check if the path have a pre handler. Qiu

demo/blog/build_prod.config.js

@@ -2,7 +2,7 @@
 
 module.exports = {
     seleniumHost: 'http://localhost:4444/wd/hub',
-    browsers: ['firefox', 'chrome'],
+    browsers: ['firefox', 'safari'],
     envHosts: {
       build: 'http://localhost:4000',
       prod: 'http://www.ishouldbeageek.me'

demo/blog/links.js

@@ -4,7 +4,9 @@ module.exports = (function initLinks() {
 
   return [
     '/404.html',
-    '/'
+    ['/', function (driver, webdriver) {
+      // driver.findElement(webdriver.By.partialLinkText('Subscribe')).click();
+    }]
   ];
 
 })();

src/viff.coffee

@@ -19,8 +19,10 @@ class Viff
       @drivers[browserName] = driver
 
     envName = _.first(envName for envName of envHost)
-    driver.get envHost[envName] + url
+    [url, preHandle] = url if _.isArray url
 
+    driver.get envHost[envName] + url
+    preHandle driver, webdriver if _.isFunction preHandle
     driver.takeScreenshot().then (base64Img) -> 
       defer.resolve base64Img
 
@@ -39,6 +41,7 @@ class Viff
       compares[browser] = compares[browser] || {}
       
       _.each links, (url) ->
+        url = _.first url if _.isFunction url[1]
         envCompares = {}
 
         _.each envHosts, (host, env) ->

test/src/viff_test.coffee

@@ -1,6 +1,7 @@
 Viff = require '../../lib/viff.js'
 sinon = require 'sinon'
 _ = require 'underscore'
+webdriver = require 'selenium-webdriver'
 
 module.exports = 
   setUp: (callback) ->
@@ -65,6 +66,25 @@ module.exports =
     test.ok callback.calledWith 'base64string'
     test.done()
 
+  'it should invoke pre handler before take screenshot': (test) ->
+    envHost = 
+      build: 'http://localhost:4000'
+
+    preHandler = sinon.spy()
+
+    link = ['/path', preHandler]
+    @viff.takeScreenshot('firefox', envHost, link)
+
+    test.ok preHandler.calledWith @driver, webdriver
+    test.done()
+
+  'it should use correct path when set pre handler': (test) ->
+    links = [['/404.html', (driver, webdriver) -> ]]
+    callback = (compares) -> 
+      test.equals _.first(_.keys(compares.firefox)), '/404.html'
+      test.done()
+    @viff.takeScreenshots @config.browsers, @config.compare, links, callback
+
   'it should take many screenshots according to config': (test) ->
     format = 
       safari: