Unknown file extension ".ts"

[andreidmt]

Trying to run node -r @swc/register test.ts throws the following:

❯ node -r @swc/register test.ts
internal/process/esm_loader.js:74
    internalBinding('errors').triggerUncaughtException(
                              ^
                              
TypeError [ERR_UNKNOWN_FILE_EXTENSION]: Unknown file extension ".ts" for test.ts
    at Loader.defaultGetFormat [as _getFormat] (internal/modules/esm/get_format.js:71:15)
    at Loader.getFormat (internal/modules/esm/loader.js:104:42)
    at Loader.getModuleJob (internal/modules/esm/loader.js:242:31)
    at async Loader.import (internal/modules/esm/loader.js:176:17)
    at async Object.loadESM (internal/process/esm_loader.js:68:5) {
  code: 'ERR_UNKNOWN_FILE_EXTENSION'
}

Context

• node, npm: v14.17, v8
• package.json:

...
  "type": "module",
...
    "@swc/cli": "^0.1.51",
    "@swc/core": "^1.2.111",
    "@swc/register": "^0.1.7",

• .swcrc

{
  "minify": false,
  "sourceMaps": true,
  "env": {
    "target": "node",
    "mode": "entry",
    "coreJs": 3
  },
  "module": {
    "type": "es6"
  },
  "jsc": {
    "parser": {
      "syntax": "typescript",
      "tsx": false,
      "decorators": false,
      "dynamicImport": false
    }
  }
}

[vtereshyn]

any updates here? :)

[jwalton]

Removing "type": "module" from your package.json will fix this. I doubt this will be fixed any time soon, because as @babel/register notes:

Note: @babel/register does not support compiling native Node.js ES modules on the fly, since currently there is no stable API for intercepting ES modules loading.

[vtereshyn]

Removing "type": "module" from your package.json will fix this. I doubt this will be fixed any time soon, because as @babel/register notes:

Note: @babel/register does not support compiling native Node.js ES modules on the fly, since currently there is no stable API for intercepting ES modules loading.

this is not a fix, if you're using ESM instead of CJS. ESM requires to have "type": "module" in your package.json

[jwalton]

this is not a fix

It is sadly not. But until node provides an API to intercept loading modules (which I suspect is unlikely soon, if ever) there's no way to fix this.

[rabinage]

There is some progress here

Until it's merged you can compile SWC on the fly using ts-node

node node_modules/ts-node/dist/bin.js --experimental-specifier-resolution=node --esm --swc ./index.ts

SWC+ESM project example

[matthew-dean]

Removing "type": "module" from your package.json will fix this

It won't, actually. Because now there are lots of packages in the NPM ecosystem that use this, which this will also fail to load.