Add design reference filter

This reference filter only operates on URLs.

app/models/design_management/design.rb

@@ -126,68 +126,23 @@ module DesignManagement
     #   #12["filename with [] in it.jpg"]
     def to_reference(from = nil, full: false)
       infix = full ? '/designs' : ''
-      totally_simple = %r{ \A #{self.class.simple_file_name} \z }x
-      safe_name = if totally_simple.match?(filename)
-                    filename
-                  elsif filename =~ /[<>]/
-                    %Q{base64:#{Base64.strict_encode64(filename)}}
-                  else
-                    escaped = filename.gsub(%r{[\\"]}) { |x| "\\#{x}" }
-                    %Q{"#{escaped}"}
-                  end
+      safe_name = Sanitize.fragment(filename)
 
       "#{issue.to_reference(from, full: full)}#{infix}[#{safe_name}]"
     end
 
     def self.reference_pattern
-      @reference_pattern ||= begin
-        # Filenames can be escaped with double quotes to name filenames
-        # that include square brackets, or other special characters
-        %r{
-          #{Issue.reference_pattern}
-          (\/designs)?
-          \[
-            (?<design> #{simple_file_name} | #{quoted_file_name} | #{base_64_encoded_name})
-          \]
-        }x
-      end
-    end
-
-    def self.simple_file_name
-      %r{
-          (?<simple_file_name>
-           ( \w | [_:,'-] | \. | \s )+
-           \.
-           \w+
-          )
-      }x
-    end
-
-    def self.base_64_encoded_name
-      %r{
-          base64:
-          (?<base_64_encoded_name>
-           [A-Za-z0-9+\n]+
-           =?
-          )
-      }x
-    end
-
-    def self.quoted_file_name
-      %r{
-          "
-          (?<escaped_filename>
-            (\\ \\ | \\ " | [^"\\])+
-          )
-          "
-      }x
+      # no-op: We only support link_reference_pattern parsing
     end
 
     def self.link_reference_pattern
       @link_reference_pattern ||= begin
-        exts = SAFE_IMAGE_EXT + DANGEROUS_IMAGE_EXT
         path_segment = %r{issues/#{Gitlab::Regex.issue}/designs}
-        filename_pattern = %r{(?<simple_file_name>[a-z0-9_=-]+\.(#{exts.join('|')}))}i
+        ext = Regexp.new(Regexp.union(SAFE_IMAGE_EXT + DANGEROUS_IMAGE_EXT).source, Regexp::IGNORECASE)
+        valid_char = %r{[^/\s]} # any char that is not a forward slash or whitespace
+        filename_pattern = %r{
+          (?<url_filename> #{valid_char}+ \. #{ext})
+        }x
 
         super(path_segment, filename_pattern)
       end

changelogs/unreleased/ajk-design-ref-filter.yml

+---
+title: Enable GitLab-Flavored Markdown processing for design links
+merge_request: 32446
+author:
+type: added

doc/user/markdown.md

@@ -442,7 +442,7 @@ In addition to this, links to some objects are also recognized and formatted. So
 
 - Comments on issues: `"https://gitlab.com/gitlab-org/gitlab/-/issues/1234#note_101075757"`, which will be rendered as `#1234 (note1)`
 - The issues designs tab: `"https://gitlab.com/gitlab-org/gitlab/-/issues/1234/designs"`, which will be rendered as `#1234 (designs)`.
-  **(PREMIUM)**
+- Links to individual designs: `"https://gitlab.com/gitlab-org/gitlab/-/issues/1234/designs/layout.png"`, which will be rendered as `#1234[layout.png]`.
 
 ### Task lists
 

doc/user/project/issues/design_management.md

@@ -176,3 +176,44 @@ Different discussions have different pin numbers:
 
 From GitLab 12.5 on, new discussions will be outputted to the issue activity,
 so that everyone involved can participate in the discussion.
+
+## Referring to designs in Markdown
+
+> - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/217160) in **GitLab 13.1**.
+> - It is deployed behind a feature flag, disabled by default.
+> - It is disabled on GitLab.com.
+> - It is not recommended for production use.
+> - To use it in GitLab self-managed instances, ask a GitLab administrator to [enable it](#enable-or-disable-design-references-core-only). **(CORE ONLY)**
+
+We support referring to designs in [Markdown](../../markdown.md), which is available
+throughout the application, including in merge request and issue descriptions, in discussions and comments, and in wiki pages.
+
+At present, full URL references are supported. For example, if we refer to a design
+somewhere with:
+
+```markdown
+See http://gitlab.com/your-group/your-project/-/issues/123/designs/homescreen.png
+```
+
+This will be rendered as:
+
+> See [#123[homescreen.png]](http://gitlab.com/your-group/your-project/-/issues/123/designs/homescreen.png)
+
+### Enable or disable design references **(CORE ONLY)**
+
+Design reference parsing is under development and not ready for production use. It is
+deployed behind a feature flag that is **disabled by default**.
+[GitLab administrators with access to the GitLab Rails console](../../../administration/feature_flags.md)
+can enable it for your instance.
+
+To enable it:
+
+```ruby
+Feature.enable(:design_management_reference_filter_gfm_pipeline)
+```
+
+To disable it:
+
+```ruby
+Feature.disable(:design_management_reference_filter_gfm_pipeline)
+```

lib/banzai/filter/design_reference_filter.rb

+# frozen_string_literal: true
+
+module Banzai
+  module Filter
+    class DesignReferenceFilter < AbstractReferenceFilter
+      FEATURE_FLAG = :design_management_reference_filter_gfm_pipeline
+
+      class Identifier
+        include Comparable
+        attr_reader :issue_iid, :filename
+
+        def initialize(issue_iid:, filename:)
+          @issue_iid = issue_iid
+          @filename = filename
+        end
+
+        def as_composite_id(id_for_iid)
+          id = id_for_iid[issue_iid]
+          return unless id
+
+          { issue_id: id, filename: filename }
+        end
+
+        def <=>(other)
+          return unless other.is_a?(Identifier)
+
+          [issue_iid, filename] <=> [other.issue_iid, other.filename]
+        end
+        alias_method :eql?, :==
+
+        def hash
+          [issue_iid, filename].hash
+        end
+      end
+
+      self.reference_type = :design
+
+      # This filter must be enabled by setting the
+      # design_management_reference_filter_gfm_pipeline flag
+      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 project.design_management_enabled?
+
+        iids        = identifiers.map(&:issue_iid).to_set
+        issues      = project.issues.where(iid: iids)
+        id_for_iid  = issues.index_by(&:iid).transform_values(&:id)
+        issue_by_id = issues.index_by(&:id)
+
+        designs(identifiers, id_for_iid).each do |d|
+          issue = issue_by_id[d.issue_id]
+          # optimisation: assign values we have already fetched
+          d.project = project
+          d.issue = issue
+        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 = match_data[:url_filename]
+        iid = match_data[:issue].to_i
+        Identifier.new(filename: CGI.unescape(filename), issue_iid: iid)
+      end
+
+      def record_identifier(design)
+        Identifier.new(filename: design.filename, issue_iid: design.issue.iid)
+      end
+
+      private
+
+      def designs(identifiers, id_for_iid)
+        identifiers
+          .map { |identifier| identifier.as_composite_id(id_for_iid) }
+          .compact
+          .in_groups_of(100, false) # limitation of by_issue_id_and_filename, so we batch
+          .flat_map { |ids| DesignManagement::Design.by_issue_id_and_filename(ids) }
+      end
+
+      def enabled?
+        Feature.enabled?(FEATURE_FLAG, parent)
+      end
+    end
+  end
+end

lib/banzai/filter/issue_reference_filter.rb

@@ -44,7 +44,7 @@ module Banzai
       end
 
       def read_designs?(issue)
-        Ability.allowed?(current_user, :read_design, issue)
+        issue.project.design_management_enabled?
       end
     end
   end

lib/banzai/pipeline/gfm_pipeline.rb

@@ -56,6 +56,7 @@ module Banzai
         [
           Filter::UserReferenceFilter,
           Filter::ProjectReferenceFilter,
+          Filter::DesignReferenceFilter,
           Filter::IssueReferenceFilter,
           Filter::ExternalIssueReferenceFilter,
           Filter::MergeRequestReferenceFilter,

spec/features/projects/issues/design_management/user_links_to_designs_in_issue_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe 'viewing issues with design references' do
+  include DesignManagementTestHelpers
+
+  let_it_be(:public_project) { create(:project_empty_repo, :public) }
+  let_it_be(:private_project) { create(:project_empty_repo) }
+
+  let(:user) { create(:user) }
+  let(:design_issue) { create(:issue, project: project) }
+  let(:design_a) { create(:design, :with_file, issue: design_issue) }
+  let(:design_b) { create(:design, :with_file, issue: design_issue) }
+  let(:issue_ref) { design_issue.to_reference(public_project) }
+  let(:design_ref_a) { design_a.to_reference(public_project) }
+  let(:design_ref_b) { design_b.to_reference(public_project) }
+  let(:design_tab_ref) { "#{issue_ref} (designs)" }
+
+  let(:description) do
+    <<~MD
+    The designs I mentioned:
+
+    * #{url_for_designs(design_issue)}
+    * #{url_for_design(design_a)}
+    * #{url_for_design(design_b)}
+    MD
+  end
+
+  def visit_page_with_design_references
+    public_issue = create(:issue, project: public_project, description: description)
+    visit project_issue_path(public_issue.project, public_issue)
+  end
+
+  shared_examples 'successful use of design link references' do
+    before do
+      enable_design_management
+    end
+
+    it 'shows the issue description and design references', :aggregate_failures do
+      visit_page_with_design_references
+
+      expect(page).to have_text('The designs I mentioned')
+      expect(page).to have_link(design_tab_ref)
+      expect(page).to have_link(design_ref_a)
+      expect(page).to have_link(design_ref_b)
+    end
+  end
+
+  context 'the user has access to a public project' do
+    let(:project) { public_project }
+
+    it_behaves_like 'successful use of design link references'
+  end
+
+  context 'the user does not have access to a private project' do
+    let(:project) { private_project }
+
+    it 'redacts inaccessible design references', :aggregate_failures do
+      visit_page_with_design_references
+
+      expect(page).to have_text('The designs I mentioned')
+      expect(page).not_to have_link(issue_ref)
+      expect(page).not_to have_link(design_tab_ref)
+      expect(page).not_to have_link(design_ref_a)
+      expect(page).not_to have_link(design_ref_b)
+    end
+  end
+
+  context 'the user has access to a private project' do
+    let(:project) { private_project }
+
+    before do
+      project.add_developer(user)
+      sign_in(user)
+    end
+
+    it_behaves_like 'successful use of design link references'
+
+    context 'design management is entirely disabled' do
+      it 'processes design links as issue references', :aggregate_failures do
+        enable_design_management(false)
+
+        visit_page_with_design_references
+
+        expect(page).to have_text('The designs I mentioned')
+        expect(page).to have_link(issue_ref)
+        expect(page).not_to have_link(design_tab_ref)
+        expect(page).not_to have_link(design_ref_a)
+        expect(page).not_to have_link(design_ref_b)
+      end
+    end
+
+    context 'design management is enabled, but the filter is disabled globally' do
+      before do
+        enable_design_management
+        stub_feature_flags(
+          Banzai::Filter::DesignReferenceFilter::FEATURE_FLAG => false
+        )
+      end
+
+      it 'processes design tab links successfully, and design references as issue references', :aggregate_failures do
+        visit_page_with_design_references
+
+        expect(page).to have_text('The designs I mentioned')
+        expect(page).to have_link(design_tab_ref)
+        expect(page).to have_link(issue_ref)
+        expect(page).not_to have_link(design_ref_a)
+        expect(page).not_to have_link(design_ref_b)
+      end
+    end
+
+    context 'design management is enabled, and the filter is enabled for the current project' do
+      before do
+        stub_feature_flags(
+          Banzai::Filter::DesignReferenceFilter::FEATURE_FLAG => public_project
+        )
+      end
+
+      it_behaves_like 'successful use of design link references'
+    end
+  end
+end

spec/lib/banzai/filter/design_reference_filter_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Banzai::Filter::DesignReferenceFilter do
+  include FilterSpecHelper
+  include DesignManagementTestHelpers
+
+  let_it_be(:issue)         { create(:issue, iid: 10) }
+  let_it_be(:issue_proj_2)  { create(:issue, iid: 20) }
+  let_it_be(:issue_b)       { create(:issue, project: issue.project) }
+  let_it_be(:developer)     { create(:user, developer_projects: [issue.project, issue_proj_2.project]) }
+  let_it_be(:design_a)      { create(:design, :with_versions, issue: issue) }
+  let_it_be(:design_b)      { create(:design, :with_versions, issue: issue_b) }
+  let_it_be(:design_proj_2) { create(:design, :with_versions, issue: issue_proj_2) }
+  let_it_be(:project_with_no_lfs) { create(:project, :public, lfs_enabled: false) }
+
+  let(:design)       { design_a }
+  let(:project)      { issue.project }
+  let(:project_2)    { issue_proj_2.project }
+  let(:reference)    { design.to_reference }
+  let(:design_url)   { url_for_design(design) }
+  let(:input_text)   { "Added #{design_url}" }
+  let(:doc)          { process_doc(input_text) }
+  let(:current_user) { developer }
+
+  before do
+    enable_design_management
+  end
+
+  shared_examples 'a no-op filter' do
+    it 'does nothing' do
+      expect(process(input_text)).to eq(baseline(input_text).to_html)
+    end
+  end
+
+  shared_examples 'a good link reference' do
+    let(:link) { doc.css('a').first }
+    let(:href) { url_for_design(design) }
+    let(:title) { design.filename }
+
+    it 'produces a good link', :aggregate_failures do
+      expect(link.attr('href')).to eq(href)
+      expect(link.attr('title')).to eq(title)
+      expect(link.attr('class')).to eq('gfm gfm-design has-tooltip')
+      expect(link.attr('data-project')).to eq(design.project.id.to_s)
+      expect(link.attr('data-issue')).to eq(design.issue.id.to_s)
+      expect(link.attr('data-original')).to eq(href)
+      expect(link.attr('data-reference-type')).to eq('design')
+      expect(link.text).to eq(design.to_reference(project))
+    end
+  end
+
+  describe '.call' do
+    it 'requires project context' do
+      expect { described_class.call('') }.to raise_error(ArgumentError, /:project/)
+    end
+  end
+
+  it 'does not error when we add redaction to the pipeline' do
+    enable_design_management
+
+    res = reference_pipeline(redact: true).to_document(input_text)
+
+    expect(res.css('a').first).to be_present
+  end
+
+  describe '#call' do
+    describe 'feature flags' do
+      context 'design management is not enabled' do
+        before do
+          enable_design_management(false)
+        end
+
+        it_behaves_like 'a no-op filter'
+      end
+
+      context 'design reference filter is not enabled' do
+        before do
+          stub_feature_flags(described_class::FEATURE_FLAG => false)
+        end
+
+        it_behaves_like 'a no-op filter'
+
+        it 'issues no queries' do
+          expect { process(input_text) }.not_to exceed_query_limit(0)
+        end
+      end
+
+      context 'the filter is enabled for the context project' do
+        before do
+          stub_feature_flags(described_class::FEATURE_FLAG => project)
+        end
+
+        it_behaves_like 'a good link reference'
+      end
+    end
+  end
+
+  %w(pre code a style).each do |elem|
+    context "wrapped in a <#{elem}/>" do
+      let(:input_text) { "<#{elem}>Design #{url_for_design(design)}</#{elem}>" }
+
+      it_behaves_like 'a no-op filter'
+    end
+  end
+
+  describe '.identifier' do
+    where(:filename) do
+      [
+        ['simple.png'],
+        ['SIMPLE.PNG'],
+        ['has spaces.png'],
+        ['has-hyphen.jpg'],
+        ['snake_case.svg'],
+        ['has "quotes".svg'],
+        ['has <special> characters [o].svg']
+      ]
+    end
+
+    with_them do
+      let(:design) { build(:design, issue: issue, filename: filename) }
+      let(:url) { url_for_design(design) }
+      let(:pattern) { described_class.object_class.link_reference_pattern }
+      let(:parsed) do
+        m = pattern.match(url)
+        described_class.identifier(m) if m
+      end
+
+      it 'can parse the reference' do
+        expect(parsed).to have_attributes(
+          filename: filename,
+          issue_iid: issue.iid
+        )
+      end
+    end
+  end
+
+  describe 'static properties' do
+    specify do
+      expect(described_class).to have_attributes(
+        object_sym: :design,
+        object_class: ::DesignManagement::Design
+      )
+    end
+  end
+
+  describe '#data_attributes_for' do
+    let(:subject) { filter_instance.data_attributes_for(input_text, project, design) }
+
+    specify do
+      is_expected.to include(issue: design.issue_id,
+                             original: input_text,
+                             project: project.id,
+                             design: design.id)
+    end
+  end
+
+  context 'a design with a quoted filename' do
+    let(:filename) { %q{A "very" good file.png} }
+    let(:design) { create(:design, :with_versions, issue: issue, filename: filename) }
+
+    it 'links to the design' do
+      expect(doc.css('a').first.attr('href'))
+        .to eq url_for_design(design)
+    end
+  end
+
+  context 'internal reference' do
+    it_behaves_like 'a reference containing an element node'
+
+    context 'the reference is valid' do
+      it_behaves_like 'a good link reference'
+
+      context 'the filename needs to be escaped' do
+        where(:filename) do
+          [
+            ['with some spaces.png'],
+            ['with <script>console.log("pwded")<%2Fscript>.png']
+          ]
+        end
+
+        with_them do
+          let(:design) { create(:design, :with_versions, filename: filename, issue: issue) }
+          let(:link) { doc.css('a').first }
+
+          it 'replaces the content with the reference, but keeps the link', :aggregate_failures do
+            expect(doc.text).to eq(CGI.unescapeHTML("Added #{design.to_reference}"))
+            expect(link.attr('title')).to eq(design.filename)
+            expect(link.attr('href')).to eq(design_url)
+          end
+        end
+      end
+    end
+
+    context 'the reference is to a non-existant design' do
+      let(:design_url) { url_for_design(build(:design, issue: issue)) }
+
+      it_behaves_like 'a no-op filter'
+    end
+
+    context 'design management is disabled for the referenced project' do
+      let(:public_issue) { create(:issue, project: project_with_no_lfs) }
+      let(:design) { create(:design, :with_versions, issue: public_issue) }
+
+      it_behaves_like 'a no-op filter'
+    end
+  end
+
+  describe 'link pattern' do
+    let(:reference) { url_for_design(design) }
+
+    it 'matches' do
+      expect(reference).to match(DesignManagement::Design.link_reference_pattern)
+    end
+  end
+
+  context 'cross-project / cross-namespace complete reference' do
+    let(:design) { design_proj_2 }
+
+    it_behaves_like 'a reference containing an element node'
+
+    it_behaves_like 'a good link reference'
+
+    it 'links to a valid reference' do
+      expect(doc.css('a').first.attr('href')).to eq(design_url)
+    end
+
+    context 'design management is disabled for that project' do
+      let(:design) { create(:design, project: project_with_no_lfs) }
+
+      it_behaves_like 'a no-op filter'
+    end
+
+    it 'link has valid text' do
+      ref = "#{design.project.full_path}##{design.issue.iid}[#{design.filename}]"
+
+      expect(doc.css('a').first.text).to eql(ref)
+    end
+
+    it 'includes default classes' do
+      expect(doc.css('a').first.attr('class')).to eq 'gfm gfm-design has-tooltip'
+    end
+
+    context 'the reference is invalid' do
+      let(:design_url) { url_for_design(design).gsub(/jpg/, 'gif') }
+
+      it_behaves_like 'a no-op filter'
+    end
+  end
+
+  describe 'performance' do
+    it 'is linear in the number of projects with design management enabled each design refers to' do
+      design_c = build(:design, :with_versions, issue: issue)
+      design_d = build(:design, :with_versions, issue: issue_b)
+      design_e = build(:design, :with_versions, issue: build_stubbed(:issue, project: project_2))
+
+      one_ref_per_project = <<~MD
+      Design #{url_for_design(design_a)}, #{url_for_design(design_proj_2)}
+      MD
+
+      multiple_references = <<~MD
+      Designs that affect the count:
+       * #{url_for_design(design_a)}
+       * #{url_for_design(design_b)}
+       * #{url_for_design(design_c)}
+       * #{url_for_design(design_d)}
+       * #{url_for_design(design_proj_2)}
+       * #{url_for_design(design_e)}
+
+     Things that do not affect the count:
+       * #{url_for_design(build_stubbed(:design, project: project_with_no_lfs))}
+       * #{url_for_designs(issue)}
+       * #1[not a valid reference.gif]
+      MD
+
+      baseline = ActiveRecord::QueryRecorder.new { process(one_ref_per_project) }
+
+      # each project mentioned requires 2 queries:
+      #
+      #  * SELECT "issues".* FROM "issues" WHERE "issues"."project_id" = 1 AND ...
+      #      :in `parent_records'*/
+      #  * SELECT "_designs".* FROM "_designs"
+      #      WHERE (issue_id = ? AND filename = ?) OR ...
+      #      :in `parent_records'*/
+      #
+      # In addition there is a 1 query overhead for all the projects at the
+      # start. Currently, the baseline for 2 projects is `2 * 2 + 1 = 5` queries
+      #
+      expect { process(multiple_references) }.not_to exceed_query_limit(baseline.count)
+    end
+  end
+
+  private
+
+  def process_doc(text)
+    reference_filter(text, project: project)
+  end
+
+  def baseline(text)
+    null_filter(text, project: project)
+  end
+
+  def process(text)
+    process_doc(text).to_html
+  end
+end

spec/lib/banzai/filter/issue_reference_filter_spec.rb

@@ -374,6 +374,16 @@ describe Banzai::Filter::IssueReferenceFilter do
       expect(link.attr('href')).to eq(designs_tab_url)
       expect(link.text).to eq("#{issue.to_reference} (designs)")
     end
+
+    context 'design management is not available' do
+      before do
+        enable_design_management(false)
+      end
+
+      it 'links to the issue, but not to the designs tab' do
+        expect(link.text).to eq(issue.to_reference)
+      end
+    end
   end
 
   context 'group context' do

spec/models/design_management/design_spec.rb

@@ -460,38 +460,6 @@ describe DesignManagement::Design do
       it 'uses the simple format' do
         expect(reference).to eq "#1[homescreen.jpg]"
       end
-
-      context 'when the filename contains spaces, hyphens, periods, single-quotes, underscores and colons' do
-        let(:filename) { %q{a complex filename: containing - _ : etc., but still 'simple'.gif} }
-
-        it 'uses the simple format' do
-          expect(reference).to eq "#1[#{filename}]"
-        end
-      end
-
-      context 'when the filename contains HTML angle brackets' do
-        let(:filename) { 'a <em>great</em> filename.jpg' }
-
-        it 'uses Base64 encoding' do
-          expect(reference).to eq "#1[base64:#{Base64.strict_encode64(filename)}]"
-        end
-      end
-
-      context 'when the filename contains quotation marks' do
-        let(:filename) { %q{a "great" filename.jpg} }
-
-        it 'uses enclosing quotes, with backslash encoding' do
-          expect(reference).to eq %q{#1["a \"great\" filename.jpg"]}
-        end
-      end
-
-      context 'when the filename contains square brackets' do
-        let(:filename) { %q{a [great] filename.jpg} }
-
-        it 'uses enclosing quotes' do
-          expect(reference).to eq %q{#1["a [great] filename.jpg"]}
-        end
-      end
     end
 
     context 'when full is true' do
@@ -525,31 +493,55 @@ describe DesignManagement::Design do
   end
 
   describe 'reference_pattern' do
-    let(:match) { described_class.reference_pattern.match(ref) }
-    let(:ref) { design.to_reference }
-    let(:design) { build(:design, filename: filename) }
+    it 'is nil' do
+      expect(described_class.reference_pattern).to be_nil
+    end
+  end
+
+  describe 'link_reference_pattern' do
+    it 'is not nil' do
+      expect(described_class.link_reference_pattern).not_to be_nil
+    end
 
-    context 'simple_file_name' do
-      let(:filename) { 'simple-file-name.jpg' }
+    it 'does not match the designs tab' do
+      expect(described_class.link_reference_pattern).not_to match(url_for_designs(issue))
+    end
 
-      it 'matches :simple_file_name' do
-        expect(match[:simple_file_name]).to eq(filename)
+    where(:ext) do
+      (described_class::SAFE_IMAGE_EXT + described_class::DANGEROUS_IMAGE_EXT).flat_map do |ext|
+        [[ext], [ext.upcase]]
       end
     end
 
-    context 'quoted_file_name' do
-      let(:filename) { 'simple "file" name.jpg' }
+    with_them do
+      let(:filename) { "my-file.#{ext}" }
+      let(:design) { build(:design, filename: filename) }
+      let(:url) { url_for_design(design) }
+      let(:captures) { described_class.link_reference_pattern.match(url)&.named_captures }
+
+      it 'matches the URL' do
+        expect(captures).to include(
+          'url_filename' => filename,
+          'issue' => design.issue.iid.to_s,
+          'namespace' => design.project.namespace.to_param,
+          'project' => design.project.name
+        )
+      end
+
+      context 'the file needs to be encoded' do
+        let(:filename) { "my file.#{ext}" }
 
-      it 'matches :simple_file_name' do
-        expect(match[:escaped_filename].gsub(/\\"/, '"')).to eq(filename)
+        it 'extracts the encoded filename' do
+          expect(captures).to include('url_filename' => 'my%20file.' + ext)
         end
       end
 
-    context 'Base64 name' do
-      let(:filename) { '<>.png' }
+      context 'the file is all upper case' do
+        let(:filename) { "file.#{ext}".upcase }
 
-      it 'matches base_64_encoded_name' do
-        expect(Base64.decode64(match[:base_64_encoded_name])).to eq(filename)
+        it 'extracts the encoded filename' do
+          expect(captures).to include('url_filename' => filename)
+        end
       end
     end
   end

spec/support/helpers/design_management_test_helpers.rb

 # frozen_string_literal: true
 
 module DesignManagementTestHelpers
-  def enable_design_management(enabled = true, ref_filter = true)
+  def enable_design_management(enabled = true)
     stub_lfs_setting(enabled: enabled)
-    stub_feature_flags(design_management_reference_filter_gfm_pipeline: ref_filter)
   end
 
   def delete_designs(*designs)

spec/support/helpers/filter_spec_helper.rb

@@ -56,14 +56,11 @@ module FilterSpecHelper
     pipeline.call(body)
   end
 
-  def reference_pipeline(context = {})
+  def reference_pipeline(filter: described_class, **context)
     context.reverse_merge!(project: project) if defined?(project)
     context.reverse_merge!(current_user: current_user) if defined?(current_user)
 
-    filters = [
-      Banzai::Filter::AutolinkFilter,
-      described_class
-    ]
+    filters = [Banzai::Filter::AutolinkFilter, filter].compact
 
     redact = context.delete(:redact)
     filters.push(Banzai::Filter::ReferenceRedactorFilter) if redact
@@ -75,8 +72,13 @@ module FilterSpecHelper
     reference_pipeline(context).call(body)
   end
 
-  def reference_filter(html, context = {})
-    reference_pipeline(context).to_document(html)
+  def reference_filter(text, context = {})
+    reference_pipeline(**context).to_document(text)
+  end
+
+  # Use to test no-ops
+  def null_filter(text, context = {})
+    reference_pipeline(filter: nil, **context).to_document(text)
   end
 
   # Modify a String reference to make it invalid