Merge pull request #1095 from jtwebman/add-reflect

Add back reflect and reflectAll.

5 files changed, 248 insertions, 0 deletions

diff --git a/README.md b/README.md
index 3009118..79ced0a 100644
--- a/README.md
+++ b/README.md
@@ -264,6 +264,8 @@ Some functions are also available in the following forms:
 * [`dir`](#dir)
 * [`noConflict`](#noConflict)
 * [`timeout`](#timeout)
+* [`reflect`](#reflect)
+* [`reflectAll`](#reflectAll)
 
 ## Collections
 
@@ -2095,3 +2097,82 @@ async.timeout(function(callback) {
   doAsyncTask(callback);
 }, 1000);
 ```
+
+---------------------------------------
+
+<a name="reflect"></a>
+### reflect(function)
+
+Wraps the function in another function that always returns data even when it errors.
+The object returns ether has a property of error or value.
+
+__Arguments__
+
+* `function` - The function you want to wrap
+
+__Example__
+
+```js
+async.parallel([
+    async.reflect(function(callback){
+        // do some stuff ...
+        callback(null, 'one');
+    }),
+    async.reflect(function(callback){
+        // do some more stuff but error ...
+        callback('bad stuff happened');
+    }),
+    async.reflect(function(callback){
+        // do some more stuff ...
+        callback(null, 'two');
+    })
+],
+// optional callback
+function(err, results){
+  // values
+  // results[0].value = 'one'
+  // results[1].error = 'bad stuff happened'
+  // results[2].value = 'two'
+});
+```
+
+---------------------------------------
+
+<a name="reflectAll"></a>
+### reflectAll()
+
+A helper function that wraps an array of functions with reflect.
+
+__Arguments__
+
+* `tasks` - The array of functions to wrap in reflect.
+
+__Example__
+
+```javascript
+let tasks = [
+  function(callback){
+    setTimeout(function(){
+        callback(null, 'one');
+    }, 200);
+  },
+  function(callback){
+    // do some more stuff but error ...
+    callback(new Error('bad stuff happened'));
+  }
+  function(callback){
+    setTimeout(function(){
+      callback(null, 'two');
+    }, 100);
+  }
+];
+
+async.parallel(async.reflectAll(tasks),
+// optional callback
+function(err, results){
+  // values
+  // results[0].value = 'one'
+  // results[1].error = Error('bad stuff happened')
+  // results[2].value = 'two'
+});
+```
diff --git a/lib/index.js b/lib/index.js
index e3eb48d..6832662 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -47,7 +47,9 @@ import queue from './queue';
 import race from './race';
 import reduce from './reduce';
 import reduceRight from './reduceRight';
+import reflect from './reflect';
 import reject from './reject';
+import reflectAll from './reflectAll';
 import rejectLimit from './rejectLimit';
 import rejectSeries from './rejectSeries';
 import retry from './retry';
@@ -117,6 +119,8 @@ export default {
     race: race,
     reduce: reduce,
     reduceRight: reduceRight,
+    reflect: reflect,
+    reflectAll: reflectAll,
     reject: reject,
     rejectLimit: rejectLimit,
     rejectSeries: rejectSeries,
@@ -205,6 +209,8 @@ export {
     race as race,
     reduce as reduce,
     reduceRight as reduceRight,
+    reflect as reflect,
+    reflectAll as reflectAll,
     reject as reject,
     rejectLimit as rejectLimit,
     rejectSeries as rejectSeries,
diff --git a/lib/reflect.js b/lib/reflect.js
new file mode 100644
index 0000000..53cfa44
--- /dev/null
+++ b/lib/reflect.js
@@ -0,0 +1,29 @@
+'use strict';
+
+export default function reflect(fn) {
+    return function reflectOn() {
+        var args = Array.prototype.slice.call(arguments);
+        var reflectCallback = args.pop();
+
+        args.push(function callback(err) {
+            if (err) {
+                reflectCallback(null, {
+                    error: err
+                });
+            } else {
+                var cbArgs = Array.prototype.slice.call(arguments, 1);
+                var value = null;
+                if (cbArgs.length === 1) {
+                    value = cbArgs[0];
+                } else if (cbArgs.length > 1) {
+                    value = cbArgs;
+                }
+                reflectCallback(null, {
+                    value: value
+                });
+            }
+        });
+
+        return fn.apply(this, args);
+    };
+}
diff --git a/lib/reflectAll.js b/lib/reflectAll.js
new file mode 100644
index 0000000..c4ecd9f
--- /dev/null
+++ b/lib/reflectAll.js
@@ -0,0 +1,7 @@
+'use strict';
+
+import reflect from './reflect';
+
+export default function reflectAll(tasks) {
+    return tasks.map(reflect);
+}
diff --git a/test/test-async.js b/test/test-async.js
index 6e11b5a..6831ac2 100755
--- a/test/test-async.js
+++ b/test/test-async.js
@@ -491,6 +491,29 @@ exports['parallel call in another context'] = function(test) {
     vm.runInNewContext(fn, sandbox);
 };
 
+exports['parallel error with reflect'] = function(test){
+    async.parallel([
+        async.reflect(function(callback){
+            callback('error', 1);
+        }),
+        async.reflect(function(callback){
+            callback('error2', 2);
+        }),
+        async.reflect(function(callback){
+            callback(null, 2);
+        })
+    ],
+    function(err, results){
+        test.ok(err === null, err + " passed instead of 'null'");
+        test.same(results, [
+            { error: 'error' },
+            { error: 'error2' },
+            { value: 2 }
+        ]);
+        test.done();
+    });
+};
+
 exports['parallel does not continue replenishing after error'] = function (test) {
     var started = 0;
     var arr = [
@@ -558,6 +581,40 @@ exports['series'] = {
     });
 },
 
+    'with reflect': function(test){
+    var call_order = [];
+    async.series([
+        async.reflect(function(callback){
+            setTimeout(function(){
+                call_order.push(1);
+                callback(null, 1);
+            }, 25);
+        }),
+        async.reflect(function(callback){
+            setTimeout(function(){
+                call_order.push(2);
+                callback(null, 2);
+            }, 50);
+        }),
+        async.reflect(function(callback){
+            setTimeout(function(){
+                call_order.push(3);
+                callback(null, 3,3);
+            }, 15);
+        })
+    ],
+    function(err, results){
+        test.ok(err === null, err + " passed instead of 'null'");
+        test.deepEqual(results, [
+            { value: 1 },
+            { value: 2 },
+            { value: [3,3] }
+        ]);
+        test.same(call_order, [1,2,3]);
+        test.done();
+    });
+},
+
     'empty array': function(test){
     async.series([], function(err, results){
         test.equals(err, null);
@@ -583,6 +640,30 @@ exports['series'] = {
     setTimeout(test.done, 100);
 },
 
+    'error with reflect': function(test){
+    test.expect(2);
+    async.series([
+        async.reflect(function(callback){
+            callback('error', 1);
+        }),
+        async.reflect(function(callback){
+            callback('error2', 2);
+        }),
+        async.reflect(function(callback){
+            callback(null, 1);
+        })
+    ],
+    function(err, results){
+        test.ok(err === null, err + " passed instead of 'null'");
+        test.deepEqual(results, [
+            { error: 'error' },
+            { error: 'error2' },
+            { value: 1 }
+        ]);
+        test.done();
+    });
+},
+
     'no callback': function(test){
     async.series([
         function(callback){callback();},
@@ -1334,6 +1415,50 @@ exports['map'] = {
     });
 },
 
+    'with reflect': function(test){
+    var call_order = [];
+    async.map([1,3,2], async.reflect(function(item, cb) {
+        setTimeout(function(){
+            call_order.push(item);
+            cb(null, item*2);
+        }, item*25);
+    }), function(err, results){
+        test.ok(err === null, err + " passed instead of 'null'");
+        test.same(call_order, [1,2,3]);
+        test.same(results, [
+            { value: 2 },
+            { value: 6 },
+            { value: 4 }
+        ]);
+        test.done();
+    });
+},
+
+    'error with reflect': function(test){
+    var call_order = [];
+    async.map([-1,1,3,2], async.reflect(function(item, cb) {
+        setTimeout(function(){
+            call_order.push(item);
+            if (item < 0) {
+                cb('number less then zero');
+            } else {
+                cb(null, item*2);
+            }
+
+        }, item*25);
+    }), function(err, results){
+        test.ok(err === null, err + " passed instead of 'null'");
+        test.same(call_order, [-1,1,2,3]);
+        test.same(results, [
+            { error: 'number less then zero' },
+            { value: 2 },
+            { value: 6 },
+            { value: 4 }
+        ]);
+        test.done();
+    });
+},
+
     'map original untouched': function(test){
     var a = [1,2,3];
     async.map(a, function(x, callback){