Merge branch 'ph/280579/fixDiffMetadataStartupJS' into 'master'

Fixes diff metadata StartupJS URL not matching

See merge request gitlab-org/gitlab!47265

app/controllers/projects/merge_requests/diffs_controller.rb

@@ -69,7 +69,7 @@ class Projects::MergeRequests::DiffsController < Projects::MergeRequests::Applic
     }
 
     options = additional_attributes.merge(
-      diff_view: Feature.enabled?(:unified_diff_lines, @merge_request.project, default_enabled: true) ? "inline" : diff_view,
+      diff_view: unified_diff_lines_view_type(@merge_request.project),
       merge_ref_head_diff: render_merge_ref_head_diff?
     )
 

app/controllers/projects/merge_requests_controller.rb

@@ -481,7 +481,7 @@ class Projects::MergeRequestsController < Projects::MergeRequests::ApplicationCo
 
   def endpoint_metadata_url(project, merge_request)
     params = request.query_parameters
-    params[:view] = cookies[:diff_view] if params[:view].blank? && cookies[:diff_view].present?
+    params[:view] = unified_diff_lines_view_type(project)
 
     if Feature.enabled?(:default_merge_ref_for_diffs, project)
       params = params.merge(diff_head: true)

app/helpers/diff_helper.rb

@@ -203,6 +203,14 @@ module DiffHelper
     set_secure_cookie(:diff_view, params.delete(:view), type: CookiesHelper::COOKIE_TYPE_PERMANENT) if params[:view].present?
   end
 
+  def unified_diff_lines_view_type(project)
+    if Feature.enabled?(:unified_diff_lines, project, default_enabled: true)
+      'inline'
+    else
+      diff_view
+    end
+  end
+
   private
 
   def diff_btn(title, name, selected)

changelogs/unreleased/ph-280579-fixDiffMetadataStartupJS.yml

+---
+title: Fixed diff metadata endpoint being called twice
+merge_request: 47265
+author:
+type: fixed

spec/controllers/projects/merge_requests_controller_spec.rb

@@ -95,7 +95,8 @@ RSpec.describe Projects::MergeRequestsController do
               project,
               merge_request,
               'json',
-              diff_head: true))
+              diff_head: true,
+              view: 'inline'))
         end
       end
 

spec/helpers/diff_helper_spec.rb

@@ -358,4 +358,30 @@ RSpec.describe DiffHelper do
       expect(diff_file_path_text(diff_file, max: 10)).to eq("...open.rb")
     end
   end
+
+  describe 'unified_diff_lines_view_type' do
+    before do
+      controller.params[:view] = 'parallel'
+    end
+
+    describe 'unified diffs enabled' do
+      before do
+        stub_feature_flags(unified_diff_lines: true)
+      end
+
+      it 'returns inline view' do
+        expect(helper.unified_diff_lines_view_type(project)).to eq 'inline'
+      end
+    end
+
+    describe 'unified diffs disabled' do
+      before do
+        stub_feature_flags(unified_diff_lines: false)
+      end
+
+      it 'returns parallel view' do
+        expect(helper.unified_diff_lines_view_type(project)).to eq :parallel
+      end
+    end
+  end
 end