need help building example, esmregister + esmock

[iambumblehead]

When trying to create an example test with swc and esmock, this error occurs around the types definition file,

node --import @swc-node/register/esm-register --test esmock.node-swc.test.ts

> test:current
> node --import @swc-node/register/esm-register --test esmock.node-swc.test.ts

file:///home/bumble/soft/esmock/src/esmock.d.ts:1
type MockMap = { [specifier: string]: any }
     ^^^^^^^

SyntaxError: Unexpected identifier 'MockMap'
    at ModuleLoader.moduleStrategy (node:internal/modules/esm/translators:169:18)
    at callTranslator (node:internal/modules/esm/loader:272:14)
    at ModuleLoader.moduleProvider (node:internal/modules/esm/loader:278:30)

Thanks in advance for any advice

[Brooooooklyn]

Fixed in #798

[iambumblehead]

The specific error described at the top of this issue is resolved, however, after updating @swc-node/register a new issue is encountered,

✖ should mock js when using swc (34.125566ms)
  file:///home/bumble/soft/esmock/tests/local/mainUtil.js:2
  import babelGeneratedDoubleDefault from 'babelGeneratedDoubleDefault';
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  SyntaxError: The requested module 'babelGeneratedDoubleDefault' does not provide an export named 'default'

The error needs context to be understood but, essentially, @swc-node/register encounters an error loading mixed esm/cjs modules.

Slightly difficult to describe the sequence resulting in the error, here is what happens,

1. 'esmock.node-swc.test.ts' imports '../local/main.js' (esm) link
2. '../local/main.js' imports './mainUtil.js' (esm) link
3. 'mainUtil.js' imports 'babelGeneratedDoubleDefault' (cjs) error link
4. '../package.json' links 'babelGeneratedDoubleDefault' to the local directory package 'babelGeneratedDoubleDefault', link package.json
5. 'babelGeneratedDoubleDefault' describes a cjs module, link babelGeneratedDoubleDefault/package.json, link babelGeneratedDoubleDefault.js

The other loaders used in the test suite process the same import tree without error https://github.com/iambumblehead/esmock/tree/attempt-enable-swc-tests/tests

Thank you for reading me

[Brooooooklyn]

I've tried tsx, it's also throw a error:

// index.ts
import assert from 'node:assert'
import test from 'node:test'

import babelGeneratedDoubleDefault from './babel-generated-double-default'

await test('import default from babel-generated cjs file', () => {
  assert.equal(babelGeneratedDoubleDefault(), 'default.default')
})

pnpm tsx index.ts:

[iambumblehead]

git clone https://github.com/iambumblehead/esm-import-cjs-repro.git
cd esm-import-cjs-repro
npm install
npm run test:node # pass
npm run test:tsx # pass
npm run test:swc # fail

[Brooooooklyn]

https://github.com/iambumblehead/esm-import-cjs-repro.git

@iambumblehead this failed because of the peerDependencies are missing, you need to install @swc/core and typescript, and everything should be fine.

[iambumblehead]

after adding @swc/core and typescript dependencies, tests still fail. Do they need to be declared in a specific way in pacakge.json?

$ cat package.json | grep dependencies -A 6
  "dependencies": {
    "babelGeneratedDoubleDefault": "file:./babelGeneratedDoubleDefault",
    "typescript": "^5.5.3",
    "@swc-node/register": "1.10.2",
    "@swc/core": "^1.6.13",
    "tsx": "^4.15.5"
  },


$ npm install

added 2 packages, and audited 28 packages in 34s

6 packages are looking for funding
  run `npm fund` for details

found 0 vulnerabilities


$ npm run test:swc

> esm-import-cjs-repro@0.0.1 test:swc
> node --import @swc-node/register/esm-register --test test.swc.test.ts

✖ should import babelGeneratedDoubleDefault, cjs deep (12.353619ms)
  file:///home/bumble/soft/esm-import-cjs-repro/src/esmmain2.js:1
  import babelGeneratedDoubleDefault from 'babelGeneratedDoubleDefault';

[iambumblehead]

the first test, importing mixed esm cjs tree passes, but the second test encounters a runtime error,

test('should mock ts when using swc', async () => {
  const main = await esmock('../local/main-ts.ts', {
    path: {
      basename: () => 'hellow'
    }
  })

  assert.strictEqual(main.pathbasenamewrap(), 'hellow')
})

The error occurs when the typescript file "main-ts.ts" is loaded.

test at esmock.node-swc.test.ts:15:1
✖ should mock ts when using swc (5.206873ms)
  SyntaxError [Error]: Unexpected token ':'

main-ts.ts, link

import path from 'path'
import pg from 'pg'

export default {
  pathbasenamewrap: (n: any) => path.basename(n),
  pgpoolwrap: (n: any) => pg.Pool(n)
}

If the typescript : any is removed from the file, the test passes. It seems the file is not transformed.

[iambumblehead]

the error happens when esmock is engaged to load the ts file await esmock('../local/main-ts.ts') using import does not result in an error await import ('../local/main-ts.ts')

the same test using esmock passes when using node-ts, tsx or tsm

[iambumblehead]

At esm-import-cjs-repro, the test is added for tsx and swc and the error is reproduced using swc

git clone https://github.com/iambumblehead/esm-import-cjs-repro.git
cd esm-import-cjs-repro
npm install
npm run test:node # pass
npm run test:tsx # pass
npm run test:swc # fail

[iambumblehead]

related #710

[iambumblehead]

all tests pass :)