Remove design reference filter

This removes the existing (unreleased) design reference filter.

It will be replaced with a new one when we complete the re-architecture
of designs to nest under project with an `iid` field. For this reason,
the design reference parser has been retained.

ee/lib/banzai/filter/design_reference_filter.rb

-# frozen_string_literal: true
-
-module Banzai
-  module Filter
-    class DesignReferenceFilter < AbstractReferenceFilter
-      include Gitlab::Allowable
-
-      Identifier = Struct.new(:issue_iid, :filename, keyword_init: true)
-
-      self.reference_type = :design
-
-      # This filter must be enabled by setting the following flags:
-      #  - design_management
-      #  - design_management_reference_filter_gfm_pipeline
-      def call
-        return doc unless enabled?
-
-        super
-      end
-
-      def find_object(project, identifier)
-        records_per_parent[project][identifier]
-      end
-
-      def parent_records(project, identifiers)
-        return [] unless can_read_designs?(project)
-
-        iids      = identifiers.map(&:issue_iid).to_set
-        filenames = identifiers.map(&:filename).to_set
-        issues    = project.issues.where(iid: iids)
-        issue_map = issues.index_by(&:id)
-
-        designs(issues.to_a, filenames).select do |d|
-          issue = issue_map[d.issue_id]
-          # assign values we have already fetched
-          d.project = project
-          d.issue = issue
-          identifiers.include?(Identifier.new(filename: d.filename, issue_iid: issue.iid))
-        end
-      end
-
-      def relation_for_paths(paths)
-        super.includes(:route, :namespace, :group)
-      end
-
-      def parent_type
-        :project
-      end
-
-      # optimisation to reuse the parent_per_reference query information
-      def parent_from_ref(ref)
-        parent_per_reference[ref || current_parent_path]
-      end
-
-      def url_for_object(design, project)
-        path_options = { vueroute: design.filename }
-        Gitlab::Routing.url_helpers.designs_project_issue_path(project, design.issue, path_options)
-      end
-
-      def data_attributes_for(_text, _project, design, **_kwargs)
-        super.merge(issue: design.issue_id)
-      end
-
-      def self.object_class
-        ::DesignManagement::Design
-      end
-
-      def self.object_sym
-        :design
-      end
-
-      def self.parse_symbol(raw, match_data)
-        filename = parse_filename(raw, match_data)
-        iid = match_data[:issue].to_i
-        Identifier.new(filename: filename, issue_iid: iid)
-      end
-
-      def self.parse_filename(raw, match_data)
-        if name = match_data[:simple_file_name]
-          name
-        elsif efn = match_data[:escaped_filename]
-          efn.gsub(/(\\ \\ | \\ ")/x) { |x| x[1] }
-        elsif b64_name = match_data[:base_64_encoded_name]
-          Base64.decode64(b64_name)
-        else
-          raise "Unexpected name format: #{raw}"
-        end
-      end
-
-      def record_identifier(design)
-        Identifier.new(filename: design.filename, issue_iid: design.issue.iid)
-      end
-
-      private
-
-      def can_read_designs?(project)
-        DeclarativePolicy.user_scope { can?(current_user, :read_design, project) }
-      end
-
-      def designs(issues, filenames)
-        DesignManagement::Design.on_issue(issues).with_filename(filenames)
-      end
-
-      def enabled?
-        Feature.enabled?(:design_management_reference_filter_gfm_pipeline)
-      end
-    end
-  end
-end

ee/lib/ee/banzai/pipeline/gfm_pipeline.rb

@@ -18,7 +18,6 @@ module EE
           def reference_filters
             [
               ::Banzai::Filter::EpicReferenceFilter,
-              ::Banzai::Filter::DesignReferenceFilter,
               *super
             ]
           end

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

-# frozen_string_literal: true
-
-require 'spec_helper'
-
-describe 'viewing issues with design references' do
-  include DesignManagementTestHelpers
-
-  let_it_be(:user) { create(:user) }
-  let_it_be(:project) { create(:project_empty_repo, :public) }
-  let_it_be(:design_issue) { create(:issue, project: project) }
-  let_it_be(:design_a) { create(:design, :with_file, issue: design_issue) }
-  let_it_be(:design_b) { create(:design, :with_file, issue: design_issue) }
-
-  let(:issue) { create(:issue, project: project, description: description) }
-
-  let(:description) do
-    <<~MD
-    Designs:
-
-    * #{design_a.to_reference(project)}
-    * #{design_b.to_reference(project)}
-    MD
-  end
-
-  before do
-    project.add_developer(user)
-    sign_in(user)
-  end
-
-  context 'design management is enabled' do
-    before do
-      enable_design_management
-    end
-
-    it 'shows the issue description' do
-      visit project_issue_path(project, issue)
-
-      expect(page).to have_link(design_a.to_reference)
-      expect(page).to have_link(design_b.to_reference)
-    end
-  end
-
-  context 'design management is disabled' do
-    before do
-      enable_design_management(false, false)
-    end
-
-    it 'shows the issue description' do
-      visit project_issue_path(project, issue)
-
-      expect(page).to have_link(issue.to_reference)
-      expect(page).not_to have_link(design_a.to_reference)
-      expect(page).not_to have_link(design_b.to_reference)
-    end
-  end
-end