Add snowplow analytics for clicking search result

Add the relevant data attributes to track click events on search
results. This will help us track how useful our searches are for people
and help us detect when we may have made changes that impact the
usefulness of results.

app/views/projects/commits/_commit.html.haml

@@ -11,6 +11,7 @@
 - commit        = commit.present(current_user: current_user)
 - commit_status = commit.status_for(ref)
 - collapsible = local_assigns.fetch(:collapsible, true)
+- link_data_attrs = local_assigns.fetch(:link_data_attrs, {})
 
 - link = commit_path(project, commit, merge_request: merge_request)
 
@@ -26,7 +27,7 @@
       - if view_details && merge_request
         = link_to commit.title, project_commit_path(project, commit.id, merge_request_iid: merge_request.iid), class: ["commit-row-message item-title js-onboarding-commit-item", ("font-italic" if commit.message.empty?)]
       - else
-        = link_to_markdown_field(commit, :title, link, class: "commit-row-message item-title js-onboarding-commit-item #{"font-italic" if commit.message.empty?}")
+        = link_to_markdown_field(commit, :title, link, class: "commit-row-message item-title js-onboarding-commit-item #{"font-italic" if commit.message.empty?}", data: link_data_attrs)
       %span.commit-row-message.d-inline.d-sm-none
         ·
         = commit.short_id

app/views/search/results/_blob_data.html.haml

 .blob-result{ data: { qa_selector: 'result_item_content' } }
   .file-holder
     .js-file-title.file-title{ data: { qa_selector: 'file_title_content' } }
-      = link_to blob_link do
+      = link_to blob_link, data: {track_event: 'click_text', track_label: 'blob_path', track_property: 'search_result'} do
         %i.fa.fa-file
         %strong
           = search_blob_title(project, path)

app/views/search/results/_commit.html.haml

-= render 'projects/commits/commit', project: commit.project, commit: commit, ref: nil, show_project_name: @project.nil?
+= render 'projects/commits/commit', project: commit.project, commit: commit, ref: nil, show_project_name: @project.nil?, link_data_attrs: {track_event: 'click_text', track_label: 'commit_title', track_property: 'search_result'}

app/views/search/results/_issue.html.haml

 .search-result-row
   %h4
     = confidential_icon(issue)
-    = link_to project_issue_path(issue.project, issue) do
+    = link_to project_issue_path(issue.project, issue), data: {track_event: 'click_text', track_label: 'issue_title', track_property: 'search_result'} do
       %span.term.str-truncated= issue.title
     - if issue.closed?
       %span.badge.badge-danger.gl-ml-2= _("Closed")

app/views/search/results/_merge_request.html.haml

 .search-result-row
   %h4
-    = link_to project_merge_request_path(merge_request.target_project, merge_request) do
+    = link_to project_merge_request_path(merge_request.target_project, merge_request), data: {track_event: 'click_text', track_label: 'merge_request_title', track_property: 'search_result'} do
       %span.term.str-truncated= merge_request.title
     - if merge_request.merged?
       %span.badge.badge-primary.gl-ml-2= _("Merged")

app/views/search/results/_milestone.html.haml

 .search-result-row
   %h4
-    = link_to project_milestone_path(milestone.project, milestone) do
+    = link_to project_milestone_path(milestone.project, milestone), data: {track_event: 'click_text', track_label: 'milestone_title', track_property: 'search_result'} do
       %span.term.str-truncated= milestone.title
 
   - if milestone.description.present?

app/views/search/results/_note.html.haml

@@ -18,7 +18,7 @@
     - else
       %span #{note.noteable_type.titleize} ##{noteable_identifier}
       ·
-      = link_to note.noteable.title, note_url
+      = link_to note.noteable.title, note_url, data: {track_event: 'click_text', track_label: 'noteable_title', track_property: 'search_result'}
 
   .note-search-result
     .term

spec/views/search/_results.html.haml_spec.rb

@@ -3,13 +3,16 @@
 require 'spec_helper'
 
 RSpec.describe 'search/_results' do
+  let(:search_objects) { Issue.page(1).per(2) }
+  let(:scope) { 'issues' }
+
   before do
     controller.params[:action] = 'show'
 
     create_list(:issue, 3)
 
-    @search_objects = Issue.page(1).per(2)
-    @scope = 'issues'
+    @search_objects = search_objects
+    @scope = scope
     @search_term = 'foo'
   end
 
@@ -30,4 +33,28 @@ RSpec.describe 'search/_results' do
       expect(rendered).not_to have_content(/Showing .* of .*/)
     end
   end
+
+  context 'rendering all types of search results' do
+    let_it_be(:project) { create(:project, :repository, :wiki_repo) }
+    let_it_be(:issue) { create(:issue, project: project, title: '*') }
+    let_it_be(:merge_request) { create(:merge_request, title: '*', source_project: project, target_project: project) }
+    let_it_be(:milestone) { create(:milestone, title: '*', project: project) }
+    let_it_be(:note) { create(:discussion_note_on_issue, project: project, note: '*') }
+    let_it_be(:wiki_blob) { create(:wiki_page, project: project, content: '*') }
+    let_it_be(:user) { create(:admin) }
+
+    %w[issues blobs notes wiki_blobs merge_requests milestones].each do |search_scope|
+      context "when scope is #{search_scope}" do
+        let(:scope) { search_scope }
+        let(:search_objects) { Gitlab::ProjectSearchResults.new(user, '*', project: project).objects(scope) }
+
+        it 'renders the click text event tracking attributes' do
+          render
+
+          expect(rendered).to have_selector('[data-track-event=click_text]')
+          expect(rendered).to have_selector('[data-track-property=search_result]')
+        end
+      end
+    end
+  end
 end