pathTraverse method support simplify generator rather than standard t…

…wo-element array.

README.md

@@ -158,6 +158,7 @@ For example, set postfix `v0.2.5`, will generate tags below:
 Type: Array
 
 Value consists of two-element array, the first is `generator`, the second is `config`.  Generally speaking, any `gulp-plugin` exports `generator` here, and `config` property pass to the `generator`. Declare how to resolve css type block files. if omitted or null, will only concat related files.
+Also, you can just use `generator` here rather than two-element array when no additional options should pass in the `generator`.
 
 For example:
 ```javascript

test/utils.file.spec.js

@@ -27,13 +27,21 @@ describe('utils path traverse method', function () {
     });
   });
 
-  it('should achieve path traverse', function () {
+  it('should support path traverse when provide standard two-element array', function () {
     let stream = utils.pathTraverse(['test/fixture/script/origin.js'], [[generatePassStream, {}]]);
     let promise = utils.streamToPromise(stream);
     return promise.then(function(value) {
       value.toString().should.equal("PASS angular.module('cloud', []);");
     });
   });
+
+  it('should support path traverse when provide simplify generator element array', function () {
+    let stream = utils.pathTraverse(['test/fixture/script/origin.js'], [generatePassStream]);
+    let promise = utils.streamToPromise(stream);
+    return promise.then(function(value) {
+      value.toString().should.equal("PASS angular.module('cloud', []);");
+    });
+  });
 });
 
 describe('utils resolveFileSource method', function () {

utils/utils.js

@@ -328,8 +328,15 @@ utils.pathTraverse = function(originPath, flow, debug) {
   var stream = vfs.src(destinyPath);
   if (util.isArray(flow)) {
     for (var i = 0; i < flow.length; i++) {
-      var generator = flow[i][0];
-      var options = flow[i][1];
+      let generator, options;
+      if (util.isArray(flow[i])) {
+        generator = flow[i][0];
+        options = flow[i][1];
+      }
+      if (util.isFunction(flow[i])) {
+        generator = flow[i];
+        options = {};
+      }
       stream = stream.pipe(generator(options));
     }
   }