Merge when build succeeds

3 files changed, 64 insertions, 1 deletions

diff --git a/app/services/merge_requests/merge_when_build_succeeds_service.rb b/app/services/merge_requests/merge_when_build_succeeds_service.rb
new file mode 100644
index 00000000000..a4418360b8c
--- /dev/null
+++ b/app/services/merge_requests/merge_when_build_succeeds_service.rb
@@ -0,0 +1,43 @@
+module MergeRequests
+  class MergeWhenBuildSucceedsService < MergeRequests::BaseService
+    def execute(merge_request)
+      merge_request.merge_params.merge!(params[:merge_params])
+
+      # The service is also called when the merge params are updated.
+      already_approved = merge_request.merge_when_build_succeeds?
+
+      unless already_approved
+        merge_request.merge_when_build_succeeds = true
+        merge_request.merge_user                = @current_user
+      end
+
+      merge_request.save
+
+      unless already_approved
+        SystemNoteService.merge_when_build_succeeds(merge_request, @project, @current_user)
+      end
+    end
+
+    def trigger(build)
+      merge_requests = merge_request_from(build)
+
+      merge_requests.each do |merge_request|
+        next unless merge_request.merge_when_build_succeeds?
+
+        ci_commit = merge_request.ci_commit
+        if ci_commit && ci_commit.success? && merge_request.mergeable?
+          MergeWorker.perform_async(merge_request.id, merge_request.merge_user_id, merge_request.merge_params)
+        end
+      end
+    end
+
+    private
+
+    def merge_request_from(build)
+      merge_requests = @project.origin_merge_requests.opened.where(source_branch: build.ref).to_a
+      merge_requests += @project.fork_merge_requests.opened.where(source_branch: build.ref).to_a
+
+      merge_requests.uniq.select(&:source_project)
+    end
+  end
+end
diff --git a/app/services/merge_requests/refresh_service.rb b/app/services/merge_requests/refresh_service.rb
index d68bc79ecc0..335ef32abce 100644
--- a/app/services/merge_requests/refresh_service.rb
+++ b/app/services/merge_requests/refresh_service.rb
@@ -8,6 +8,7 @@ module MergeRequests
 
       find_new_commits
       reload_merge_requests
+      reset_merge_when_build_succeeds
 
       # Leave a system note if a branch was deleted/added
       if branch_added? || branch_removed?
@@ -57,7 +58,6 @@ module MergeRequests
       merge_requests = filter_merge_requests(merge_requests)
 
       merge_requests.each do |merge_request|
-
         if merge_request.source_branch == @branch_name || force_push?
           merge_request.reload_code
           merge_request.mark_as_unchecked
@@ -76,6 +76,12 @@ module MergeRequests
       end
     end
 
+    def reset_merge_when_build_succeeds
+      merge_requests_for_source_branch.each do |merge_request|
+        merge_request.reset_merge_when_build_succeeds
+      end
+    end
+
     def find_new_commits
       if branch_added?
         @commits = []
diff --git a/app/services/system_note_service.rb b/app/services/system_note_service.rb
index 708c2f00486..c9846e9f26f 100644
--- a/app/services/system_note_service.rb
+++ b/app/services/system_note_service.rb
@@ -130,6 +130,20 @@ class SystemNoteService
     create_note(noteable: noteable, project: project, author: author, note: body)
   end
 
+  # Called when 'merge when build succeeds' is executed
+  def self.merge_when_build_succeeds(noteable, project, author)
+    body = "Approved this request to be merged automatically when the build succeeds"
+
+    create_note(noteable: noteable, project: project, author: author, note: body)
+  end
+
+  # Called when 'merge when build succeeds' is canceled
+  def self.cancel_merge_when_build_succeeds(noteable, project, author)
+    body = "Canceled the automatic merge"
+
+    create_note(noteable: noteable, project: project, author: author, note: body)
+  end
+
   # Called when the title of a Noteable is changed
   #
   # noteable  - Noteable object that responds to `title`