Issue migrating my generators' tests to TypeScript (ERR_PACKAGE_PATH_NOT_EXPORTED)

[groovytron]

Hi,

I'm having troubles migrating my generators' tests to TypeScript.

My project is https://github.com/groovytron/generator-skjol. The migration branch is migrate-to-typescript.

I get the following error when I run npm run test (which runs the tests with Mocha like the previous version of my project):

> [email protected] test
> nyc --all --reporter lcov mocha


Error [ERR_PACKAGE_PATH_NOT_EXPORTED]: No "exports" main defined in /home/julien/Documents/swissted/generator-skjol/node_modules/yeoman-test/package.json
    at new NodeError (node:internal/errors:399:5)
    at exportsNotFound (node:internal/modules/esm/resolve:266:10)
    at packageExportsResolve (node:internal/modules/esm/resolve:546:13)
    at resolveExports (node:internal/modules/cjs/loader:551:36)
    at Function.Module._findPath (node:internal/modules/cjs/loader:620:31)
    at Function.Module._resolveFilename (node:internal/modules/cjs/loader:1039:27)
    at Function.Module._resolveFilename.sharedData.moduleResolveFilenameHook.installedValue [as _resolveFilename] (/home/julien/Documents/swissted/generator-skjol/node_modules/@cspotcode/source-map-support/source-map-support.js:811:30)
    at Function.Module._load (node:internal/modules/cjs/loader:898:27)
    at Module.require (node:internal/modules/cjs/loader:1120:19)
    at require (node:internal/modules/helpers:112:18)
    at Object.<anonymous> (/home/julien/Documents/swissted/generator-skjol/test/slides.spec.ts:2:15)
    at Module._compile (node:internal/modules/cjs/loader:1239:14)
    at Module.replacementCompile (/home/julien/Documents/swissted/generator-skjol/node_modules/append-transform/index.js:60:13)
    at Module.m._compile (/home/julien/Documents/swissted/generator-skjol/node_modules/ts-node/src/index.ts:1618:23)
    at module.exports (/home/julien/Documents/swissted/generator-skjol/node_modules/default-require-extensions/js.js:7:9)
    at /home/julien/Documents/swissted/generator-skjol/node_modules/append-transform/index.js:64:4
    at require.extensions.<computed> (/home/julien/Documents/swissted/generator-skjol/node_modules/ts-node/src/index.ts:1621:12)
    at Object.<anonymous> (/home/julien/Documents/swissted/generator-skjol/node_modules/append-transform/index.js:64:4)
    at Module.load (node:internal/modules/cjs/loader:1096:32)
    at Function.Module._load (node:internal/modules/cjs/loader:935:12)
    at Module.require (node:internal/modules/cjs/loader:1120:19)
    at require (node:internal/modules/helpers:112:18)
    at Object.exports.requireOrImport (/home/julien/Documents/swissted/generator-skjol/node_modules/mocha/lib/nodejs/esm-utils.js:53:16)
    at async Object.exports.loadFilesAsync (/home/julien/Documents/swissted/generator-skjol/node_modules/mocha/lib/nodejs/esm-utils.js:100:20)
    at async singleRun (/home/julien/Documents/swissted/generator-skjol/node_modules/mocha/lib/cli/run-helpers.js:125:3)
    at async Object.exports.handler (/home/julien/Documents/swissted/generator-skjol/node_modules/mocha/lib/cli/run.js:370:5)

My current node version is v19.4.0.

Is there an issue with yeoman-test's exports or am I doing something wrong with my Mocha TypeScript configuration ?

I tried to use Jest instead because I was suspecting there was an issue with ts-node when used with Mocha but I stumble on the same error. Jest is installed to. You can test with Jest by renaming the slides.spec.jest.ts into slides.spec.ts and run npm run jest.

I'm actually just testing the slides generator so only the script slides.spec.ts is executed at the moment. I will migrate the other tests once this one works.

Thanks a lot for your help and have a nice day.

[Tateuf]

same error for me, i try to use yeoman-test for my generator with mocha and exactly the same error : ( Always no solution ?

[mshima]

yeoman-test@7 is in typescript and have built-in types, maybe drop the @types/yeoman-test dependency?

[groovytron]

yeoman-test@7 is in typescript and have built-in types, maybe drop the @types/yeoman-test dependency?

Thanks for your answer but removing @types/yeoman-test doesn't fix the issue. I still get the same error.

[groovytron]

I also tried to upgrade to [email protected] but the error still persists.

[mshima]

yeoman-test@7 is native esm: https://github.com/yeoman/yeoman-test/releases/tag/v7.0.0

You need to convert your project to esm, commonjs won't work:
https://github.com/groovytron/generator-skjol/blob/690b27f8392c1fdd03c8fb03813f83b1bbafdaf3/package.json#L8

Or stick with yeoman-test@6

[groovytron]

@mshima thanks a lot for your help. My tests are now passing. I lost my code coverage but I'll dig into it. I'm not sure the problem comes from yeoman-test.

In case anybody encounters this issue, here is a diff between before and after the TypeScript migration: groovytron/generator-skjol@1.1.1...2.0.0-rc.0

[groovytron]

I managed to fix my code coverage issue by migrating to c8. It looks like nyc cannot generate coverage with ESM at the moment.

Here are my changes: groovytron/generator-skjol@be4970f

Here are my findings:

• Nyc on ESM Node.js 13 (no babel) istanbuljs/nyc#1287 (comment)
• https://stackoverflow.com/questions/74711290/how-to-use-esm-and-typescript-in-node-js-with-test-coverage

[mshima]

For future reference, the project don't need to be esm, tests need to be esm. Can use mts extension.

[ssoworld]

We should consider backward-compatibility and not have to force users to move to ECMA. Companies using this have to seriously consider the consequences of not unit testing their generators and having to rely on older versions while maintaining their generators. Sure, reverting to 6 is OK, but when one runs npm outdated or has Renovate (or equivalent) automating their updates, they have to take steps to disable this. Let's make it simple.

[mshima]

Dependencies would be outdated since they are migrating to esm too.
A dev dependency like yeoman-test is much easier to workaround:

describe(() => {
  let helpers;
  before(async() => {
    helpers = (await import('yeoman-test')).default;
  });
});