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Description
I forget the term for function parameter type assignability being reversed from variable assignability. Seems whatever that is called is not happening here.
This TypeScript playground shows how it should work.
But in AS, a function type like () => void is not assignable to one like (i: i32) => void, although it should be fine (it is safe, because the type without any parameters can not do anything wrong with a passed argument.
But maybe I'm missing something: does WebAssembly allow passing an arg to a function without parameters (only to be ignored)? If so, then it should be fine to make it so in AS.
Input:
declare function foo(f: (t: i32) => void): void
export function fib(n: i32): i32 {
const f: () => void = () => {}
foo(f) // error
return 123
}Error:
ERROR TS2322: Type '() => void' is not assignable to type '(f32) => void'.
The error can be bypassed in certain cases, and the application will work fine:
declare function foo(f: (t: i32) => void): void
declare function log(s: string): void
export function fib(n: i32): i32 {
foo(() => {
log('test')
}) // no error, example Runs fine!
return 123
}