Merge branch '43263-git-push-option-to-create-mr' into 'master'

Git push options to create a merge request, set target_branch and set merge when pipeline succeeds

Closes #53198 and #43263

See merge request gitlab-org/gitlab-ce!26752

3 files changed, 164 insertions, 2 deletions

diff --git a/app/services/ci/create_pipeline_service.rb b/app/services/ci/create_pipeline_service.rb
index 8973c5ffc9e..41dee4e5641 100644
--- a/app/services/ci/create_pipeline_service.rb
+++ b/app/services/ci/create_pipeline_service.rb
@@ -37,7 +37,7 @@ module Ci
         variables_attributes: params[:variables_attributes],
         project: project,
         current_user: current_user,
-        push_options: params[:push_options],
+        push_options: params[:push_options] || {},
         chat_data: params[:chat_data],
         **extra_options(options))
 
diff --git a/app/services/merge_requests/push_options_handler_service.rb b/app/services/merge_requests/push_options_handler_service.rb
new file mode 100644
index 00000000000..d92eb0a68c3
--- /dev/null
+++ b/app/services/merge_requests/push_options_handler_service.rb
@@ -0,0 +1,162 @@
+# frozen_string_literal: true
+
+module MergeRequests
+  class PushOptionsHandlerService
+    LIMIT = 10
+
+    attr_reader :branches, :changes_by_branch, :current_user, :errors,
+                :project, :push_options, :target_project
+
+    def initialize(project, current_user, changes, push_options)
+      @project = project
+      @target_project = @project.default_merge_request_target
+      @current_user = current_user
+      @branches = get_branches(changes)
+      @push_options = push_options
+      @errors = []
+    end
+
+    def execute
+      validate_service
+      return self if errors.present?
+
+      branches.each do |branch|
+        execute_for_branch(branch)
+      rescue Gitlab::Access::AccessDeniedError
+        errors << 'User access was denied'
+      rescue StandardError => e
+        Gitlab::AppLogger.error(e)
+        errors << 'An unknown error occurred'
+      end
+
+      self
+    end
+
+    private
+
+    def get_branches(raw_changes)
+      Gitlab::ChangesList.new(raw_changes).map do |changes|
+        next unless Gitlab::Git.branch_ref?(changes[:ref])
+
+        # Deleted branch
+        next if Gitlab::Git.blank_ref?(changes[:newrev])
+
+        # Default branch
+        branch_name = Gitlab::Git.branch_name(changes[:ref])
+        next if branch_name == target_project.default_branch
+
+        branch_name
+      end.compact.uniq
+    end
+
+    def validate_service
+      errors << 'User is required' if current_user.nil?
+
+      unless target_project.merge_requests_enabled?
+        errors << "Merge requests are not enabled for project #{target_project.full_path}"
+      end
+
+      if branches.size > LIMIT
+        errors << "Too many branches pushed (#{branches.size} were pushed, limit is #{LIMIT})"
+      end
+
+      if push_options[:target] && !target_project.repository.branch_exists?(push_options[:target])
+        errors << "Branch #{push_options[:target]} does not exist"
+      end
+    end
+
+    # Returns a Hash of branch => MergeRequest
+    def merge_requests
+      @merge_requests ||= MergeRequest.from_project(target_project)
+                                      .opened
+                                      .from_source_branches(branches)
+                                      .index_by(&:source_branch)
+    end
+
+    def execute_for_branch(branch)
+      merge_request = merge_requests[branch]
+
+      if merge_request
+        update!(merge_request)
+      else
+        create!(branch)
+      end
+    end
+
+    def create!(branch)
+      unless push_options[:create]
+        errors << "A merge_request.create push option is required to create a merge request for branch #{branch}"
+        return
+      end
+
+      # Use BuildService to assign the standard attributes of a merge request
+      merge_request = ::MergeRequests::BuildService.new(
+        project,
+        current_user,
+        create_params(branch)
+      ).execute
+
+      unless merge_request.errors.present?
+        merge_request = ::MergeRequests::CreateService.new(
+          project,
+          current_user,
+          merge_request.attributes
+        ).execute
+      end
+
+      collect_errors_from_merge_request(merge_request) unless merge_request.persisted?
+    end
+
+    def update!(merge_request)
+      merge_request = ::MergeRequests::UpdateService.new(
+        target_project,
+        current_user,
+        update_params
+      ).execute(merge_request)
+
+      collect_errors_from_merge_request(merge_request) unless merge_request.valid?
+    end
+
+    def create_params(branch)
+      params = {
+        assignee: current_user,
+        source_branch: branch,
+        source_project: project,
+        target_branch: push_options[:target] || target_project.default_branch,
+        target_project: target_project
+      }
+
+      if push_options.key?(:merge_when_pipeline_succeeds)
+        params.merge!(
+          merge_when_pipeline_succeeds: push_options[:merge_when_pipeline_succeeds],
+          merge_user: current_user
+        )
+      end
+
+      params
+    end
+
+    def update_params
+      params = {}
+
+      if push_options.key?(:merge_when_pipeline_succeeds)
+        params.merge!(
+          merge_when_pipeline_succeeds: push_options[:merge_when_pipeline_succeeds],
+          merge_user: current_user
+        )
+      end
+
+      if push_options.key?(:target)
+        params[:target_branch] = push_options[:target]
+      end
+
+      params
+    end
+
+    def collect_errors_from_merge_request(merge_request)
+      merge_request.errors.full_messages.each do |error|
+        errors << error
+      end
+    end
+  end
+end
diff --git a/app/workers/post_receive.rb b/app/workers/post_receive.rb
index 396f44396a3..a5554f07699 100644
--- a/app/workers/post_receive.rb
+++ b/app/workers/post_receive.rb
@@ -3,7 +3,7 @@
 class PostReceive
   include ApplicationWorker
 
-  def perform(gl_repository, identifier, changes, push_options = [])
+  def perform(gl_repository, identifier, changes, push_options = {})
     project, repo_type = Gitlab::GlRepository.parse(gl_repository)
 
     if project.nil?