babel-node should add '.ts', '.tsx' as a default extensions to hook into

[stnor]

Bug Report

Current Behavior

I'm running jasmine tests in babel-node in my front-end typescript project, and I got

SyntaxError: Cannot use import statement outside a module

It took me four hours to understand that *.ts files aren't included by default in babel-node. Google/SE was no help.

As Typescript is supported by babel since a while back, it seems resonable that babel-node should hook into '.ts'-files by default? Perhaps '.tsx' too.

See https://babeljs.io/docs/en/next/babel-node.html

Input Code
DOESN'T WORK
package.json:

  "scripts": {
    "test": "npx babel-node spec/run.ts",
  },

DOES WORK
package.json:

  "scripts": {
    "test": "npx babel-node -x '.ts' spec/run.ts",
  },

[babel-bot]

Hey @stnor! We really appreciate you taking the time to report an issue. The collaborators on this project attempt to help as many people as possible, but we're a limited number of volunteers, so it's possible this won't be addressed swiftly.

If you need any help, or just have general Babel or JavaScript questions, we have a vibrant Slack community that typically always has someone willing to help. You can sign-up here for an invite."

[dilyanpalauzov]

Do you mean what is described at microsoft/TypeScript#38546?

In particular that import ./b in typescript means all of import ./b.ts, import ./b.js or import the directory ./b/ as package, whichever exists, while in ES6 syntax, one has to be explicit import ./b.js, import ./b.ts or import ./b. Sadly, I had no luck in communicating the problem to the TypeScript team and the documentation, how alternative typescript parsers should behave, is vague.

Moreover, typescript does accept as input syntax import ./b.js when it means b.ts, but preset-typescript on that input says b.js does not exist (because b.ts exists). preset-babel would accept as input import ./b.ts, but this is not accepted by typescript. On input import ./b typescript with target es2020 generates output import ./b, but this is not valid ES6 when the author wants to import the generated ./b.ts -> ./b.js. So there is no input that works accross all combinations.

The problem is, that one cannot use the same input for preset-typescript and typescript, when the target of the latter is es2020, and to get the result of both parsers working at the same time.

[dilyanpalauzov]

I edited the comment above several times.

[nicolo-ribaudo]

Related - #8652

[stnor]

@dilyanpalauzov no. It's what @nicolo-ribaudo ref'ed..