fix: Move content into to frontend directory

Doing this BEFORE the merge prevents a lot of merge conflicts.

Signed-off-by: Tilman Vatteroth <git@tilmanvatteroth.de>

frontend/src/extensions/extra-integrations/abcjs/abcjs-markdown-extension.test.tsx

@@ -0,0 +1,46 @@
+/*
+ * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import React from 'react'
+import { render } from '@testing-library/react'
+import * as AbcFrameModule from './abc-frame'
+import { AbcjsMarkdownExtension } from './abcjs-markdown-extension'
+import { mockI18n } from '../../../components/markdown-renderer/test-utils/mock-i18n'
+import type { CodeProps } from '../../../components/markdown-renderer/replace-components/code-block-component-replacer'
+import { TestMarkdownRenderer } from '../../../components/markdown-renderer/test-utils/test-markdown-renderer'
+
+jest.mock('./abc-frame')
+
+describe('AbcJs Markdown Extension', () => {
+  beforeAll(async () => {
+    jest.spyOn(AbcFrameModule, 'AbcFrame').mockImplementation((({ code }) => {
+      return (
+        <span>
+          this is a mock for abc js frame
+          <code>{code}</code>
+        </span>
+      )
+    }) as React.FC<CodeProps>)
+    await mockI18n()
+  })
+
+  afterAll(() => {
+    jest.resetModules()
+    jest.restoreAllMocks()
+  })
+
+  it('renders an abc codeblock', () => {
+    const view = render(
+      <TestMarkdownRenderer
+        extensions={[new AbcjsMarkdownExtension()]}
+        content={
+          '```abc\nX:1\\nT:Speed the Plough\\nM:4/4\\nC:Trad.\\nK:G\\n|:GABc dedB|dedB dedB|c2ec B2dB|c2A2 A2BA|\\nGABc dedB|dedB dedB|c2ec B2dB|A2F2 G4:|\\n|:g2gf gdBd|g2f2 e2d2|c2ec B2dB|c2A2 A2df|\\ng2gf g2Bd|g2f2 e2d2|c2ec B2dB|A2F2 G4:|\n```'
+        }
+      />
+    )
+    expect(view.container).toMatchSnapshot()
+  })
+})