Add signature badge to diffs/commit_item

**Notes:**
- Also exposes commit.signature_html in diffs.json

app/assets/javascripts/diffs/components/commit_item.vue

@@ -102,6 +102,10 @@ export default {
         ></pre>
       </div>
       <div class="commit-actions flex-row d-none d-sm-flex">
+        <div
+          v-if="commit.signatureHtml"
+          v-html="commit.signatureHtml"
+        ></div>
         <div class="commit-sha-group">
           <div
             class="label label-monospace"

app/controllers/projects/merge_requests/diffs_controller.rb

@@ -25,7 +25,13 @@ class Projects::MergeRequests::DiffsController < Projects::MergeRequests::Applic
 
     @diffs.write_cache
 
-    render json: DiffsSerializer.new(current_user: current_user, project: @merge_request.project).represent(@diffs, additional_attributes)
+    request = {
+      current_user: current_user,
+      project: @merge_request.project,
+      render: ->(partial, locals) { view_to_html_string(partial, locals) }
+    }
+
+    render json: DiffsSerializer.new(request).represent(@diffs, additional_attributes)
   end
 
   def define_diff_vars

app/serializers/commit_entity.rb

@@ -25,4 +25,14 @@ class CommitEntity < API::Entities::Commit
   expose :title_html, if: { type: :full } do |commit|
     markdown_field(commit, :title)
   end
+
+  expose :signature_html, if: { type: :full } do |commit|
+    render('projects/commit/_signature', signature: commit.signature) if commit.has_signature?
+  end
+
+  def render(*args)
+    return unless request.respond_to?(:render) && request.render.respond_to?(:call)
+
+    request.render.call(*args)
+  end
 end

spec/javascripts/diffs/components/commit_item_spec.js

@@ -9,6 +9,7 @@ import getDiffWithCommit from '../mock_data/diff_with_commit';
 const TEST_AUTHOR_NAME = 'test';
 const TEST_AUTHOR_EMAIL = 'test+test@gitlab.com';
 const TEST_AUTHOR_GRAVATAR = `${TEST_HOST}/avatar/test?s=36`;
+const TEST_SIGNATURE_HTML = '<a>Legit commit</a>';
 
 const getTitleElement = vm => vm.$el.querySelector('.commit-row-message.item-title');
 const getDescElement = vm => vm.$el.querySelector('pre.commit-row-description');
@@ -16,6 +17,7 @@ const getDescExpandElement = vm => vm.$el.querySelector('.commit-content .text-e
 const getShaElement = vm => vm.$el.querySelector('.commit-sha-group');
 const getAvatarElement = vm => vm.$el.querySelector('.user-avatar-link');
 const getCommitterElement = vm => vm.$el.querySelector('.commiter');
+const getCommitActionsElement = vm => vm.$el.querySelector('.commit-actions');
 
 describe('diffs/components/commit_widget', () => {
   const Component = Vue.extend(CommitItem);
@@ -125,4 +127,20 @@ describe('diffs/components/commit_widget', () => {
       expect(nameElement).toHaveText(TEST_AUTHOR_NAME);
     });
   });
+
+  describe('with signature', () => {
+    beforeEach(done => {
+      vm.commit.signatureHtml = TEST_SIGNATURE_HTML;
+
+      vm.$nextTick()
+        .then(done)
+        .catch(done.fail);
+    });
+
+    it('renders signature html', () => {
+      const actionsElement = getCommitActionsElement(vm);
+
+      expect(actionsElement).toContainHtml(TEST_SIGNATURE_HTML);
+    });
+  });
 });

spec/serializers/commit_entity_spec.rb

 require 'spec_helper'
 
 describe CommitEntity do
+  SIGNATURE_HTML = 'TEST'.freeze
+
   let(:entity) do
     described_class.new(commit, request: request)
   end
-
   let(:request) { double('request') }
   let(:project) { create(:project, :repository) }
   let(:commit) { project.commit }
@@ -12,7 +13,11 @@ describe CommitEntity do
   subject { entity.as_json }
 
   before do
+    render = double('render')
+    allow(render).to receive(:call).and_return(SIGNATURE_HTML)
+
     allow(request).to receive(:project).and_return(project)
+    allow(request).to receive(:render).and_return(render)
   end
 
   context 'when commit author is a user' do
@@ -70,6 +75,15 @@ describe CommitEntity do
       expect(subject.fetch(:description_html)).not_to be_nil
       expect(subject.fetch(:title_html)).not_to be_nil
     end
+
+    context 'when commit has signature' do
+      let(:commit) { project.commit(TestEnv::BRANCH_SHA['signed-commits']) }
+
+      it 'exposes "signature_html"' do
+        expect(request.render).to receive(:call)
+        expect(subject.fetch(:signature_html)).to be SIGNATURE_HTML
+      end
+    end
   end
 
   context 'when commit_url_params is set' do