fix(es/codegen): Implement codegen for static import assertions

[andreubotella]

swc_ecma_codegen:

• Implement codegen for static import assertions.

swc_ecma_transforms_proposal:

• Modify the existing import_assertions transform to support assertions in exports.
• Add tests.

swc:

• Add a keep_import_assertions option to JscExperimental that will keep import assertions in the compiled output.

node-swc:

• Add a keepImportAssertions option to the typings for JscConfig.experimental.
• Also fix a typo in the typings where JscConfig.experimental was spelled as "experimetal".

Description:

Currently import assertions are correctly parsed if the input is TypeScript, or EcmaScript with import_assertions: true, but the codegen step strips them no matter what. This PR adds a keep_import_assertions option to JscConfig to keep them.

BREAKING CHANGE:

None

Related issue (if exists):

Fixes #2802.

[CLAassistant]

All committers have signed the CLA.

[RiESAEX]

looks like this will fix #2802 too

[kdy1]

Other changes except this LGTM. Thank you!

I think this can make users think it's an option to enable instead of to keep.

[kdy1]

Thank you!

[andreubotella]

Thank you!

Thank you for the review!

[guybedford]

This configuration doesn't seem to apply through the .swcrc file correctly currently in the Node.js CLI run, instead only when set manually via -C jsc.experimental.keepImportAssertions=true. Perhaps something was overlooked in this PR?

[kdy1]

@guybedford Ah, my bad. I think it's because there's no code to handle the field in

swc/crates/swc/src/config/mod.rs

Lines 985 to 991 in a4e93eb

	impl Merge for JscExperimental {
	fn merge(&mut self, from: &Self) {
	if self.plugins.is_none() {
	*self = from.clone();
	}
	}
	}