inline function implicit any support

[ron23]

I think it makes sense to not add any to inline functions and it's better to leave them for TS to manually infer. It makes migration a bit easier and safer. Example:

// utils.ts  =< TS file
function addOne(input: number): number {
  return input + 1;
}

// foo.js
function f(input) {
  input.map(x => addOne(x))
}

### after ts-migrate runs (foo.ts)

function f(input: any) {
  input.map((x: any) => addOne(x));   // <= I want to keep x implicit
}

// when I type `input` I don't get error on the inline
function g(input: string[]) {
  input.map((x: any) => addOne(x)); // no error
}

// What I want: adding types to f will infer correctly and detect an error
function f(input: string[]) {
  input.map(x => addOne(x)); // Argument of type 'string' is not assignable to parameter of type 'number'.(2345)
}

[edsrzf]

The reason that ts-migrate adds the any is because TypeScript is still flagging an error with the noImplicitAny: true option. This link might make it clearer: https://www.typescriptlang.org/play?#code/GYVwdgxgLglg9mABAQwCaoPJgKYAoZgAOIUAXImCALYBG2ATgJTmW0OIDeAUIovdlBD0kBYlEQBqRAEYA3FwC+XLqEiwEiYPiIlyyMAE9GnHolEkAdFWSFcAD0QBeAHwp0WPHcaN5CoA

You're correct that this is a little annoying when you do decide to add the : string[] annotation and the annotation for the map callback becomes unnecessary.

I'm not sure of the best way to solve this, though. It would be nice if the TypeScript compiler could report unnecessary annotations, maybe.

[ron23]

I see, yea that makes sense. Thanks. I'll close.