TypeError: RegExpPrototypeExec is not a function when using esm loader

[SimonSiefke]

Search Terms

RegExpPrototypeExec, ESM

Expected Behavior

It shows no error

Actual Behavior

It shows an error:

(node:9814) ExperimentalWarning: --experimental-loader is an experimental feature. This feature could change at any time
(Use `node --trace-warnings ...` to show where the warning was created)
TypeError: RegExpPrototypeExec is not a function
    at defaultGetFormat (/tmp/tsnode-bug/node_modules/ts-node/dist-raw/node-esm-default-get-format.js:50:24)
    at defer (/tmp/tsnode-bug/node_modules/ts-node/src/esm.ts:170:7)
    at /tmp/tsnode-bug/node_modules/ts-node/src/esm.ts:175:14
    at Generator.next (<anonymous>)
    at /tmp/tsnode-bug/node_modules/ts-node/dist/esm.js:8:71
    at new Promise (<anonymous>)
    at __awaiter (/tmp/tsnode-bug/node_modules/ts-node/dist/esm.js:4:12)
    at getFormat (/tmp/tsnode-bug/node_modules/ts-node/dist/esm.js:108:16)
    at /tmp/tsnode-bug/node_modules/ts-node/src/esm.ts:127:14
    at Generator.next (<anonymous>)

Steps to reproduce the problem

const supportsESM = async () => {
  try {
    // @ts-ignore
    await import("data:text/javascript,");
    return true;
  } catch (error) {
    console.error(error);
  }
  return false;
};

supportsESM();

Using node --loader ts-node/esm src/index.ts results in the error above

Minimal reproduction

See https://github.com/SimonSiefke/ts-node-esm-bug

Specifications

ts-node v10.3.1
node v17.0.1
compiler v4.5.0-beta

• ts-node version:
• node version:
• TypeScript version:
• tsconfig.json, if you're using one:

{
  "compilerOptions": {
    "outDir": "dist",
    "target": "ESNext",
    "module": "ESNext",
    "lib": ["ESNext"]
  },
  "include": ["src"]
}

• Operating system and version:
  Ubuntu 21.04

[cspotcode]

Thanks for the detailed reproduction. This looks like a missing primordial in this file: https://github.com/TypeStrong/ts-node/blob/main/dist-raw/node-primordials.js

It is only used for data: URIs which is probably why our tests didn't catch it.

ts-node/dist-raw/node-esm-default-get-format.js

Lines 49 to 50 in 8cde25b

	if (parsed.protocol === 'data:') {
	const [ , mime ] = RegExpPrototypeExec(

Thankfully, should be a quick fix, and we can add a data URI test while we're at it.

[cspotcode]

@SimonSiefke this has been published in 10.4.0; please let us know if it fixes the problem for you.

https://github.com/TypeStrong/ts-node/releases/tag/v10.4.0

[SimonSiefke]

Works great. Thank you!