Merge pull request #115 from braker1nine/when_return_array

Make sure `when` argument corresponds with `then` arguments

Author: andrewimm

src/ParsePromise.js

@@ -346,7 +346,8 @@ export default class ParsePromise {
    */
   static when(promises) {
     var objects;
-    if (Array.isArray(promises)) {
+    var arrayArgument = Array.isArray(promises);
+    if (arrayArgument) {
       objects = promises;
     } else {
       objects = arguments;
@@ -355,12 +356,13 @@ export default class ParsePromise {
     var total = objects.length;
     var hadError = false;
     var results = [];
+    var returnValue = arrayArgument ? [results] : results;
     var errors = [];
     results.length = objects.length;
     errors.length = objects.length;
 
     if (total === 0) {
-      return ParsePromise.as.apply(this, results);
+      return ParsePromise.as.apply(this, returnValue);
     }
 
     var promise = new ParsePromise();
@@ -371,7 +373,7 @@ export default class ParsePromise {
         if (hadError) {
           promise.reject(errors);
         } else {
-          promise.resolve.apply(promise, results);
+          promise.resolve.apply(promise, returnValue);
         }
       }
     };

src/__tests__/ParsePromise-test.js

@@ -227,7 +227,7 @@ describe('Promise', () => {
     jest.runAllTimers();
   }));
 
-  it('can handle promises in parallel', asyncHelper(function(done) {
+  it('can handle promises in parallel with array', asyncHelper(function(done) {
     var COUNT = 5;
 
     var delay = function(ms) {
@@ -249,7 +249,42 @@ describe('Promise', () => {
       generate(i);
     }
 
-    ParsePromise.when(promises).then(function() {
+    ParsePromise.when(promises).then(function(results) {
+      expect(called).toBe(COUNT);
+      expect(COUNT).toBe(results.length);
+      var actual = results;
+      for (var i = 0; i < actual.length; i++) {
+        expect(actual[i]).toBe(5 * i);
+      }
+      done();
+    });
+
+    jest.runAllTimers();
+  }));
+
+  it('can handle promises in parallel with arguments', asyncHelper(function(done) {
+    var COUNT = 5;
+
+    var delay = function(ms) {
+      var promise = new ParsePromise();
+      setTimeout(() => { promise.resolve(); }, ms);
+      return promise;
+    };
+
+    var called = 0;
+    var promises = [];
+    function generate(i) {
+      promises[i] = delay((i % 2) ? (i * 10) : (COUNT * 10) - (i * 10)).then(
+        function() {
+          called++;
+          return 5 * i;
+        });
+    }
+    for (var i = 0; i < COUNT; i++) {
+      generate(i);
+    }
+
+    ParsePromise.when.apply(null, promises).then(function() {
       expect(called).toBe(COUNT);
       expect(COUNT).toBe(arguments.length);
       var actual = arguments;