@typescript-eslint/no-unsafe-function-type

You can call a value of type Function with any arguments, and the result is any, so TypeScript checks nothing about the call. Function also accepts classes, which throw when you call them without new.

Write the parameters and the return type instead.

This rule is on by default in TypeScript files.

Configure

On by default as a warning. To turn it off:

[lint.rules]
"@typescript-eslint/no-unsafe-function-type" = "off" # or "error"

Examples

Reported:

function onChange(listener: Function) {
  listener("name", 1, 2, 3);
}

Not reported:

function onChange(listener: (field: string) => void) {
  listener("name");
}

An interface that extends Function is reported too:

interface Handler extends Function {
  priority: number;
}

To accept any function at all, use a signature that every function matches:

function nameOf(task: (...args: never[]) => unknown) {
  return task.name;
}

Your own type named Function isn't reported:

import type { Function } from "./ast";

export function visit(node: Function) {}