Backport 'Rebase' feature from EE to CEjprovazn-rebase

When a project uses fast-forward merging strategy user has
to rebase MRs to target branch before it can be merged.
Now user can do rebase in UI by clicking 'Rebase' button
instead of doing rebase locally.

This feature was already present in EE, this is only backport
of the feature to CE. Couple of changes:
* removed rebase license check
* renamed migration (changed timestamp)

Closes #40301

2 files changed, 39 insertions, 0 deletions

diff --git a/features/project/ff_merge_requests.feature b/features/project/ff_merge_requests.feature
index 995e52f9332..39035d551d1 100644
--- a/features/project/ff_merge_requests.feature
+++ b/features/project/ff_merge_requests.feature
@@ -22,3 +22,20 @@ Feature: Project Ff Merge Requests
     Then I should see ff-only merge button
     When I accept this merge request
     Then I should see merged request
+
+  @javascript
+  Scenario: I do rebase before ff-only merge
+    Given ff merge enabled
+    And rebase before merge enabled
+    When I visit merge request page "Bug NS-05"
+    Then I should see rebase button
+    When I press rebase button
+    Then I should see rebase in progress message
+
+  @javascript
+  Scenario: I do rebase before regular merge
+    Given rebase before merge enabled
+    When I visit merge request page "Bug NS-05"
+    Then I should see rebase button
+    When I press rebase button
+    Then I should see rebase in progress message
diff --git a/features/steps/project/ff_merge_requests.rb b/features/steps/project/ff_merge_requests.rb
index d68fe71e16e..27efcfd65b6 100644
--- a/features/steps/project/ff_merge_requests.rb
+++ b/features/steps/project/ff_merge_requests.rb
@@ -17,6 +17,10 @@ class Spinach::Features::ProjectFfMergeRequests < Spinach::FeatureSteps
            author: project.users.first)
   end
 
+  step 'merge request is mergeable' do
+    expect(page).to have_button 'Merge'
+  end
+
   step 'I should see ff-only merge button' do
     expect(page).to have_content "Fast-forward merge without a merge commit"
     expect(page).to have_button 'Merge'
@@ -45,6 +49,10 @@ class Spinach::Features::ProjectFfMergeRequests < Spinach::FeatureSteps
     project.save!
   end
 
+  step 'I should see rebase button' do
+    expect(page).to have_button "Rebase"
+  end
+
   step 'merge request "Bug NS-05" is rebased' do
     merge_request.source_branch = 'flatten-dir'
     merge_request.target_branch = 'improve/awesome'
@@ -59,6 +67,20 @@ class Spinach::Features::ProjectFfMergeRequests < Spinach::FeatureSteps
     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 press rebase button' do
+    click_button "Rebase"
+  end
+
+  step "I should see rebase in progress message" do
+    expect(page).to have_content("Rebase in progress")
+  end
+
   def merge_request
     @merge_request ||= MergeRequest.find_by!(title: "Bug NS-05")
   end