Can I use the NPM parser to parse TypeScript?

[Sleepful]

Hello, I found: https://www.npmjs.com/package/oxc-parser

It works well to parse JS files, but it is giving me errors with TS files. Is this expected? It seems the rust parser (https://github.com/oxc-project/oxc/blob/main/crates/oxc_parser/examples/parser.rs) works fine with TS files, so I was expecting the NPM parser to work well too.

[Boshen]

Try passing in the filename with the correct extension, i.e. test.ts.

[Sleepful]

How so? If I understood correctly, parseAsync param is going to be the string source code. It does not take in a filename, does it?

E.g.

oxc.parseAsync(`import { Button } from "../components/Button.tsx";`)
// works fine
oxc.parseAsync(`import type { Signal } from "@preact/signals";`)
// this one gives error because it is not valid JavaScript

[Sleepful]

The above always return the "javascript" language:

{
  type: "Program",
  start: 0,
  end: 7,
  sourceType: {
    language: "javascript",
    moduleKind: "script",
    variant: "standard",
    alwaysStrict: false
  }

Passing in a filename does not work.

oxc.parseAsync(`test.ts`) // does not actually read the file

[Boshen]

Does the TypeScript definition not work?

export function parseSync(sourceText: string, options?: ParserOptions | undefined | null): ParseResult

I'll update the README example regarding the options.

[Sleepful]

@Boshen oh, you are right. I see what you mean now.

This works fine:

parseSync(`import type { Signal } from "@preact/signals";`, {
  sourceFilename: "some.ts",
})

Now that I remember, I had looked at https://github.com/oxc-project/oxc/blob/main/napi/parser/index.d.ts#L82 before posting this discussion, but I was looking for something like "filetype" that I could tell it "TypeScript". It didn't occur to me that sourceFilename was important! Adding a sample in the README for the NPM package where sourceFilename is used for a TS file would have been enough.