Add some tests for merge API

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

CHANGELOG

@@ -14,6 +14,7 @@ v 6.9.0
   - Fix wiki backup skip bug
   - Two Step MR creation process
   - Remove unwanted files from satellite working directory with git clean -fdx
+  - Accept merge request via API (sponsored by O'Reilly Media)
 
 v 6.8.0
   - Ability to at mention users that are participating in issue and merge req. discussion

lib/api/merge_requests.rb

@@ -129,7 +129,7 @@ module API
                    :push_code
                  end
 
-        if can?(current_user, action, project)
+        if can?(current_user, action, user_project)
           if merge_request.unchecked?
             merge_request.check_if_can_be_merged
           end

spec/requests/api/merge_requests_spec.rb

@@ -183,11 +183,18 @@ describe API::API, api: true  do
     end
   end
 
-  describe "PUT /projects/:id/merge_request/:merge_request_id to merge MR" do
-    it "should return merge_request" do
-      put api("/projects/#{project.id}/merge_request/#{merge_request.id}", user), state_event: "merge"
+  describe "PUT /projects/:id/merge_request/:merge_request_id/merge" do
+    it "should return merge_request in case of success" do
+      MergeRequest.any_instance.stub(can_be_merged?: true, automerge!: true)
+      put api("/projects/#{project.id}/merge_request/#{merge_request.id}/merge", user)
       response.status.should == 200
-      json_response['state'].should == 'merged'
+    end
+
+    it "should return 405 if branch can't be merged" do
+      MergeRequest.any_instance.stub(can_be_merged?: false)
+      put api("/projects/#{project.id}/merge_request/#{merge_request.id}/merge", user)
+      response.status.should == 405
+      json_response['message'].should == 'Branch cannot be merged'
     end
   end