Merge pull request then#25 from calvinmetcalf/add-es6

fixes then#23 by adding resolve, reject, cast, race, and prototype.catch

Author: ForbesLindesay

index.js

@@ -32,7 +32,7 @@ var UNDEFINED = new ValuePromise(undefined)
 var ZERO = new ValuePromise(0)
 var EMPTYSTRING = new ValuePromise('')
 
-Promise.from = function (value) {
+Promise.from = Promise.cast = function (value) {
   if (value instanceof Promise) return value
 
   if (value === null) return NULL
@@ -131,6 +131,7 @@ Promise.prototype.done = function (onFulfilled, onRejected) {
     })
   })
 }
+
 Promise.prototype.nodeify = function (callback) {
   if (callback === null || typeof callback == 'undefined') return this
 
@@ -144,3 +145,28 @@ Promise.prototype.nodeify = function (callback) {
     })
   })
 }
+
+Promise.prototype.catch = function (onRejected) {
+  return this.then(null, onRejected);
+}
+
+
+Promise.resolve = function (value) {
+  return new Promise(function (resolve) { 
+    resolve(value);
+  });
+}
+
+Promise.reject = function (value) {
+  return new Promise(function (resolve, reject) { 
+    reject(value);
+  });
+}
+
+Promise.race = function (values) {
+  return new Promise(function (resolve, reject) { 
+    values.map(function(value){
+      Promise.cast(value).then(resolve, reject);
+    })
+  });
+}

test/adapter-a.js

@@ -1,22 +1,17 @@
 var Promise = require('../');
 
-module.exports = {
-  deferred: function () {
-    var resolve, reject;
-    var promise = new Promise(function (_resolve, _reject) {
-      resolve = _resolve;
-      reject = _reject;
-    });
-    return {
-      promise: promise,
-      resolve: resolve,
-      reject: reject
-    };
-  },
-  resolved: function (value) {
-    return Promise.from(value);
-  },
-  rejected: function (value) {
-    return new Promise(function (resolve, reject) { reject(value); });
-  }
-}
+
+exports.deferred = function () {
+  var resolve, reject;
+  var promise = new Promise(function (_resolve, _reject) {
+    resolve = _resolve;
+    reject = _reject;
+  });
+  return {
+    promise: promise,
+    resolve: resolve,
+    reject: reject
+  };
+};
+exports.resolved = Promise.resolve;
+exports.rejected = Promise.reject;

test/extensions-tests.js

@@ -25,11 +25,70 @@ describe('extensions', function () {
         assert(promise === Promise.from(promise))
       })
     })
+    describe('if passed a thenable', function () {
+      describe('using then', function () {
+        it('assimilates it', function (done) {
+          var i = 2
+          var promise = Promise.from(thenable)
+          var promiseRejected = Promise.from(thenableRejected)
+          assert(promise instanceof Promise)
+          assert(promiseRejected instanceof Promise)
+          promise.then(function (res) {
+            assert(res === sentinel)
+            if (0 === --i) done()
+          })
+          .then(null, done)
+          promiseRejected.then(null, function (err) {
+            assert(err === sentinel)
+            if (0 === --i) done()
+          })
+          .then(null, done)
+        })
+      })
+      describe('using catch', function () {
+        it('assimilates it', function (done) {
+          var i = 2
+          var promise = Promise.from(thenable)
+          var promiseRejected = Promise.from(thenableRejected)
+          assert(promise instanceof Promise)
+          assert(promiseRejected instanceof Promise)
+          promise.then(function (res) {
+            assert(res === sentinel)
+            if (0 === --i) done()
+          })
+          .catch(done)
+          promiseRejected.catch(function (err) {
+            assert(err === sentinel)
+            if (0 === --i) done()
+          })
+          .catch(done)
+        })
+      })
+    })
+    describe('if passed a value', function () {
+      it('wraps it in a promise', function (done) {
+        var promise = Promise.from(sentinel)
+          .then(function (res) {
+            assert(res === sentinel)
+            done()
+          })
+        assert(promise instanceof Promise)
+        assert(Promise.from(sentinel) instanceof Promise)
+        assert(Promise.from(sentinel).constructor === Promise)
+      })
+    })
+  })
+  describe('Promise.cast', function () {
+    describe('if passed a true promise', function () {
+      it('returns it directly', function () {
+        assert(promise === Promise.cast(promise))
+      })
+    })
     describe('if passed a thenable', function () {
       it('assimilates it', function (done) {
         var i = 2
-        var promise = Promise.from(thenable)
-        var promiseRejected = Promise.from(thenableRejected)
+        var promise = Promise.cast(thenable)
+        var promiseRejected = Promise.cast(thenableRejected)
         assert(promise instanceof Promise)
         assert(promiseRejected instanceof Promise)
         promise.then(function (res) {
@@ -46,14 +105,14 @@ describe('extensions', function () {
     })
     describe('if passed a value', function () {
       it('wraps it in a promise', function (done) {
-        var promise = Promise.from(sentinel)
+        var promise = Promise.cast(sentinel)
           .then(function (res) {
             assert(res === sentinel)
             done()
           })
         assert(promise instanceof Promise)
-        assert(Promise.from(sentinel) instanceof Promise)
-        assert(Promise.from(sentinel).constructor === Promise)
+        assert(Promise.cast(sentinel) instanceof Promise)
+        assert(Promise.cast(sentinel).constructor === Promise)
       })
     })
   })