Introduce CodeCoveragePresenter to PipelineArtifact

This MR introduces a new presenter class which will be used
to present data code coverage data to gitlab frontend. This
new architecture will allow us to scale to more file_type
easily in the near future.

app/models/ci/pipeline_artifact.rb

@@ -8,6 +8,7 @@ module Ci
     include UpdateProjectStatistics
     include Artifactable
     include FileStoreMounter
+    include Presentable
 
     FILE_STORE_SUPPORTED = [
       ObjectStorage::Store::LOCAL,
@@ -44,5 +45,9 @@ module Ci
     def self.find_with_code_coverage
       find_by(file_type: :code_coverage)
     end
+
+    def present
+      super(presenter_class: "Ci::PipelineArtifacts::#{self.file_type.camelize}Presenter".constantize)
+    end
   end
 end

app/presenters/ci/pipeline_artifacts/code_coverage_presenter.rb

+# frozen_string_literal: true
+
+module Ci
+  module PipelineArtifacts
+    class CodeCoveragePresenter < ProcessablePresenter
+      include Gitlab::Utils::StrongMemoize
+
+      def for_files(filenames)
+        coverage_files = raw_report["files"].select { |key| filenames.include?(key) }
+
+        { files: coverage_files }
+      end
+
+      private
+
+      def raw_report
+        strong_memoize(:raw_report) do
+          self.each_blob do |blob|
+            Gitlab::Json.parse(blob)
+          end
+        end
+      end
+    end
+  end
+end

app/services/ci/generate_coverage_reports_service.rb

@@ -12,7 +12,7 @@ module Ci
       {
         status: :parsed,
         key: key(base_pipeline, head_pipeline),
-        data: Gitlab::Ci::Pipeline::Artifact::CodeCoverage.new(head_pipeline.pipeline_artifacts.find_with_code_coverage).for_files(merge_request.new_paths)
+        data: head_pipeline.pipeline_artifacts.find_with_code_coverage.present.for_files(merge_request.new_paths)
       }
     rescue => e
       Gitlab::ErrorTracking.track_exception(e, project_id: project.id)

lib/gitlab/ci/pipeline/artifact/code_coverage.rb

-# frozen_string_literal: true
-
-module Gitlab
-  module Ci
-    module Pipeline
-      module Artifact
-        class CodeCoverage
-          include Gitlab::Utils::StrongMemoize
-
-          def initialize(pipeline_artifact)
-            @pipeline_artifact = pipeline_artifact
-          end
-
-          def for_files(filenames)
-            coverage_files = raw_report["files"].select { |key| filenames.include?(key) }
-
-            { files: coverage_files }
-          end
-
-          private
-
-          def raw_report
-            strong_memoize(:raw_report) do
-              @pipeline_artifact.each_blob do |blob|
-                Gitlab::Json.parse(blob)
-              end
-            end
-          end
-        end
-      end
-    end
-  end
-end

spec/models/ci/pipeline_artifact_spec.rb

@@ -109,4 +109,14 @@ RSpec.describe Ci::PipelineArtifact, type: :model do
       end
     end
   end
+
+  describe '#present' do
+    subject { coverage_report.present }
+
+    context 'when file_type is code_coverage' do
+      it 'uses code coverage presenter' do
+        expect(subject.present).to be_kind_of(Ci::PipelineArtifacts::CodeCoveragePresenter)
+      end
+    end
+  end
 end

spec/lib/gitlab/ci/pipeline/artifact/code_coverage_spec.rb → spec/presenters/ci/pipeline_artifacts/code_coverage_presenter_spec.rb

@@ -2,12 +2,13 @@
 
 require 'spec_helper'
 
-RSpec.describe Gitlab::Ci::Pipeline::Artifact::CodeCoverage do
+RSpec.describe Ci::PipelineArtifacts::CodeCoveragePresenter do
   let(:pipeline_artifact) { create(:ci_pipeline_artifact, :with_code_coverage_with_multiple_files) }
-  let(:code_coverage) { described_class.new(pipeline_artifact) }
+
+  subject(:presenter) { described_class.new(pipeline_artifact) }
 
   describe '#for_files' do
-    subject { code_coverage.for_files(filenames) }
+    subject { presenter.for_files(filenames) }
 
     context 'when code coverage has data' do
       context 'when filenames is empty' do

spec/services/ci/generate_coverage_reports_service_spec.rb

@@ -16,7 +16,8 @@ RSpec.describe Ci::GenerateCoverageReportsService do
       let!(:base_pipeline) { nil }
 
       it 'returns status and data', :aggregate_failures do
-        expect_next_instance_of(Gitlab::Ci::Pipeline::Artifact::CodeCoverage) do |instance|
+        expect_any_instance_of(Ci::PipelineArtifact) do |instance|
+          expect(instance).to receive(:present)
           expect(instance).to receive(:for_files).with(merge_request.new_paths).and_call_original
         end