@typescript-eslint/no-unsafe-call

The compiler lets you call an any with any arguments. It doesn't check that the value is a function, and the result is any again. If the value isn't a function, you find out from a TypeError when the code runs.

The rule reports calls, new, and tagged templates. It also reports a value of type Function, which says you can call something but not which arguments it takes. A type that can't be resolved, for example from a missing import, counts as any.

bun lint --type-aware turns this rule on in TypeScript files.

Configure

Off by default. This rule needs types, so turning it on makes bun lint type check your code first.

[lint.rules]
"@typescript-eslint/no-unsafe-call" = "error" # or "warn"

Examples

Reported:

function run(plugin: any, handler: Function) {
  plugin();
  plugin.setup();
  new plugin.Worker();
  handler();
}

Not reported:

interface Plugin {
  setup(): void;
  Worker: new () => object;
}

function run(plugin: Plugin, handler: () => void) {
  plugin.setup();
  new plugin.Worker();
  handler();
}

For a value you know nothing about, use unknown and check it before the call:

function stop(controller: unknown) {
  if (controller instanceof AbortController) {
    controller.abort();
  }
}

When not to use it

In a codebase that's still moving from JavaScript to TypeScript, any is everywhere and the reports drown out everything else. Turn the rule on once most values have real types.