test(theme-common): improve test coverage (#6902)

* test(theme-common): improve test coverage

* revert

packages/docusaurus-migrate/src/__tests__/index.test.ts

@@ -0,0 +1,65 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import {jest} from '@jest/globals';
+import {migrateDocusaurusProject} from '../index';
+import path from 'path';
+import fs from 'fs-extra';
+import {posixPath} from '@docusaurus/utils';
+
+async function testMigration(siteDir: string, newDir: string) {
+  const writeMock = jest.spyOn(fs, 'outputFile').mockImplementation(() => {});
+  const mkdirpMock = jest.spyOn(fs, 'mkdirp').mockImplementation(() => {});
+  const mkdirsMock = jest.spyOn(fs, 'mkdirs').mockImplementation(() => {});
+  const copyMock = jest.spyOn(fs, 'copy').mockImplementation(() => {});
+  await migrateDocusaurusProject(siteDir, newDir, true, true);
+  expect(
+    writeMock.mock.calls.sort((a, b) =>
+      posixPath(a[0] as string).localeCompare(posixPath(b[0] as string)),
+    ),
+  ).toMatchSnapshot('write');
+  expect(
+    mkdirpMock.mock.calls.sort((a, b) =>
+      posixPath(a[0] as string).localeCompare(posixPath(b[0] as string)),
+    ),
+  ).toMatchSnapshot('mkdirp');
+  expect(
+    mkdirsMock.mock.calls.sort((a, b) =>
+      posixPath(a[0] as string).localeCompare(posixPath(b[0] as string)),
+    ),
+  ).toMatchSnapshot('mkdirs');
+  expect(
+    copyMock.mock.calls.sort((a, b) =>
+      posixPath(a[0] as string).localeCompare(posixPath(b[0] as string)),
+    ),
+  ).toMatchSnapshot('copy');
+  writeMock.mockRestore();
+  mkdirpMock.mockRestore();
+  mkdirsMock.mockRestore();
+  copyMock.mockRestore();
+}
+
+describe('migration CLI', () => {
+  const fixtureDir = path.join(__dirname, '__fixtures__');
+  it('migrates simple website', async () => {
+    const siteDir = path.join(fixtureDir, 'simple_website', 'website');
+    const newDir = path.join(fixtureDir, 'migrated_simple_site');
+    await testMigration(siteDir, newDir);
+  });
+
+  it('migrates complex website', async () => {
+    const siteDir = path.join(fixtureDir, 'complex_website', 'website');
+    const newDir = path.join(fixtureDir, 'migrated_complex_site');
+    await testMigration(siteDir, newDir);
+  });
+
+  it('migrates missing versions', async () => {
+    const siteDir = path.join(fixtureDir, 'missing_version_website', 'website');
+    const newDir = path.join(fixtureDir, 'migrated_missing_version_site');
+    await testMigration(siteDir, newDir);
+  });
+});