Add post replacement create action test.

test/functional/post_replacements_controller_test.rb

@@ -3,7 +3,7 @@ require 'test_helper'
 class PostReplacementsControllerTest < ActionController::TestCase
   context "The post replacements controller" do
     setup do
-      @user = FactoryGirl.create(:user, can_approve_posts: true)
+      @user = FactoryGirl.create(:user, can_approve_posts: true, created_at: 1.month.ago)
       CurrentUser.user = @user
       CurrentUser.ip_addr = "127.0.0.1"
 
@@ -11,6 +11,28 @@ class PostReplacementsControllerTest < ActionController::TestCase
       @post_replacement = FactoryGirl.create(:post_replacement, post_id: @post.id)
     end
 
+    context "create action" do
+      should "render" do
+        params = {
+          format: :json,
+          post_id: @post.id,
+          post_replacement: {
+            replacement_url: "https://www.google.com/intl/en_ALL/images/logo.gif",
+          }
+        }
+
+        assert_difference("@post.replacements.size") do
+          post :create, params, { user_id: @user.id }
+          @post.reload
+        end
+
+        assert_response :success
+        assert_equal("https://www.google.com/intl/en_ALL/images/logo.gif", @post.source)
+        assert_equal("e80d1c59a673f560785784fb1ac10959", @post.md5)
+        assert_equal("e80d1c59a673f560785784fb1ac10959", Digest::MD5.file(@post.file_path).hexdigest)
+      end
+    end
+
     context "index action" do
       should "render" do
         get :index, {format: :json}