Add fixtures used in mock_server

These are the ones needed to support the IDE
starting up.

spec/frontend/fixtures/api_merge_requests.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe API::MergeRequests, '(JavaScript fixtures)', type: :request do
+  include ApiHelpers
+  include JavaScriptFixturesHelpers
+
+  let(:admin) { create(:admin, name: 'root') }
+  let(:namespace) { create(:namespace, name: 'gitlab-test' )}
+  let(:project) { create(:project, :repository, namespace: namespace, path: 'lorem-ipsum') }
+
+  before(:all) do
+    clean_frontend_fixtures('api/merge_requests')
+  end
+
+  it 'api/merge_requests/get.json' do
+    4.times { |i| create(:merge_request, source_project: project, source_branch: "branch-#{i}") }
+
+    get api("/projects/#{project.id}/merge_requests", admin)
+
+    expect(response).to be_successful
+  end
+end

spec/frontend/fixtures/api_projects.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe API::Projects, '(JavaScript fixtures)', type: :request do
+  include ApiHelpers
+  include JavaScriptFixturesHelpers
+
+  let(:admin) { create(:admin, name: 'root') }
+  let(:namespace) { create(:namespace, name: 'gitlab-test' )}
+  let(:project) { create(:project, :repository, namespace: namespace, path: 'lorem-ipsum') }
+  let(:project_empty) { create(:project_empty_repo, namespace: namespace, path: 'lorem-ipsum-empty') }
+
+  before(:all) do
+    clean_frontend_fixtures('api/projects')
+  end
+
+  it 'api/projects/get.json' do
+    get api("/projects/#{project.id}", admin)
+
+    expect(response).to be_successful
+  end
+
+  it 'api/projects/get_empty.json' do
+    get api("/projects/#{project_empty.id}", admin)
+
+    expect(response).to be_successful
+  end
+
+  it 'api/projects/branches/get.json' do
+    get api("/projects/#{project.id}/repository/branches/#{project.default_branch}", admin)
+
+    expect(response).to be_successful
+  end
+end

spec/frontend/fixtures/projects_json.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe 'Projects JSON endpoints (JavaScript fixtures)', type: :controller do
+  include JavaScriptFixturesHelpers
+
+  let(:admin) { create(:admin, name: 'root') }
+  let(:project) { create(:project, :repository) }
+
+  before(:all) do
+    clean_frontend_fixtures('projects_json/')
+  end
+
+  before do
+    project.add_maintainer(admin)
+    sign_in(admin)
+  end
+
+  describe Projects::FindFileController, '(JavaScript fixtures)', type: :controller do
+    it 'projects_json/files.json' do
+      get :list,
+        params: {
+          namespace_id: project.namespace.to_param,
+          project_id: project,
+          id: project.default_branch
+        },
+        format: 'json'
+
+      expect(response).to be_successful
+    end
+  end
+
+  describe Projects::CommitController, '(JavaScript fixtures)', type: :controller do
+    it 'projects_json/pipelines_empty.json' do
+      get :pipelines,
+        params: {
+          namespace_id: project.namespace.to_param,
+          project_id: project,
+          id: project.commit(project.default_branch).id,
+          format: 'json'
+        }
+
+      expect(response).to be_successful
+    end
+  end
+end