simple-rust-tests/__wasm/wit-bindgen-sample/wit-bindgen/TODO.md

All generators

• handle support in exports

• push/pull-buffer support in exports

wasmtime

• buffer-in-buffer doesn't work. Doesn't work because we can't get a re-access of the transaction to add more buffers into it after-the-fact.

• Needs more testing on big-endian.

• Features from wiggle:

  • use GuestError::InFunc more liberally
    • stores/loads
    • try_from conversions
  • generate just the trait (??? what to do about wasmtime dep ???)

JS

• Is there a better representation for general variant types? Currently it's { tag: string, val: T } but that seems like it's probably sub-par. There's specializations for option<T> and enum variants, but that's it.

• Is there a better representation for flags than simply an integer?

• Should functions returning expected<T, E> get translated in JS to functions that return T and throw E?

• Adding imports to an import object is clunky because you need to also pass in a closure which extracts values from the raw instance. Unsure how to make this less clunky though.

• Needs more testing on big-endian. Specifically slice copies are probably not correct.

• Style with names needs to be respected, currently things are using to_snake_case but I think JS prefers camelCase?

• The bigint type is strict in that it does not accept plain number types to work with it. Should generated bindings be more flexible though and work with number in addition to bigint?

• Host-handle types are always ascribed as any but ideally we'd do better than that and assign them types. Maybe the type should be imported from somewhere else?

• Lifting/lowering of variants can almost surely use a more compressed technique which generates less code.

• Enums are handled in lowering as either strings or numbers, but should only numbers be handled here? Does anyone pass around strings as enum values?

• Exported handle types in JS aren't nominal. As of this writing they all only have a drop and a clone method so they're interchangeable from tsc's perspective. Ideally these would be nominal separate types.

• Imported handle types show up as any in TS, unsure how to plumb through actual types to get that actually typed.