Add some tests for ff-only feature

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

features/project/ff_merge_requests.feature

+Feature: Project Ff Merge Requests
+  Background:
+    Given I sign in as a user
+    And I own project "Shop"
+    And project "Shop" have "Bug NS-05" open merge request with diffs inside
+    And ff merge enabled
+    And merge request "Bug NS-05" is mergeable
+
+  Scenario: I do ff-only merge
+    Given merge request "Bug NS-05" is rebased
+    When I visit merge request page "Bug NS-05"
+    Then I should see ff-only merge button
+
+  Scenario: I do rebase before ff-only merge
+    Given rebase before merge enabled
+    When I visit merge request page "Bug NS-05"
+    Then I should see rebase button
+
+  Scenario: I should do rebase before ff-only merge
+    When I visit merge request page "Bug NS-05"
+    Then I should not see rebase button
+    And I should see rebase message

features/project/merge_requests.feature

@@ -269,12 +269,3 @@ Feature: Project Merge Requests
     And I select "fix" as source
     Then I see auto-suggested approver
     And I can add it to approver list
-
-
-  Scenario: I should see rebase checkbox
-    Given project "Shop" have "Bug NS-05" open merge request with diffs inside
-    And rebase before merge enabled
-    And merge request "Bug NS-05" is mergeable
-    And I visit merge request page "Bug NS-05"
-    And merge request is mergeable
-    Then I should see rebase checkbox

features/steps/project/ff_merge_requests.rb

+class Spinach::Features::ProjectFfMergeRequests < Spinach::FeatureSteps
+  include SharedAuthentication
+  include SharedIssuable
+  include SharedProject
+  include SharedNote
+  include SharedPaths
+  include SharedMarkdown
+  include SharedDiffNote
+  include SharedUser
+
+  step 'project "Shop" have "Bug NS-05" open merge request with diffs inside' do
+    create(:merge_request_with_diffs,
+           title: "Bug NS-05",
+           source_project: project,
+           target_project: project,
+           author: project.users.first)
+  end
+
+  step 'merge request is mergeable' do
+    expect(page).to have_button 'Accept Merge Request'
+  end
+
+  step 'I should see ff-only merge button' do
+    expect(page).to have_content "Fast-forward merge without creating merge commit"
+    expect(page).to have_button 'Accept Merge Request'
+  end
+
+  step 'merge request "Bug NS-05" is mergeable' do
+    merge_request.mark_as_mergeable
+  end
+
+  step 'I accept this merge request' do
+    page.within '.mr-state-widget' do
+      click_button "Accept Merge Request"
+    end
+  end
+
+  step 'I should see merged request' do
+    page.within '.issue-box' do
+      expect(page).to have_content "Merged"
+    end
+  end
+
+  step 'ff merge enabled' do
+    project = merge_request.target_project
+    project.merge_requests_ff_only_enabled = true
+    project.save!
+  end
+
+  step 'I should not see rebase button' do
+    expect(page).to_not have_button "Rebase"
+  end
+
+  step 'I should see rebase button' do
+    expect(page).to have_button "Rebase"
+  end
+
+  step 'I should see rebase message' do
+    expect(page).to have_content "Fast-forward merge is not possible. Branch must be rebased first"
+  end
+
+  step 'merge request "Bug NS-05" is rebased' do
+    merge_request.source_branch = 'flatten-dir'
+    merge_request.target_branch = 'improve/awesome'
+    merge_request.reload_code
+    merge_request.save!
+  end
+
+  step 'rebase before merge enabled' do
+    project = merge_request.target_project
+    project.merge_requests_rebase_enabled = true
+    project.save!
+  end
+
+  step 'I click on "Email Patches"' do
+    click_link "Email Patches"
+  end
+
+  step 'I click on "Plain Diff"' do
+    click_link "Plain Diff"
+  end
+
+  step 'I should see a patch diff' do
+    expect(page).to have_content('diff --git')
+  end
+
+  def merge_request
+    @merge_request ||= MergeRequest.find_by!(title: "Bug NS-05")
+  end
+end

features/steps/project/merge_requests.rb

@@ -432,16 +432,6 @@ class Spinach::Features::ProjectMergeRequests < Spinach::FeatureSteps
     end
   end
 
-  step 'rebase before merge enabled' do
-    project = merge_request.target_project
-    project.merge_requests_rebase_enabled = true
-    project.save!
-  end
-
-  step 'I should see rebase checkbox' do
-    expect(page).to have_content 'Rebase before merge'
-  end
-
   step 'I click on "Email Patches"' do
     click_link "Email Patches"
   end