fix tests

packages/docusaurus-bundler/src/loaders/__tests__/jsLoader.test.ts

@@ -0,0 +1,77 @@
+/**
+ * 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 {fromPartial} from '@total-typescript/shoehorn';
+import {createJsLoaderFactory} from '../jsLoader';
+
+import type {RuleSetRule} from 'webpack';
+
+describe('createJsLoaderFactory', () => {
+  function testJsLoaderFactory(
+    siteConfig?: Parameters<typeof createJsLoaderFactory>[0]['siteConfig'],
+  ) {
+    return createJsLoaderFactory({
+      siteConfig: {
+        ...siteConfig,
+        webpack: {
+          jsLoader: 'babel',
+          ...siteConfig?.webpack,
+        },
+        future: fromPartial(siteConfig?.future),
+      },
+    });
+  }
+
+  it('createJsLoaderFactory defaults to babel loader', async () => {
+    const createJsLoader = await testJsLoaderFactory();
+    expect(createJsLoader({isServer: true}).loader).toBe(
+      require.resolve('babel-loader'),
+    );
+    expect(createJsLoader({isServer: false}).loader).toBe(
+      require.resolve('babel-loader'),
+    );
+  });
+
+  it('createJsLoaderFactory accepts loaders with preset', async () => {
+    const createJsLoader = await testJsLoaderFactory({
+      webpack: {jsLoader: 'babel'},
+    });
+
+    expect(
+      createJsLoader({
+        isServer: true,
+      }).loader,
+    ).toBe(require.resolve('babel-loader'));
+    expect(
+      createJsLoader({
+        isServer: false,
+      }).loader,
+    ).toBe(require.resolve('babel-loader'));
+  });
+
+  it('createJsLoaderFactory allows customization', async () => {
+    const customJSLoader = (isServer: boolean): RuleSetRule => ({
+      loader: 'my-fast-js-loader',
+      options: String(isServer),
+    });
+
+    const createJsLoader = await testJsLoaderFactory({
+      webpack: {jsLoader: customJSLoader},
+    });
+
+    expect(
+      createJsLoader({
+        isServer: true,
+      }),
+    ).toEqual(customJSLoader(true));
+    expect(
+      createJsLoader({
+        isServer: false,
+      }),
+    ).toEqual(customJSLoader(false));
+  });
+});