Merge branch 'blackst0ne-squash-and-merge-in-gitlab-core-ce' into 'master'

Resolve "Squash and merge in GitLab Core (CE)"

Closes #34591

See merge request gitlab-org/gitlab-ce!18956

4 files changed, 13 insertions, 10 deletions

diff --git a/lib/api/entities.rb b/lib/api/entities.rb
index 3688b44b8df..49cd4fccc63 100644
--- a/lib/api/entities.rb
+++ b/lib/api/entities.rb
@@ -568,6 +568,8 @@ module API
       expose :time_stats, using: 'API::Entities::IssuableTimeStats' do |merge_request|
         merge_request
       end
+
+      expose :squash
     end
 
     class MergeRequest < MergeRequestBasic
diff --git a/lib/api/merge_requests.rb b/lib/api/merge_requests.rb
index bc4df16e3a8..1ba9a09346f 100644
--- a/lib/api/merge_requests.rb
+++ b/lib/api/merge_requests.rb
@@ -10,12 +10,6 @@ module API
     helpers do
       params :optional_params_ee do
       end
-
-      params :merge_params_ee do
-      end
-
-      def update_merge_request_ee(merge_request)
-      end
     end
 
     def self.update_params_at_least_one_of
@@ -29,6 +23,7 @@ module API
         target_branch
         title
         discussion_locked
+        squash
       ]
     end
 
@@ -146,6 +141,7 @@ module API
           optional :labels, type: String, desc: 'Comma-separated list of label names'
           optional :remove_source_branch, type: Boolean, desc: 'Remove source branch when merging'
           optional :allow_maintainer_to_push, type: Boolean, desc: 'Whether a maintainer of the target project can push to the source project'
+          optional :squash, type: Grape::API::Boolean, desc: 'When true, the commits will be squashed into a single commit on merge'
 
           use :optional_params_ee
         end
@@ -308,8 +304,7 @@ module API
         optional :merge_when_pipeline_succeeds, type: Boolean,
                                                 desc: 'When true, this merge request will be merged when the pipeline succeeds'
         optional :sha, type: String, desc: 'When present, must have the HEAD SHA of the source branch'
-
-        use :merge_params_ee
+        optional :squash, type: Grape::API::Boolean, desc: 'When true, the commits will be squashed into a single commit on merge'
       end
       put ':id/merge_requests/:merge_request_iid/merge' do
         Gitlab::QueryLimiting.whitelist('https://gitlab.com/gitlab-org/gitlab-ce/issues/42317')
@@ -327,7 +322,7 @@ module API
 
         check_sha_param!(params, merge_request)
 
-        update_merge_request_ee(merge_request)
+        merge_request.update(squash: params[:squash]) if params[:squash]
 
         merge_params = {
           commit_message: params[:merge_commit_message],
diff --git a/lib/api/v3/entities.rb b/lib/api/v3/entities.rb
index 68b4d7c3982..28fcf6c6e84 100644
--- a/lib/api/v3/entities.rb
+++ b/lib/api/v3/entities.rb
@@ -134,6 +134,8 @@ module API
         expose :should_remove_source_branch?, as: :should_remove_source_branch
         expose :force_remove_source_branch?, as: :force_remove_source_branch
 
+        expose :squash
+
         expose :web_url do |merge_request, options|
           Gitlab::UrlBuilder.build(merge_request)
         end
diff --git a/lib/api/v3/merge_requests.rb b/lib/api/v3/merge_requests.rb
index 9b0f70e2bfe..af5afd1c334 100644
--- a/lib/api/v3/merge_requests.rb
+++ b/lib/api/v3/merge_requests.rb
@@ -44,6 +44,7 @@ module API
             optional :milestone_id, type: Integer, desc: 'The ID of a milestone to assign the merge request'
             optional :labels, type: String, desc: 'Comma-separated list of label names'
             optional :remove_source_branch, type: Boolean, desc: 'Remove source branch when merging'
+            optional :squash, type: Boolean, desc: 'Squash commits when merging'
           end
         end
 
@@ -166,7 +167,7 @@ module API
             use :optional_params
             at_least_one_of :title, :target_branch, :description, :assignee_id,
                             :milestone_id, :labels, :state_event,
-                            :remove_source_branch
+                            :remove_source_branch, :squash
           end
           put path do
             Gitlab::QueryLimiting.whitelist('https://gitlab.com/gitlab-org/gitlab-ce/issues/42127')
@@ -195,6 +196,7 @@ module API
             optional :merge_when_build_succeeds, type: Boolean,
                                                  desc: 'When true, this merge request will be merged when the build succeeds'
             optional :sha, type: String, desc: 'When present, must have the HEAD SHA of the source branch'
+            optional :squash, type: Boolean, desc: 'When true, the commits will be squashed into a single commit on merge'
           end
           put "#{path}/merge" do
             merge_request = find_project_merge_request(params[:merge_request_id])
@@ -211,6 +213,8 @@ module API
               render_api_error!("SHA does not match HEAD of source branch: #{merge_request.diff_head_sha}", 409)
             end
 
+            merge_request.update(squash: params[:squash]) if params[:squash]
+
             merge_params = {
               commit_message: params[:merge_commit_message],
               should_remove_source_branch: params[:should_remove_source_branch]