Add GFM issue support to search autocomplete

Enable GitHub Flavored Markdown support for issues to the
search autocomplete field. If the user is in the project
dashboard and enters GFM for an issue id, a link to that
issue will show up.

app/helpers/search_helper.rb

@@ -9,7 +9,8 @@ module SearchHelper
     resources_results = [
       recent_items_autocomplete(term),
       groups_autocomplete(term),
-      projects_autocomplete(term)
+      projects_autocomplete(term),
+      issue_autocomplete(term)
     ].flatten
 
     search_pattern = Regexp.new(Regexp.escape(term), "i")
@@ -172,6 +173,24 @@ module SearchHelper
   end
   # rubocop: enable CodeReuse/ActiveRecord
 
+  def issue_autocomplete(term)
+    return [] unless @project.present? && current_user && term =~ /\A#{Issue.reference_prefix}\d+\z/
+
+    iid = term.sub(Issue.reference_prefix, '').to_i
+    issue = @project.issues.find_by_iid(iid)
+    return [] unless issue && Ability.allowed?(current_user, :read_issue, issue)
+
+    [
+        {
+            category: 'In this project',
+            id: issue.id,
+            label: search_result_sanitize("#{issue.title} (#{issue.to_reference})"),
+            url: issue_path(issue),
+            avatar_url: issue.project.avatar_url || ''
+        }
+    ]
+  end
+
   # Autocomplete results for the current user's projects
   # rubocop: disable CodeReuse/ActiveRecord
   def projects_autocomplete(term, limit = 5)

changelogs/unreleased/233278-in-global-search-if-there-is-only-one-result-redirect-to-that-page.yml

+---
+title: Search Autocomplete add GFM support for issues
+merge_request: 44930
+author:
+type: changed

doc/user/search/index.md

@@ -211,6 +211,7 @@ You can also type in this search bar to see autocomplete suggestions for:
 - Recently viewed issues (try and type some word from the title of a recently viewed issue)
 - Recently viewed merge requests (try and type some word from the title of a recently viewed merge request)
 - Recently viewed epics (try and type some word from the title of a recently viewed epic)
+- [GitLab Flavored Markdown](../markdown.md#special-gitlab-references) (GFM) for issues within a project (try and type a GFM reference for an issue)
 
 ## Basic search
 

spec/helpers/search_helper_spec.rb

@@ -73,7 +73,7 @@ RSpec.describe SearchHelper do
         expect(result.keys).to match_array(%i[category id label url avatar_url])
       end
 
-      it 'includes the users recently viewed issues' do
+      it 'includes the users recently viewed issues', :aggregate_failures do
         recent_issues = instance_double(::Gitlab::Search::RecentIssues)
         expect(::Gitlab::Search::RecentIssues).to receive(:new).with(user: user).and_return(recent_issues)
         project1 = create(:project, :with_avatar, namespace: user.namespace)
@@ -104,7 +104,7 @@ RSpec.describe SearchHelper do
         })
       end
 
-      it 'includes the users recently viewed merge requests' do
+      it 'includes the users recently viewed merge requests', :aggregate_failures do
         recent_merge_requests = instance_double(::Gitlab::Search::RecentMergeRequests)
         expect(::Gitlab::Search::RecentMergeRequests).to receive(:new).with(user: user).and_return(recent_merge_requests)
         project1 = create(:project, :with_avatar, namespace: user.namespace)
@@ -145,10 +145,40 @@ RSpec.describe SearchHelper do
           @project = create(:project, :repository)
         end
 
-        it "includes project-specific sections" do
+        it "includes project-specific sections", :aggregate_failures do
           expect(search_autocomplete_opts("Files").size).to eq(1)
           expect(search_autocomplete_opts("Commits").size).to eq(1)
         end
+
+        context 'when user does not have access to project' do
+          it 'does not include issues by iid' do
+            issue = create(:issue, project: @project)
+            results = search_autocomplete_opts("\##{issue.iid}")
+
+            expect(results.count).to eq(0)
+          end
+        end
+
+        context 'when user has project access' do
+          before do
+            @project = create(:project, :repository, namespace: user.namespace)
+          end
+
+          it 'includes issues by iid', :aggregate_failures do
+            issue = create(:issue, project: @project, title: 'test title')
+            results = search_autocomplete_opts("\##{issue.iid}")
+
+            expect(results.count).to eq(1)
+
+            expect(results.first).to include({
+              category: 'In this project',
+              id: issue.id,
+              label: 'test title (#1)',
+              url: ::Gitlab::Routing.url_helpers.project_issue_path(issue.project, issue),
+              avatar_url: '' # project has no avatar
+            })
+          end
+        end
       end
     end