Unknown file extension ".ts" with "type": "module"

[andreidmt]

node -r swc-register src/**/*.test.ts works as expected if "type": "module" is not present in package.json, otherwise the script fails with:

> node -r swc-register src/**/*.test.ts

internal/process/esm_loader.js:74
    internalBinding('errors').triggerUncaughtException(
                              ^

TypeError [ERR_UNKNOWN_FILE_EXTENSION]: Unknown file extension ".ts" for /src/sum/sum.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 Loader.import (internal/modules/esm/loader.js:176:17)
    at Object.loadESM (internal/process/esm_loader.js:68:5) {
  code: 'ERR_UNKNOWN_FILE_EXTENSION'
}

Adding --experimental-specifier-resolution=node fixes it but the fails with:

> node --experimental-specifier-resolution=node -r swc-register src/**/*.test.ts

internal/process/esm_loader.js:74
    internalBinding('errors').triggerUncaughtException(
                              ^

TypeError [ERR_INVALID_MODULE_SPECIFIER]: Invalid module "file:///src/sum/sum.test.ts"
    at Loader.getFormat (internal/modules/esm/loader.js:117:13)
    at Loader.getModuleJob (internal/modules/esm/loader.js:242:20)
    at Loader.import (internal/modules/esm/loader.js:176:17)
    at Object.loadESM (internal/process/esm_loader.js:68:5) {
  code: 'ERR_INVALID_MODULE_SPECIFIER'
}

Using node v14.17.0, .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
    }
  }
}

[Songkeys]

Thanks for reporting. An esm loader is needed to be implemented. I'll fix this later.

[Songkeys]

After taking another look, I'm not quite sure about how this should be implemented.

ts-node has given a good example https://github.com/TypeStrong/ts-node/blob/3a2848c9968f03f7b05e57e833ca256b52ab4e18/src/esm.ts but it involves many experimental features and immature specs. TypeStrong/ts-node#1007

We should expect TypeScript supporting ESM first then consider what we should follow. This should be covered in TypeScript 4.6 (ideally). microsoft/TypeScript#46452

If anyone has a better solution please let me know :)