Transformer don't take source_type param

[overlookmotel]

Currently Transformer::new takes a source_type param:

oxc/crates/oxc_transformer/src/lib.rs

Lines 76 to 86 in bc757c8

	pub fn new(
	allocator: &'a Allocator,
	source_path: &Path,
	source_type: SourceType,
	source_text: &'a str,
	trivias: Trivias,
	options: TransformOptions,
	) -> Self {
	let ctx = TransformCtx::new(source_path, source_type, source_text, trivias, &options);
	Self { ctx, options, allocator }
	}

Can we get rid of it? source_type is present in Program and parser updates it from "unambiguous" to either "script" or "module".

It seems to make more sense to use the value of source_type present in Program, than allow user to over-ride it.

I can't see any circumstance in which that's a useful thing to do, and it's a potential footgun. It's confusing that in transformer it's possible that self.ctx.source_type.is_script() != !self.ctx.source_type.is_module(), because it can also be "unambiguous". That's not theoretical - I hit this problem while trying to pass some TypeScript tests.

If for some obscure reason, the user does want to override it, they can always alter the value of Program::source_type before passing Program to transformer.

[Boshen]

Yes.

I also wanted a bigger API change for Source with path, text and related friends. But you may make this smaller breaking API change first.

[overlookmotel]

I also wanted a bigger API change for Source with path, text and related friends.

Ah ha! Yes, that'd be nice. Maybe we could also combine it with oxc-project/backlog#94?

let source = Source::from_file(path);

This would initialize a Source with the provided path, SourceType as deduced from the path's file extension, and also read the file from file system (using fast SIMD UTF-8 validation). A one-stop shop!

(we'd also provide more complex methods to create Source from a String, override SourceType etc)

But you may make this smaller breaking API change first.

OK great. I'll do that now.