Annabel Gray
--- a/app/controllers/projects/merge_requests_controller.rb
+++ b/app/controllers/projects/merge_requests_controller.rb
    end
  end

+  def pipelines
+    @pipelines = Ci::Pipeline.where(ref: @merge_request.source_branch)
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
    diverged_commits_count > 0
  end

+  def commits_sha
+    commits.map(&:sha)
+  end
+
  def pipeline
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
    diverged_commits_count > 0
  end

+  def commits_sha
+    commits.map(&:sha)
+  end
+
--- a/app/views/projects/merge_requests/_show.html.haml
+++ b/app/views/projects/merge_requests/_show.html.haml
            Commits
            %span.badge= @commits_count
        - if @pipeline
+          %li.pipelines-tab
+            = link_to pipelines_namespace_project_merge_request_path(@project.namespace, @project, @merge_request), data: {target: '#pipelines', action: 'pipelines', toggle: 'tab'} do
--- a/spec/features/merge_requests/pipelines_spec.rb 0 → 100644
+++ b/spec/features/merge_requests/pipelines_spec.rb 0 → 100644
+    login_as user
+  end
+
+  context 'with pipelines' do
+    let!(:pipeline) do
+      create(:ci_empty_pipeline,
+             project: merge_request.source_project,
+             ref: merge_request.source_branch,
+             sha: merge_request.diff_head_sha)
+    end
+
+    before do
+      visit namespace_project_merge_request_path(project.namespace, project, merge_request)
+    end
+
+    scenario 'does click a pipeline tab and sees a list of pipelines' do
--- a/spec/features/merge_requests/pipelines_spec.rb 0 → 100644
+++ b/spec/features/merge_requests/pipelines_spec.rb 0 → 100644
+  context 'with pipelines' do
+    let!(:pipeline) do
+      create(:ci_empty_pipeline,
+             project: merge_request.source_project,
+             ref: merge_request.source_branch,
+             sha: merge_request.diff_head_sha)
+    end
+
+    before do
+      visit namespace_project_merge_request_path(project.namespace, project, merge_request)
+    end
+
+    scenario 'does click a pipeline tab and sees a list of pipelines' do
+      page.within('.merge-request-tabs') do
+        click_link('Pipelines')
+      end
--- a/spec/features/merge_requests/pipelines_spec.rb 0 → 100644
+++ b/spec/features/merge_requests/pipelines_spec.rb 0 → 100644
+    scenario 'does click a pipeline tab and sees a list of pipelines' do
+      page.within('.merge-request-tabs') do
+        click_link('Pipelines')
+      end
+      wait_for_ajax
+
+      expect(page).to have_selector('.pipeline-actions')
+    end
+  end
+
+  context 'without pipelines' do
+    before do
+      visit namespace_project_merge_request_path(project.namespace, project, merge_request)
+    end
+
+    scenario 'does not find a pipeline link' do
--- a/spec/features/merge_requests/pipelines_spec.rb 0 → 100644
+++ b/spec/features/merge_requests/pipelines_spec.rb 0 → 100644
+        click_link('Pipelines')
+      end
+      wait_for_ajax
+
+      expect(page).to have_selector('.pipeline-actions')
+    end
+  end
+
+  context 'without pipelines' do
+    before do
+      visit namespace_project_merge_request_path(project.namespace, project, merge_request)
+    end
+
+    scenario 'does not find a pipeline link' do
+      page.within('.merge-request-tabs') do
+        expect(page).not_to have_link('Pipelines')
--- a/spec/models/merge_request_spec.rb
+++ b/spec/models/merge_request_spec.rb
    subject { create :merge_request, :simple }
  end

+  describe '#commits_sha' do
+    let(:commit0) { double('commit0', sha: 'sha1') }
+    let(:commit1) { double('commit1', sha: 'sha2') }
+    let(:commit2) { double('commit2', sha: 'sha3') }
+
+    before do
+      allow(subject).to receive(:commits).and_return([commit0, commit1, commit2])
+    end
+
+    it 'returns sha of commits' do
+      expect(subject.commits_sha).to contain_exactly('sha1', 'sha2', 'sha3')
+    end
+  end
--- a/spec/models/merge_request_spec.rb
+++ b/spec/models/merge_request_spec.rb
    end
  end

+  describe '#all_pipelines' do
+    let(:commit0) { double('commit0', sha: 'sha1') }
+    let(:commit1) { double('commit1', sha: 'sha2') }
+    let(:commit2) { double('commit2', sha: 'sha3') }
+    let!(:pipeline) { create(:ci_empty_pipeline, project: subject.source_project, sha: 'sha1', ref: subject.source_branch) }
+    let!(:pipeline2) { create(:ci_empty_pipeline, project: subject.source_project, sha: 'sha1', ref: subject.source_branch) }
+    let!(:pipeline3) { create(:ci_empty_pipeline, project: subject.source_project, sha: 'sha2', ref: subject.source_branch) }
+    let!(:pipeline4) { create(:ci_empty_pipeline, project: subject.target_project, sha: 'sha1', ref: subject.target_branch) }
+
+    before do
+      allow(subject).to receive(:commits).and_return([commit0, commit1, commit2])
+    end
--- a/app/assets/javascripts/merge_request_tabs.js
+++ b/app/assets/javascripts/merge_request_tabs.js
      });
    };

+    MergeRequestTabs.prototype.loadPipelines = function(source) {
+      if (this.pipelinesLoaded) {
+        return;
+      }
+      return this._get({
+        url: source + ".json",
+        success: (function(_this) {
+          return function(data) {
+            document.querySelector("div#pipelines").innerHTML = data.html;
--- a/app/assets/javascripts/merge_request_tabs.js
+++ b/app/assets/javascripts/merge_request_tabs.js
      });
    };

+    MergeRequestTabs.prototype.loadPipelines = function(source) {
+      if (this.pipelinesLoaded) {
+        return;
+      }
+      return this._get({
--- a/app/assets/javascripts/merge_request_tabs.js
+++ b/app/assets/javascripts/merge_request_tabs.js
      });
    };

+    MergeRequestTabs.prototype.loadPipelines = function(source) {
+      if (this.pipelinesLoaded) {
+        return;
+      }
+      return this._get({
+        url: source + ".json",
+        success: (function(_this) {