ignore the column before the migration

reword the changelog
remove dead code in the specs

app/models/merge_request.rb

@@ -8,7 +8,8 @@ class MergeRequest < ActiveRecord::Base
   include CreatedAtFilterable
   include TimeTrackable
 
-  ignore_column :locked_at
+  ignore_column :locked_at,
+                :ref_fetched
 
   belongs_to :target_project, class_name: "Project"
   belongs_to :source_project, class_name: "Project"

changelogs/unreleased/remove-ensure-ref-fetched-from-controllers.yml

 ---
-title: Removed merge requests fetching their refs on every action.
+title: Stop merge requests from fetching their refs when the data is already available.
 merge_request: 15129
 author:
 type: removed

spec/factories/merge_requests.rb

@@ -83,10 +83,10 @@ FactoryGirl.define do
       target_project = merge_request.target_project
       source_project = merge_request.source_project
 
-      # Fake `write_ref` if we don't have repository
+      # Fake `fetch_ref!` if we don't have repository
       # We have too many existing tests replying on this behaviour
       unless [target_project, source_project].all?(&:repository_exists?)
-        allow(merge_request).to receive(:write_ref)
+        allow(merge_request).to receive(:fetch_ref!)
       end
     end
 

spec/requests/api/merge_requests_spec.rb

@@ -623,8 +623,6 @@ describe API::MergeRequests do
 
       before do
         forked_project.add_reporter(user2)
-
-        allow_any_instance_of(MergeRequest).to receive(:write_ref)
       end
 
       it "returns merge_request" do

spec/requests/api/v3/merge_requests_spec.rb

@@ -319,8 +319,6 @@ describe API::MergeRequests do
 
       before do
         forked_project.add_reporter(user2)
-
-        allow_any_instance_of(MergeRequest).to receive(:write_ref)
       end
 
       it "returns merge_request" do