An argument without a type confuses automatic type inference for a generic function

[oleg-slapdash]

Bug Report

I am sorry for a dry bug report, I am not sure why it happens and what area of TS this is concerned but I have a repro in hopes this would be fixed.

🔎 Search Terms

No idea, really.

🕗 Version & Regression Information

• This is the behavior in every version I tried.

⏯ Playground Link

Playground link with relevant code

💻 Code

export const data = {
  fails: castType({
    // NOTE: It fails if this function has an argument
    subscribe: (_foo) => ({ foo: "bar" } as const),
    resolve: (data) => data.foo,
  }),
  works: castType({
    // NOTE: It works if argument is not defined
    subscribe: () => ({ foo: "bar" } as const),
    resolve: (data) => data.foo,
  }),
};

export function castType<TPayload>(resolver: {
  subscribe: (foo: boolean) => TPayload;
  resolve?: (parent: TPayload) => any;
}) {
  return resolver;
}

🙁 Actual behavior

It fails to determine the correct type in a generic if an argument is specified.

🙂 Expected behavior

It should determine the correct types for a generic.

[MartinJohns]

Duplicate of #43371.