import url from 'node:url' import { createTeardown } from 'fs-teardown' import { installLibrary } from '../module-utils' const fsMock = createTeardown({ rootDir: url.fileURLToPath(new URL('node-esm-tests', import.meta.url)), paths: { 'package.json': JSON.stringify({ type: 'module' }), }, }) test.beforeAll(async () => { await fsMock.prepare() await installLibrary(fsMock.resolve('.')) }) test.afterAll(async ({}, { result }) => { if (result?.state === 'fail') { return } await fsMock.cleanup() }) it('runs in a ESM Node.js project', async () => { await fsMock.create({ 'resolve.mjs': ` console.log('msw:', await import.meta.resolve('msw')) console.log('msw/node:', await import.meta.resolve('msw/node')) console.log('msw/native:', await import.meta.resolve('msw/native')) `, 'runtime.mjs': ` import { http } from 'msw' import { setupServer } from 'msw/node' const server = setupServer( http.get('/resource', () => new Response()) ) console.log(typeof server.listen) `, }) const resolveStdio = await fsMock.exec( /** * @note Using the import meta resolve flag * to enable the "import.meta.resolve" API to see * what library imports resolve to in Node.js ESM. */ 'node --experimental-import-meta-resolve ./resolve.mjs', ) expect(resolveStdio.stderr).toBe('') /** * @todo Take these expected export paths from package.json. * That should be the source of truth. */ expect(resolveStdio.stdout).toMatch( /^msw: (.+?)\/node_modules\/msw\/lib\/core\/index\.mjs/m, ) expect(resolveStdio.stdout).toMatch( /^msw\/node: (.+?)\/node_modules\/msw\/lib\/node\/index\.mjs/m, ) expect(resolveStdio.stdout).toMatch( /^msw\/native: (.+?)\/node_modules\/msw\/lib\/native\/index\.mjs/m, ) /** * @todo Also test the "msw/browser" import that throws, * saying that the "./browser" export is not defined. * That's correct, it's explicitly set as "browser: null" for Node.js. */ const runtimeStdio = await fsMock.exec('node ./runtime.mjs') expect(runtimeStdio.stderr).toBe('') expect(runtimeStdio.stdout).toMatch(/function/m) }) it('runs in a CJS Node.js project', async () => { await fsMock.create({ 'resolve.cjs': ` console.log('msw:', require.resolve('msw')) console.log('msw/node:', require.resolve('msw/node')) console.log('msw/native:', require.resolve('msw/native')) `, 'runtime.cjs': ` const { http } = require('msw') const { setupServer } = require('msw/node') const server = setupServer( http.get('/resource', () => new Response()) ) console.log(typeof server.listen) `, }) const resolveStdio = await fsMock.exec('node ./resolve.cjs') expect(resolveStdio.stderr).toBe('') /** * @todo Take these expected export paths from package.json. * That should be the source of truth. */ /** * @note Although the test requires the package in CJS, * the "module-sync" condition allows loading the ESM build. * This is supported in Node.js v20+. */ expect(resolveStdio.stdout).toMatch( /^msw: (.+?)\/node_modules\/msw\/lib\/core\/index\.mjs/m, ) expect(resolveStdio.stdout).toMatch( /^msw\/node: (.+?)\/node_modules\/msw\/lib\/node\/index\.mjs/m, ) // Must load regular CJS build for React Native. expect(resolveStdio.stdout).toMatch( /^msw\/native: (.+?)\/node_modules\/msw\/lib\/native\/index\.js/m, ) const runtimeStdio = await fsMock.exec('node ./runtime.mjs') expect(runtimeStdio.stderr).toBe('') expect(runtimeStdio.stdout).toMatch(/function/m) })