Add _.unzip. [closes #225]

Former-commit-id: 4b2c7fc068fd430f3d78de850a5f7670fd0e1a4e

test/test-build.js

@@ -118,6 +118,7 @@
     'union',
     'uniq',
     'unique',
+    'unzip',
     'without',
     'zip',
     'zipObject'
@@ -296,8 +297,8 @@
     'without'
   ];
 
-  /** List of methods used by Underscore */
-  var underscoreMethods = _.without.apply(_, [allMethods].concat([
+  /** List of Lo-Dash only methods */
+  var lodashOnlyMethods = [
     'at',
     'bindKey',
     'cloneDeep',
@@ -310,8 +311,12 @@
     'merge',
     'parseInt',
     'partialRight',
-    'runInContext'
-  ]));
+    'runInContext',
+    'unzip'
+  ];
+
+  /** List of methods used by Underscore */
+  var underscoreMethods = _.without.apply(_, [allMethods].concat(lodashOnlyMethods));
 
   /*--------------------------------------------------------------------------*/
 
@@ -970,22 +975,7 @@
         vm.runInContext(data.source, context);
         var lodash = context._;
 
-        _.each([
-          'assign',
-          'at',
-          'bindKey',
-          'createCallback',
-          'findIndex',
-          'findKey',
-          'forIn',
-          'forOwn',
-          'isPlainObject',
-          'merge',
-          'parseInt',
-          'partialRight',
-          'runInContext',
-          'zipObject'
-        ], function(methodName) {
+        _.each(lodashOnlyMethods.concat('assign'), function(methodName) {
           equal(lodash[methodName], undefined, '_.' + methodName + ' should not exist: ' + basename);
         });
 

test/test.js

@@ -2787,6 +2787,58 @@
 
   /*--------------------------------------------------------------------------*/
 
+  QUnit.module('lodash.unzip');
+
+  (function() {
+    var object = {
+      'an empty array': [
+        [],
+        []
+      ],
+      '0-tuples': [
+        [[], []],
+        []
+      ],
+      '1-tuples': [
+        [['moe'], ['larry']],
+        [['moe', 'larry']]
+      ],
+      '2-tuples': [
+        [['moe', 30], ['larry', 40]],
+        [['moe', 'larry'], [30, 40]]
+      ],
+      '3-tuples': [
+        [['moe', 30, true], ['larry', 40, false]],
+        [['moe', 'larry'], [30, 40], [true, false]]
+      ]
+    };
+
+    _.forOwn(object, function(pair, key) {
+      test('should work with ' + key, function() {
+        var actual = _.unzip(pair[0]);
+        deepEqual(actual, pair[1]);
+        deepEqual(_.zip.apply(_, actual), pair[1].length ? pair[0] : pair[1]);
+      });
+    });
+
+    test('should work with tuples of different lengths', function() {
+      var pair = [
+        [['moe', 30], ['larry', 40, false]],
+        [['moe', 'larry'], [30, 40], [undefined, false]]
+      ];
+
+      var actual = _.unzip(pair[0]);
+      ok(1 in actual);
+      deepEqual(actual, pair[1]);
+
+      actual = _.zip.apply(_, actual);
+      ok(2 in actual[0]);
+      deepEqual(actual, [['moe', 30, undefined], ['larry', 40, false]]);
+    });
+  }());
+
+  /*--------------------------------------------------------------------------*/
+
   QUnit.module('lodash.where');
 
   (function() {