Consistent nextTick implementation

2 files changed, 35 insertions, 14 deletions

diff --git a/lib/internal/setImmediate.js b/lib/internal/setImmediate.js
index 7d15249..eb4ea63 100644
--- a/lib/internal/setImmediate.js
+++ b/lib/internal/setImmediate.js
@@ -1,21 +1,30 @@
 'use strict';
+
 import rest from 'lodash/rest';
 
-var _setImmediate = typeof setImmediate === 'function' && setImmediate;
+export var hasSetImmediate = typeof setImmediate === 'function' && setImmediate;
+export var hasNextTick = typeof process === 'object' && typeof process.nextTick === 'function';
+
+export function fallback(fn) {
+    setTimeout(fn, 0);
+}
+
+export function wrap(defer) {
+    return rest(function (fn, args) {
+         defer(function () {
+             fn.apply(null, args);
+         });
+     });
+}
 
 var _defer;
-if (_setImmediate) {
-    _defer = _setImmediate;
-} else if (typeof process === 'object' && typeof process.nextTick === 'function') {
+
+if (hasSetImmediate) {
+    _defer = setImmediate;
+} else if (hasNextTick) {
     _defer = process.nextTick;
 } else {
-    _defer = function(fn) {
-        setTimeout(fn, 0);
-    };
+    _defer = fallback;
 }
 
-export default rest(function (fn, args) {
-    _defer(function () {
-        fn.apply(null, args);
-    });
-});
+export default wrap(_defer);
diff --git a/lib/nextTick.js b/lib/nextTick.js
index 66a4c1f..a69b87e 100644
--- a/lib/nextTick.js
+++ b/lib/nextTick.js
@@ -1,4 +1,6 @@
-import setImmediate from './internal/setImmediate';
+'use strict';
+
+import { hasNexTick, hasSetImmediate, fallback, wrap }  from './internal/setImmediate';
 
 /**
  * Calls `callback` on a later loop around the event loop. In Node.js this just
@@ -30,4 +32,14 @@ import setImmediate from './internal/setImmediate';
  *     // a, b, and c equal 1, 2, and 3
  * }, 1, 2, 3);
  */
-export default setImmediate;
+var _defer;
+
+if (hasNexTick) {
+    _defer = process.nextTick;
+} else if (hasSetImmediate) {
+    _defer = setImmediate;
+} else {
+    _defer = fallback;
+}
+
+export default wrap(_defer);