (reason: any) => {
+	return;
+});
+
+fooProm = fooProm.catch((reason: any) => {
+	return voidProm;
+});
+
+fooProm = fooProm.caught((reason: any) => {
+	return voidProm;
+});
+fooProm = fooProm.catch((error: any) => {
+	return true;
+}, (reason: any) => {
+	return voidProm;
+});
+fooProm = fooProm.caught((error: any) => {
+	return true;
+}, (reason: any) => {
+	return voidProm;
+});
+
+fooProm = fooProm.catch((reason: any) => {
+	//handle multiple valid return types simultaneously
+	if (true) {
+		return;
+	} else if (false) {
+		return voidProm;
+	} else if (foo) {
+		return foo;
+	}
+});
+
+fooOrBarProm = fooProm.catch((reason: any) => {
 	return bar;
 });
-barProm = fooProm.caught((reason: any) => {
+fooOrBarProm = fooProm.caught((reason: any) => {
 	return bar;
 });
 
-barProm = fooProm.catch((reason: any) => {
-	return bar;
+fooOrBarProm = fooProm.catch((error: any) => {
+	return true;
 }, (reason: any) => {
 	return bar;
 });
-barProm = fooProm.caught((reason: any) => {
-	return bar;
+fooOrBarProm = fooProm.caught((error: any) => {
+	return true;
 }, (reason: any) => {
 	return bar;
 });
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
-barProm = fooProm.catch(Error, (reason: any) => {
+fooProm = fooProm.catch(Error, (reason: any) => {
+	return;
+});
+fooProm = fooProm.catch(Promise.CancellationError, (reason: any) => {
+	return;
+});
+fooProm = fooProm.caught(Error, (reason: any) => {
+	return;
+});
+fooProm = fooProm.caught(Promise.CancellationError, (reason: any) => {
+	return;
+});
+
+fooOrBarProm = fooProm.catch(Error, (reason: any) => {
 	return bar;
 });
-barProm = fooProm.catch(Promise.CancellationError, (reason: any) => {
+fooOrBarProm = fooProm.catch(Promise.CancellationError, (reason: any) => {
 	return bar;
 });
-barProm = fooProm.caught(Error, (reason: any) => {
+fooOrBarProm = fooProm.caught(Error, (reason: any) => {
 	return bar;
 });
-barProm = fooProm.caught(Promise.CancellationError, (reason: any) => {
+fooOrBarProm = fooProm.caught(Promise.CancellationError, (reason: any) => {
 	return bar;
 });
 

bluebird/bluebird.d.ts

@@ -33,11 +33,11 @@ declare class Promise<R> implements Promise.Thenable<R>, Promise.Inspection<R> {
 	 *
 	 * Alias `.caught();` for compatibility with earlier ECMAScript version.
 	 */
-	catch<U>(onReject?: (error: any) => Promise.Thenable<U>): Promise<U>;
-	caught<U>(onReject?: (error: any) => Promise.Thenable<U>): Promise<U>;
+	catch(onReject?: (error: any) => R|Promise.Thenable<R>|void|Promise.Thenable<void>): Promise<R>;
+	caught(onReject?: (error: any) => R|Promise.Thenable<R>|void|Promise.Thenable<void>): Promise<R>;
 
-	catch<U>(onReject?: (error: any) => U): Promise<U>;
-	caught<U>(onReject?: (error: any) => U): Promise<U>;
+	catch<U>(onReject?: (error: any) => U|Promise.Thenable<U>): Promise<U|R>;
+	caught<U>(onReject?: (error: any) => U|Promise.Thenable<U>): Promise<U|R>;
 
 	/**
 	 * This extends `.catch` to work more like catch-clauses in languages like Java or C#. Instead of manually checking `instanceof` or `.name === "SomeError"`, you may specify a number of error constructors which are eligible for this catch handler. The catch handler that is first met that has eligible constructors specified, is the one that will be called.
@@ -46,17 +46,18 @@ declare class Promise<R> implements Promise.Thenable<R>, Promise.Inspection<R> {
 	 *
 	 * Alias `.caught();` for compatibility with earlier ECMAScript version.
 	 */
-	catch<U>(predicate: (error: any) => boolean, onReject: (error: any) => Promise.Thenable<U>): Promise<U>;
-	caught<U>(predicate: (error: any) => boolean, onReject: (error: any) => Promise.Thenable<U>): Promise<U>;
+	catch(predicate: (error: any) => boolean, onReject: (error: any) => R|Promise.Thenable<R>|void|Promise.Thenable<void>): Promise<R>;
+	caught(predicate: (error: any) => boolean, onReject: (error: any) => R|Promise.Thenable<R>|void|Promise.Thenable<void>): Promise<R>;
 
-	catch<U>(predicate: (error: any) => boolean, onReject: (error: any) => U): Promise<U>;
-	caught<U>(predicate: (error: any) => boolean, onReject: (error: any) => U): Promise<U>;
+	catch<U>(predicate: (error: any) => boolean, onReject: (error: any) => U|Promise.Thenable<U>): Promise<U|R>;
+	caught<U>(predicate: (error: any) => boolean, onReject: (error: any) => U|Promise.Thenable<U>): Promise<U|R>;
 
-	catch<U>(ErrorClass: Function, onReject: (error: any) => Promise.Thenable<U>): Promise<U>;
-	caught<U>(ErrorClass: Function, onReject: (error: any) => Promise.Thenable<U>): Promise<U>;
+	catch(ErrorClass: Function, onReject: (error: any) => R|Promise.Thenable<R>|void|Promise.Thenable<void>): Promise<R>;
+	caught(ErrorClass: Function, onReject: (error: any) => R|Promise.Thenable<R>|void|Promise.Thenable<void>): Promise<R>;
+
+	catch<U>(ErrorClass: Function, onReject: (error: any) => U|Promise.Thenable<U>): Promise<U|R>;
+	caught<U>(ErrorClass: Function, onReject: (error: any) => U|Promise.Thenable<U>): Promise<U|R>;
 
-	catch<U>(ErrorClass: Function, onReject: (error: any) => U): Promise<U>;
-	caught<U>(ErrorClass: Function, onReject: (error: any) => U): Promise<U>;
 
 	/**
 	 * Like `.catch` but instead of catching all types of exceptions, it only catches those that don't originate from thrown errors but rather from explicit rejections.