Added evidence json to release controller

Added evidence method to Projects::ReleaseController.
Added test accordingly.
Added new route.

app/controllers/projects/releases_controller.rb

@@ -20,6 +20,15 @@ class Projects::ReleasesController < Projects::ApplicationController
     end
   end
 
+  def evidence
+    summary = release.evidence_summary || {}
+    respond_to do |format|
+      format.json do
+        render json: summary
+      end
+    end
+  end
+
   protected
 
   def releases

app/models/release.rb

@@ -77,6 +77,10 @@ class Release < ApplicationRecord
     evidence&.summary_sha
   end
 
+  def evidence_summary
+    evidence&.summary
+  end
+
   private
 
   def actual_sha

config/routes/project.rb

@@ -179,7 +179,12 @@ constraints(::Constraints::ProjectUrlConstrainer.new) do
           end
         end
 
-        resources :releases, only: [:index, :edit], param: :tag, constraints: { tag: %r{[^/]+} }
+        resources :releases, only: [:index, :edit], param: :tag, constraints: { tag: %r{[^/]+} } do
+          member do
+            get :evidence
+          end
+        end
+
         resources :starrers, only: [:index]
         resources :forks, only: [:index, :new, :create]
         resources :group_links, only: [:index, :create, :update, :destroy], constraints: { id: /\d+/ }

spec/controllers/projects/releases_controller_spec.rb

@@ -166,6 +166,40 @@ describe Projects::ReleasesController do
     end
   end
 
+  describe 'GET #evidence' do
+    let!(:release) { create(:release, project: project) }
+    let(:tag) { CGI.escape(release.tag) }
+    let(:format) { :json }
+
+    subject do
+      get :evidence, params: {
+        namespace_id: project.namespace,
+        project_id: project,
+        tag: tag,
+        format: format
+      }
+    end
+
+    before do
+      sign_in(user)
+      CreateEvidenceWorker.new.perform(release.id)
+    end
+
+    it 'returns the correct evidence summary as a json' do
+      subject
+      expect(response.body).to eq(release.evidence.summary.to_json)
+    end
+
+    context 'when the release was created before evidence existed' do
+      it 'returns an empty json' do
+        release.evidence.destroy
+        subject
+
+        expect(response.body).to eq('{}')
+      end
+    end
+  end
+
   private
 
   def get_index