ESM mode does not properly infer config `target` from `"module": "node*"`

nickserv commented 2 years ago

Search Terms

ESM target
Top-level 'for await' loops are only allowed when the 'module' option is set to 'es2022', 'esnext', 'system', 'node16', or 'nodenext', and the 'target' option is set to 'es2017' or higher.

Expected Behavior

Using "module": "node16" or "module": "nodenext" sets target to es2017 or newer and compiles without an error. This is what happens if you use tsc instead of ts-node --esm.

Actual Behavior

target is set to the default of es5, causing the following error:

/usr/local/lib/node_modules/ts-node/src/index.ts:859
    return new TSError(diagnosticText, diagnosticCodes, diagnostics);
           ^
TSError: ⨯ Unable to compile TypeScript:
index.ts:8:5 - error TS1432: Top-level 'for await' loops are only allowed when the 'module' option is set to 'es2022', 'esnext', 'system', 'node16', or 'nodenext', and the 'target' option is set to 'es2017' or higher.

8 for await (const name of getBeatles()) console.log(name)
      ~~~~~

    at createTSError (/usr/local/lib/node_modules/ts-node/src/index.ts:859:12)
    at reportTSError (/usr/local/lib/node_modules/ts-node/src/index.ts:863:19)
    at getOutput (/usr/local/lib/node_modules/ts-node/src/index.ts:1077:36)
    at Object.compile (/usr/local/lib/node_modules/ts-node/src/index.ts:1433:41)
    at transformSource (/usr/local/lib/node_modules/ts-node/src/esm.ts:400:37)
    at /usr/local/lib/node_modules/ts-node/src/esm.ts:278:53
    at async addShortCircuitFlag (/usr/local/lib/node_modules/ts-node/src/esm.ts:409:15)
    at async nextLoad (node:internal/modules/esm/loader:163:22)
    at async ESMLoader.load (node:internal/modules/esm/loader:601:20)
    at async ESMLoader.moduleProvider (node:internal/modules/esm/loader:457:11) {
  diagnosticCodes: [ 1432 ]
}

Steps to reproduce the problem

Use "module": "node16" or "module": "nodenext" without target and with "type": "module" in package.json.

Minimal reproduction

// index.ts
async function* getBeatles() {
  yield "John"
  yield "Paul"
  yield "George"
  yield "Ringo"
}

for await (const name of getBeatles()) console.log(name)

ts-node --esm index.ts

Specifications

ts-node version: 10.9.1
node version: 18.10.0
TypeScript version: 4.8.4

tsconfig.json, if you're using one:

{
"compilerOptions": {
"module": "node16",
"moduleDetection": "force"
}
}

package.json:
```
{
"private": true,
"type": "module"
}
```
Operating system and version: macOS 12.6 (Monterey)

cspotcode commented 2 years ago

I'm guessing this is the culprit.

https://github.com/TypeStrong/ts-node/blob/8b09d49b26c1c25e34133b857c073729dd691f11/src/configuration.ts#L45-L48

Probably this logic made more sense in the past, but things have changed since then.

cspotcode commented 2 years ago

While we're at it we can look at this, too.

https://github.com/TypeStrong/ts-node/blob/8b09d49b26c1c25e34133b857c073729dd691f11/src/configuration.ts#L50

I don't remember off-hand but I think there are situations where you need to specify module and moduleResolution, when one should be sufficient to imply the other.

TypeStrong / ts-node