TypeScript installation works with tests/test.ts, not tests/test.js

[jtlapp]

Describe the bug

I answered 'yes' to installing with TypeScript, but yarn test and npm test would bomb with this error:

Error [ERR_REQUIRE_ESM] [ERR_REQUIRE_ESM]: Must use import to load ES Module: /Users/joe/repos/cavesite/tests/test.js

I solved the problem by renaming tests/test.js to tests/test.ts.

The main problem with this is that it sent me for a spin around the Internet trying to figure out how to get things working.

(Aside: I'm still trying to figure out how to run src/**/*.test.ts unit tests, via either playwright or jest.)

Reproduction

1. Install SvelteKit with TypeScript.
2. Run yarn test or npm test.

Logs

Error [ERR_REQUIRE_ESM] [ERR_REQUIRE_ESM]: Must use import to load ES Module: /Users/joe/repos/cavesite/tests/test.js
require() of ES modules is not supported.
require() of /Users/joe/repos/cavesite/tests/test.js from /Users/joe/repos/cavesite/node_modules/@playwright/test/lib/loader.js is an ES module file as it is a .js file whose nearest parent package.json contains "type": "module" which defines all .js files in that package scope as ES modules.
Instead rename test.js to end in .cjs, change the requiring code to use import(), or remove "type": "module" from /Users/joe/repos/cavesite/package.json.


    at new NodeError (internal/errors.js:322:7)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1102:13)
    at Module.load (internal/modules/cjs/loader.js:950:32)
    at Function.Module._load (internal/modules/cjs/loader.js:790:12)
    at Module.require (internal/modules/cjs/loader.js:974:19)
    at require (internal/modules/cjs/helpers.js:93:18)
    at Loader._requireOrImport (/Users/joe/repos/cavesite/node_modules/@playwright/test/lib/loader.js:244:14)
    at Loader.loadTestFile (/Users/joe/repos/cavesite/node_modules/@playwright/test/lib/loader.js:142:18)
    at Runner._runFiles (/Users/joe/repos/cavesite/node_modules/@playwright/test/lib/runner.js:295:44)
    at Runner._run (/Users/joe/repos/cavesite/node_modules/@playwright/test/lib/runner.js:231:12)
    at TimeoutRunner.run (/Users/joe/repos/cavesite/node_modules/playwright-core/lib/utils/async.js:38:14)
    at raceAgainstTimeout (/Users/joe/repos/cavesite/node_modules/playwright-core/lib/utils/async.js:85:15)
    at Runner.runAllTests (/Users/joe/repos/cavesite/node_modules/@playwright/test/lib/runner.js:188:20)
    at runTests (/Users/joe/repos/cavesite/node_modules/@playwright/test/lib/cli.js:184:18)
    at Command.<anonymous> (/Users/joe/repos/cavesite/node_modules/@playwright/test/lib/cli.js:79:7)

System Info

System:
    OS: macOS 10.15.5
    CPU: (4) x64 Intel(R) Core(TM) i3-8100B CPU @ 3.60GHz
    Memory: 747.37 MB / 32.00 GB
    Shell: 5.0.11 - /usr/local/bin/bash
  Binaries:
    Node: 14.18.0 - /usr/local/bin/node
    Yarn: 1.22.10 - /usr/local/bin/yarn
    npm: 8.1.4 - /usr/local/bin/npm
  Browsers:
    Chrome: 99.0.4844.51
    Safari: 13.1.1
  npmPackages:
    @sveltejs/adapter-auto: next => 1.0.0-next.31 
    @sveltejs/kit: ^1.0.0-next.298 => 1.0.0-next.298 
    svelte: ^3.44.0 => 3.46.4

Severity

annoyance

Additional Information

No response