Added e2e tests and snapshot files

e2e/spec/classDiagram.spec.js

@@ -0,0 +1,27 @@
+/* eslint-env jest */
+import { imgSnapshotTest } from '../helpers/util.js'
+const { toMatchImageSnapshot } = require('jest-image-snapshot')
+
+expect.extend({ toMatchImageSnapshot })
+
+describe('Sequencediagram', () => {
+  it('should render a simple class diagrams', async () => {
+    await imgSnapshotTest(page, `
+    classDiagram
+      Class01 <|-- AveryLongClass : Cool
+      Class03 *-- Class04
+      Class05 o-- Class06
+      Class07 .. Class08
+      Class09 --> C2 : Where am i?
+      Class09 --* C3
+      Class09 --|> Class07
+      Class07 : equals()
+      Class07 : Object[] elementData
+      Class01 : size()
+      Class01 : int chimp
+      Class01 : int gorilla
+      Class08 <--> C2: Cool label
+      `,
+    {})
+  })
+})