SWC Community•4d ago

Use `swc_ecma_compat_es2017::async_to_generator` for conditional async transformations

Hey team, I've been working on a plugin that takes async functions and transforms them to generators for usage with mobx flows. I've gotten reasonably far but came across: https://docs.rs/swc_ecma_compat_es2017/latest/src/swc_ecma_compat_es2017/async_to_generator.rs.html#39-46 This transformation is exactly what i've been aiming for and would make for a far more robust solution, as what i've written so far handles the conditional cases as I expect. The issue i'm running into is that I'd like to instantiate the AsyncToGenerator visitor to visit_children_with it when the conditions are met to perform this transformation, but async_to_generator returns Pass which does not satisfy VisitMut Would it be reasonable to export a function that does work this way from swc_ecma_compat_es2017? Or am I down the wrong path here?

async_to_generator.rs - source

Source of the Rust file src/async_to_generator.rs.

3 Replies

CodexOP•4d ago

I suppose I'm mainly wanting the:

AsyncToGenerator {
    c,
    fn_state: None,
    in_subclass: false,
    unresolved_ctxt: SyntaxContext::empty().apply_mark(unresolved_mark),
}

AsyncToGenerator {
    c,
    fn_state: None,
    in_subclass: false,
    unresolved_ctxt: SyntaxContext::empty().apply_mark(unresolved_mark),
}

Without the visit_mut_pass call so I can then use it similarly 🤔 does this even make sense?

kdy1•4d ago

Nope. I think you should just copy the code.

CodexOP•3d ago

Sweet, the only problem with that is the usage of the private API helper and helper_expr macros, but I suppose I can copy those too

Gaming

Programming

Use `swc_ecma_compat_es2017::async_to_generator` for conditional async transformations

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