Add routing specs for environment folders

spec/routing/environments_spec.rb

+require 'spec_helper'
+
+describe Projects::EnvironmentsController, :routing do
+  let(:project) { create(:empty_project) }
+
+  let(:environment) do
+    create(:environment, project: project,
+                         name: 'staging-1.0/review')
+  end
+
+  let(:environments_route) do
+    "#{project.namespace.name}/#{project.name}/environments/"
+  end
+
+  describe 'routing environment folders' do
+    context 'when using JSON format' do
+      it 'correctly matches environment name and JSON format' do
+        expect(get_folder('staging-1.0.json'))
+          .to route_to(*folder_action(id: 'staging-1.0', format: 'json'))
+      end
+    end
+
+    context 'when using HTML format' do
+      it 'correctly matches environment name and HTML format' do
+        expect(get_folder('staging-1.0.html'))
+          .to route_to(*folder_action(id: 'staging-1.0', format: 'html'))
+      end
+    end
+
+    context 'when using implicit format' do
+      it 'correctly matches environment name' do
+        expect(get_folder('staging-1.0'))
+          .to route_to(*folder_action(id: 'staging-1.0'))
+      end
+    end
+  end
+
+  def get_folder(folder)
+    get("#{project.namespace.name}/#{project.name}/" \
+        "environments/folders/#{folder}")
+  end
+
+  def folder_action(**opts)
+    options = { namespace_id: project.namespace.name,
+                project_id: project.name }
+
+    ['projects/environments#folder', options.merge(opts)]
+  end
+end