#no-async-promise-finally

#Configuration

import { defineConfig, unicornPlugin } from '@rslint/core';

export default defineConfig([
  unicornPlugin.configs.recommended,
  {
    rules: {
      'unicorn/no-async-promise-finally': 'error',
    },
  },
]);

#Rule Details

Disallow async functions as Promise#finally() callbacks.

An async finalizer can replace the original promise outcome if it rejects. For example, when the original promise rejects and the async finalizer also rejects, the resulting promise rejects with the finalizer error rather than the original one.

The rule reports async callbacks passed directly to .finally(), as well as callbacks referenced through a local async function declaration or a const initializer.

Examples of incorrect code:

promise.finally(async () => {
  await cleanup();
});

async function cleanupAgain() {}
promise.finally(cleanupAgain);

Examples of correct code:

promise.finally(() => {
  cleanupSynchronously();
});

function cleanupAgain() {}
promise.finally(cleanupAgain);

Imported functions, member expressions, let bindings, and other dynamic callback references are intentionally ignored because the rule cannot locally prove that they are async.

#Options

This rule has no options. It is enabled at error severity in unicornPlugin.configs.recommended.

#Differences from upstream

Rslint preserves Unicorn v75.0.0's best-effort source-only behavior. When type information is available, a call is skipped only when the receiver is proven not to be Promise-like. any, unknown, TypeScript error types, and mixed Promise/non-Promise unions remain indeterminate and are therefore checked just like upstream.

Static computed property names use Rslint's canonical static string evaluator, so promise["finally"](...), template literals, and locally constant "finally" keys are recognized without a bespoke resolver.

#Original Documentation

• eslint-plugin-unicorn: no-async-promise-finally
• Source code