test module

Author: beakerandjake

src/solutions/importUserSolutionModule.js

@@ -1,4 +1,3 @@
-/* istanbul ignore file */
 import { pathToFileURL } from 'node:url';
 import {
   UserSolutionFileNotFoundError,

tests/solutions/importUserSolutionModule.test.js

@@ -0,0 +1,93 @@
+import { describe, jest, test, afterEach } from '@jest/globals';
+
+// setup mocks
+jest.unstable_mockModule('node:url', () => ({
+  pathToFileURL: (path) => ({ href: path }),
+}));
+class UserSolutionSyntaxErrorMock extends Error {
+  constructor() {
+    super();
+    this.name = 'UserSolutionSyntaxErrorMock';
+  }
+}
+class UserSolutionFileNotFoundErrorMock extends Error {
+  constructor() {
+    super();
+    this.name = 'UserSolutionFileNotFoundErrorMock';
+  }
+}
+jest.unstable_mockModule('src/errors/solutionWorkerErrors.js', () => ({
+  UserSolutionFileNotFoundError: UserSolutionFileNotFoundErrorMock,
+  UserSolutionSyntaxError: UserSolutionSyntaxErrorMock,
+}));
+// import after mocks set up.
+
+describe('importUserSolutionModule', () => {
+  afterEach(() => {
+    jest.clearAllMocks();
+    jest.resetModules();
+  });
+
+  test('returns module', async () => {
+    // mock an module we know exists
+    const modulePath = 'src/main.js';
+    const module = { levelOne: () => {} };
+    jest.unstable_mockModule(modulePath, () => module);
+
+    const { importUserSolutionModule } = await import(
+      '../../src/solutions/importUserSolutionModule.js'
+    );
+    const result = await importUserSolutionModule(modulePath);
+    expect(result).toMatchObject(module);
+  });
+
+  test('throws UserSolutionFileNotFoundError if file not found', async () => {
+    // mock an module we know exists
+    const modulePath = 'src/main.js';
+    const error = new Error();
+    error.code = 'ERR_MODULE_NOT_FOUND';
+    jest.unstable_mockModule(modulePath, () => {
+      throw error;
+    });
+
+    const { importUserSolutionModule } = await import(
+      '../../src/solutions/importUserSolutionModule.js'
+    );
+
+    await expect(async () => importUserSolutionModule(modulePath)).rejects.toThrow(
+      UserSolutionFileNotFoundErrorMock
+    );
+  });
+
+  test('throws UserSolutionSyntaxError if file has syntax error', async () => {
+    // mock an module we know exists
+    const modulePath = 'src/main.js';
+    jest.unstable_mockModule(modulePath, () => {
+      throw new SyntaxError();
+    });
+
+    const { importUserSolutionModule } = await import(
+      '../../src/solutions/importUserSolutionModule.js'
+    );
+
+    await expect(async () => importUserSolutionModule(modulePath)).rejects.toThrow(
+      UserSolutionSyntaxErrorMock
+    );
+  });
+
+  test('throws on unknown error', async () => {
+    // mock an module we know exists
+    const modulePath = 'src/main.js';
+    jest.unstable_mockModule(modulePath, () => {
+      throw new RangeError();
+    });
+
+    const { importUserSolutionModule } = await import(
+      '../../src/solutions/importUserSolutionModule.js'
+    );
+
+    await expect(async () => importUserSolutionModule(modulePath)).rejects.toThrow(
+      RangeError
+    );
+  });
+});