Expand scope of coverage query

If job name is specified, allow for a successful execution of that
job to represent coverage even if it belongs to a failed pipeline.
If no job name is passed, we default back to the existing pipeline
coverage implementation.

changelogs/unreleased/more-coverage-badges.yml

+---
+title: Expand scope of coverage badge query to all successful builds
+merge_request: 45321
+author:
+type: changed

lib/gitlab/badge/coverage/report.rb

@@ -44,19 +44,13 @@ module Gitlab
           @pipeline ||= @project.ci_pipelines.latest_successful_for_ref(@ref)
         end
 
-        # rubocop: disable CodeReuse/ActiveRecord
         def raw_coverage
-          return unless pipeline
-
-          if @job.blank?
-            pipeline.coverage
+          if @job.present?
+            @project.builds.latest.success.for_ref(@ref).by_name(@job).order_id_desc.first&.coverage
           else
-            pipeline.builds
-              .find_by(name: @job)
-              .try(:coverage)
+            @project.ci_pipelines.latest_successful_for_ref(@ref)&.coverage
           end
         end
-        # rubocop: enable CodeReuse/ActiveRecord
       end
     end
   end

spec/lib/gitlab/badge/coverage/report_spec.rb

@@ -45,8 +45,8 @@ RSpec.describe Gitlab::Badge::Coverage::Report do
     context 'with no pipeline' do
       let(:pipeline) { nil }
 
-      it 'returns nil' do
-        expect(badge.status).to be_nil
+      it 'returns coverage from that job' do
+        expect(badge.status).to eq(40)
       end
     end