2676

modules/_findkeys.js

@@ -0,0 +1,16 @@
+import cb from './_cb.js';
+import keys from './keys.js';
+
+
+function findKeys(obj, predicate, context) {
+  predicate = cb(predicate, context);
+  var _keys = keys(obj), key;
+  var arr = [];
+  for (var i = 0, length = _keys.length; i < length; i++) {
+    key = _keys[i];
+    if (predicate(obj[key], key, obj)) {
+        arr.push(key);
+    }
+  }
+  return arr;
+}

modules/index.js

@@ -87,6 +87,7 @@ export { default as result } from './result.js';
 export { default as uniqueId } from './uniqueId.js';
 export { default as chain } from './chain.js';
 export { default as iteratee } from './iteratee.js';
+export { default as transition} from './transition'
 
 // Function (ahem) Functions
 // -------------------------

modules/transition.js

@@ -0,0 +1,33 @@
+export default function getTogglingfunction() {
+    if (arguments.length == 0) {
+        function inner(input) {
+            return !input;
+        }
+        return inner;
+    } else if (arguments.length != 1) {
+        var args = arguments;
+        function inner(input){
+            let all_arguments = Array.from(args);
+            all_arguments_length = all_arguments.length;
+            index = all_arguments.indexOf(input);
+            return all_arguments[(index + 1) % all_arguments_length];
+        }
+        return inner
+    } else if (arguments[0] instanceof Array){
+        args = arguments[0];
+        function inner(input){
+            let all_arguments = args;
+            all_arguments_length = all_arguments.length;
+            index = all_arguments.indexOf(input);
+            return all_arguments[(index + 1) % all_arguments_length];
+        }
+        return inner   
+    } else {
+        obj = arguments[0];
+        function inner(input) {
+            inner_obj = obj;
+            return inner_obj[input];
+        }
+        return inner
+    }
+}

test/utility.js

@@ -465,4 +465,25 @@
     assert.strictEqual(template(), '<<\nx\n>>');
   });
 
+
+  QUnit.test('transition function - toggles the input in several values.', function(assert) {
+    // assert.expect(1);
+    // var template = _.template('<<\nx\n>>', null, {evaluate: /<<(.*?)>>/g});
+    // assert.strictEqual(template(), '<<\nx\n>>');
+    toggler = _.getTogglingfunction()
+    var input = true;
+    assert.strictEqual(toggler(input), false)
+    toggler = _.getTogglingfunction([1, 2, 3])
+    var input = 3;
+    assert.strictEqual(toggler(input), 1)
+    toggler = _.getTogglingfunction({
+      'red': 'green',
+      'yellow': 'red',
+      'green': 'yellow'
+    })
+    var input = 'green';
+    assert.strictEqual(toggler(input), 'yellow')   
+  });
+
 }());
+