promise.prototype.finally - npm Package Compare versions

Comparing version 1.0.0 to 1.0.1

finally.js

@@ -8,25 +8,24 @@ /**
 
-// Get a handle on the global object
-var local;
-if (typeof global !== 'undefined') local = global;
-else if (typeof window !== 'undefined' && window.document) local = window;
-else local = self;
+(function() {
+	// Get a handle on the global object
+	var local;
+	if (typeof global !== 'undefined') local = global;
+	else if (typeof window !== 'undefined' && window.document) local = window;
+	else local = self;
 
-// Polyfill (verb)
-var finallySupport = "finally" in local.Promise.prototype;
-if (!finallySupport) local.Promise.prototype['finally'] = finallyPolyfill;
+	// It's replaced unconditionally to preserve the expected behavior
+	// in programs even if there's ever a native finally.
+	local.Promise.prototype['finally'] = function finallyPolyfill(callback) {
+		var constructor = this.constructor;
 
-// Polyfill (noun)
-function finallyPolyfill(callback) {
-	var constructor = this.constructor;
-
-	return this.then(function(value) {
-			return constructor.resolve(callback()).then(function() {
-				return value;
+		return this.then(function(value) {
+				return constructor.resolve(callback()).then(function() {
+					return value;
+				});
+			}, function(reason) {
+				return constructor.resolve(callback()).then(function() {
+					throw reason;
+				});
 			});
-		}, function(reason) {
-			return constructor.resolve(callback()).then(function() {
-				throw reason;
-			});
-		});
-}
+	};
+}());

package.json

 {
   "name": "promise.prototype.finally",
   "description": "A polyfill for Promise.prototype.finally for ES6 compliant promises",
-  "version": "1.0.0",
+  "version": "1.0.1",
   "scripts": {
@@ -6,0 +6,0 @@ "test": "npm run lintspaces && npm run jshint && ./node_modules/.bin/mocha test",

README.md

 # Promise.prototype.finally [ ![Codeship Status for matthew-andrews/Promise.prototype.finally](https://codeship.io/projects/d2ed45d0-3364-0132-3c6b-26237c03a86a/status)](https://codeship.io/projects/40589)
 
-A polyfill for `Promise.prototype.finally`.  See docs on what finally is on [your favourite pre-ES6 promise library](https://github.com/kriskowal/q/wiki/API-Reference#promisefinallycallback).
+A polyfill for `Promise.prototype.finally`.  See docs on what finally is on [your favourite pre-ES6 promise library](https://github.com/tildeio/rsvp.js/blob/master/README.md#finally).
 
@@ -36,2 +36,2 @@ Warning: This micro-library doesn't force you to use any particular Promise implementation by using whatever `Promise` has been defined as globally.  This is so that you may use any ES6 standard Promise compliant library - or, of course, native ES6 Promises.
 
-The lead developer of **Promise.prototype.finally** is [Matt Andrews](http://twitter.com/andrewsmatt) at FT with unwitting help and support from [Stefan Penner](https://twitter.com/stefanpenner). All open source code released by FT Labs is licenced under the MIT licence. We welcome comments, feedback and suggestions.  Please feel free to raise an issue or pull request.
+The lead developer of **Promise.prototype.finally** is [Matt Andrews](http://twitter.com/andrewsmatt) at FT, the code is based on [a snippet](https://github.com/domenic/promises-unwrapping/issues/18#issuecomment-57801572) by [Stefan Penner](https://twitter.com/stefanpenner) - used [with permission](https://twitter.com/stefanpenner/status/520904347073667072). All open source code released by FT Labs is licenced under the MIT licence. We welcome comments, feedback and suggestions.  Please feel free to raise an issue or pull request.

test/es6-promise.js

@@ -6,21 +6,156 @@ var assert = require('assert');
 
-describe('finally', function() {
-	it('is defined', function(done) {
-		assert('finally' in Promise.prototype);
-		done();
-	});
-	it('is called on resolve', function(done) {
-		Promise.resolve(3)
-			.finally(function(value) {
-				assert(value === undefined);
-				done();
+var o_create = Object.create || function(o, props) {
+	function F() {}
+	F.prototype = o;
+
+	if (typeof(props) === "object") {
+		for (var prop in props) {
+			if (props.hasOwnProperty((prop))) {
+				F[prop] = props[prop];
+			}
+		}
+	}
+	return new F();
+};
+
+describe("Promise.finally", function() {
+	describe("native finally behaviour", function() {
+		describe("no value is passed in", function() {
+			it("does not provide a value to the finally code", function(done) {
+				var fulfillmentValue = 1;
+				var promise = Promise.resolve(fulfillmentValue);
+
+				promise['finally'](function() {
+					assert.equal(arguments.length, 0);
+					done();
+				});
 			});
-	});
-	it('is called on reject', function(done) {
-		Promise.reject(3)
-			.finally(function(value) {
-				assert(value === undefined);
-				done();
+
+			it("does not provide a reason to the finally code", function(done) {
+				var rejectionReason = new Error();
+				var promise = Promise.reject(rejectionReason);
+
+				promise['finally'](function(arg) {
+					assert.equal(arguments.length, 0);
+					done();
+				});
 			});
+		});
+
+		describe("non-exceptional cases do not affect the result", function(){
+			it("preserves the original fulfillment value even if the finally callback returns a value", function(done) {
+				var fulfillmentValue = 1;
+				var promise = Promise.resolve(fulfillmentValue);
+
+				promise['finally'](function() {
+					return 2;
+				}).then(function(value) {
+					assert.equal(fulfillmentValue, value);
+					done();
+				});
+			});
+
+			it("preserves the original rejection reason even if the finally callback returns a value", function(done) {
+				var rejectionReason = new Error();
+				var promise = Promise.reject(rejectionReason);
+
+				promise['finally'](function() {
+					return 2;
+				}).then(undefined, function(reason) {
+					assert.equal(rejectionReason, reason);
+					done();
+				});
+			});
+		});
+
+		describe("exception cases do propogate the failure", function(){
+			describe("fulfilled promise", function(){
+				it("propagates changes via throw", function(done) {
+					var promise = Promise.resolve(1);
+					var expectedReason = new Error();
+
+					promise['finally'](function() {
+						throw expectedReason;
+					}).then(undefined, function(reason) {
+						assert.deepEqual(expectedReason, reason);
+						done();
+					});
+				});
+
+				it("propagates changes via returned rejected promise", function(done){
+					var promise = Promise.resolve(1);
+					var expectedReason = new Error();
+
+					promise['finally'](function() {
+						return Promise.reject(expectedReason);
+					}).then(undefined, function(reason) {
+						assert.deepEqual(expectedReason, reason);
+						done();
+					});
+				});
+			});
+
+			describe("rejected promise", function(){
+				it("propagates changes via throw", function(done) {
+					var promise = Promise.reject(1);
+					var expectedReason = new Error();
+
+					promise['finally'](function() {
+						throw expectedReason;
+					}).then(undefined, function(reason) {
+						assert.deepEqual(expectedReason, reason);
+						done();
+					});
+				});
+
+				it("propagates changes via returned rejected promise", function(done){
+					var promise = Promise.reject(1);
+					var expectedReason = new Error();
+
+					promise['finally'](function() {
+						return Promise.reject(expectedReason);
+					}).then(undefined, function(reason) {
+						assert.deepEqual(expectedReason, reason);
+						done();
+					});
+				});
+			});
+
+			describe("inheritance", function() {
+				function Subclass (resolver) {
+					this._promise$constructor(resolver);
+				}
+
+				Subclass.prototype = o_create(Promise.prototype);
+				Subclass.prototype.constructor = Subclass;
+				Subclass.prototype._promise$constructor = Promise;
+
+				Subclass.resolve = Promise.resolve;
+				Subclass.reject = Promise.reject;
+				Subclass.all = Promise.all;
+
+				it("preserves correct subclass when chained", function() {
+					var promise = Subclass.resolve().finally();
+					assert.ok(promise instanceof Subclass);
+					assert.equal(promise.constructor, Subclass);
+				});
+
+				it("preserves correct subclass when rejected", function() {
+					var promise = Subclass.resolve().finally(function() {
+						throw new Error("OMG");
+					});
+					assert.ok(promise instanceof Subclass);
+					assert.equal(promise.constructor, Subclass);
+				});
+
+				it("preserves correct subclass when someone returns a thenable", function() {
+					var promise = Subclass.resolve().finally(function() {
+						return Promise.resolve(1);
+					});
+					assert.ok(promise instanceof Subclass);
+					assert.equal(promise.constructor, Subclass);
+				});
+			});
+		});
 	});
 });

No alert changes

Improved metrics

Total package byte prevSize

8458

increased by98.13%

Lines of code

162

increased by224%

No dependency changes