Updating forEach to handle non iterable values

lib/forEach.js

 'use strict';
 
+
+function isArrayLike(obj) {
+  return obj.constructor === Array || typeof obj.callee === 'function';
+}
+
 /**
  * Iterate over an Array or an Object invoking a function for each item.
  *
@@ -13,12 +18,20 @@
  * @param {Function} fn The callback to invoke for each item
  */
 module.exports = function forEach(obj, fn) {
-  if (typeof obj !== 'object') {
+  // Don't bother if no value provided
+  if (obj === null || typeof obj === 'undefined') {
     return;
   }
 
+  var isArray = isArrayLike(obj);
+
+  // Force an array if not already something iterable
+  if (typeof obj !== 'object' && !isArray) {
+    obj = [obj];
+  }
+
   // Iterate over array values
-  if (obj.constructor === Array || typeof obj.callee === 'function') {
+  if (isArray) {
     for (var i=0, l=obj.length; i<l; i++) {
       fn.call(null, obj[i], i, obj);
     }

lib/transformData.js

@@ -11,10 +11,6 @@ var forEach = require('./forEach');
  * @returns {*} The resulting transformed data
  */
 module.exports = function transformData(data, headers, fns) {
-  if (typeof fns === 'function') {
-    return fns(data, headers);
-  }
-
   forEach(fns, function (fn) {
     data = fn(data, headers);
   });

test/unit/forEach.js

@@ -29,5 +29,27 @@ module.exports = {
     test.equal(keys, 'bar');
     test.equal(vals, 6);
     test.done();
+  },
+
+  testUndefined: function (test) {
+    var count = 0;
+
+    forEach(undefined, function () {
+      count++;
+    });
+
+    test.equals(count, 0);
+    test.done();
+  },
+
+  testFunction: function (test) {
+    var count = 0;
+
+    forEach(function () {}, function () {
+      count++;
+    })
+
+    test.equals(count, 1);
+    test.done();
   }
 };
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