Remove deprecated design routes

https://gitlab.com/gitlab-org/gitlab/-/issues/208256

ee/changelogs/unreleased/208256-remove-deprecated-design-management-routes.yml

+---
+title: Remove deprecated route for serving full-size Design Management design files
+merge_request: 30917
+author:
+type: removed

ee/config/routes/project.rb

@@ -43,20 +43,6 @@ constraints(::Constraints::ProjectUrlConstrainer.new) do
           end
         end
 
-        # DEPRECATED: Remove this redirection in GitLab 13.0.
-        # This redirection supports old (pre-12.9) routes to Design Management raw images.
-        # https://gitlab.com/gitlab-org/gitlab/issues/208256
-        get '/designs/:id(/*ref)',
-          as: :design,
-          contraints: { id: /\d+/, ref: Gitlab::PathRegex.git_reference_regex },
-          to: redirect { |params|
-            namespace_id, project_id, id, ref = params.values_at(:namespace_id, :project_id, :id, :ref)
-            # The :ref route segment is optional in both this route, and the route
-            # we redirect to (where it is called :sha).
-            ref_path = "/#{ref}" if ref
-            "#{namespace_id}/#{project_id}/-/design_management/designs/#{id}#{ref_path}/raw_image"
-          }
-
         namespace :design_management do
           namespace :designs, path: 'designs/:design_id(/:sha)', constraints: -> (params) { params[:sha].nil? || Gitlab::Git.commit_id?(params[:sha]) } do
             resource :raw_image, only: :show

ee/spec/features/projects/issues/design_management/user_views_design_images_spec.rb

@@ -16,7 +16,7 @@ describe 'Users views raw design image files' do
   end
 
   it 'serves the latest design version when no ref is given' do
-    visit project_design_path(design.project, design)
+    visit project_design_management_designs_raw_image_path(design.project, design)
 
     expect(response_headers[Gitlab::Workhorse::SEND_DATA_HEADER]).to eq(
       workhorse_data_header_for_version(oldest_version.sha)
@@ -24,7 +24,7 @@ describe 'Users views raw design image files' do
   end
 
   it 'serves the correct design version when a ref is given' do
-    visit project_design_path(design.project, design, oldest_version.sha)
+    visit project_design_management_designs_raw_image_path(design.project, design, oldest_version.sha)
 
     expect(response_headers[Gitlab::Workhorse::SEND_DATA_HEADER]).to eq(
       workhorse_data_header_for_version(oldest_version.sha)

ee/spec/routing/project_routing_spec.rb

@@ -57,15 +57,6 @@ describe 'EE-specific project routing' do
     end
   end
 
-  describe 'Deprecated Design management legacy paths' do
-    include RSpec::Rails::RequestExampleGroup
-
-    it 'redirects to canonical path' do
-      expect(get('/gitlab/gitlabhq/-/designs/1/c6f00aa50b80887ada30a6fe517670be9f8f9ece')).to redirect_to('/gitlab/gitlabhq/-/design_management/designs/1/c6f00aa50b80887ada30a6fe517670be9f8f9ece/raw_image')
-      expect(get('/gitlab/gitlabhq/-/designs/1')).to redirect_to('/gitlab/gitlabhq/-/design_management/designs/1/raw_image')
-    end
-  end
-
   describe Projects::AutocompleteSourcesController, 'routing' do
     it "to #epics" do
       expect(get("/gitlab/gitlabhq/-/autocomplete_sources/epics")).to route_to("projects/autocomplete_sources#epics", namespace_id: 'gitlab', project_id: 'gitlabhq')