#no-single-promise-in-promise-methods

#Configuration

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

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

#Rule Details

Disallow passing single-element arrays to Promise.all(), Promise.any(), or Promise.race().

Promise combinators coordinate multiple inputs. Passing just one value can hide a missing promise or introduce unnecessary array handling.

Examples of incorrect code for this rule:

const foo = await Promise.all([promise]);
const bar = await Promise.any([promise]);
const baz = await Promise.race([promise]);
const pending = Promise.all([nonPromise]);

Examples of correct code for this rule:

const foo = await promise;
const pending = Promise.resolve(nonPromise);
const results = await Promise.all(promises);
const first = await Promise.any([promise, anotherPromise]);
const [{ value, reason }] = await Promise.allSettled([promise]);

#Fixes and Suggestions

Awaited Promise.race() calls can be replaced with the single value. Calls without await offer suggestions to use the value directly or switch to Promise.resolve(). Promise.any() is reported without fixes or suggestions because replacing it changes how rejections are handled.

Promise.all() produces an array, so it is only automatically unwrapped when the awaited result is discarded, destructured into one identifier, or accessed at index 0 in a variable initializer or assignment:

const [value] = await Promise.all([promise]);
// Fixed to:
const value = await promise;

Comments that would be lost prevent unwrapping. When available, the Promise.resolve() suggestion preserves comments. Other Promise.all() calls are reported without a fix or suggestions.

The rule checks direct, non-optional calls on the identifier Promise. Computed methods, such as Promise['race'](), and globalThis.Promise are not checked. Promise.allSettled() is excluded because its result contains settlement details.

#Options

This rule has no options.

#Differences from upstream

• Promise.any([promise]) keeps its diagnostic but has no fixes or suggestions. Unlike eslint-plugin-unicorn v77.0.0, rslint preserves the AggregateError and its .errors array when the input rejects. For example, await Promise.any([Promise.reject('failure')]) must not become await Promise.reject('failure').
• Promise.all() is not automatically unwrapped when JSDoc @type or @satisfies constrains the original promise or tuple result. This includes annotations on destructuring declarations and casts around the call, awaited result, or destructuring assignment. For example, /** @satisfies {[number]} */ const [value] = await Promise.all([Promise.resolve(1)]) keeps the tuple result required by its annotation, avoiding a new type error under checkJs. Annotations on the scalar result of (await Promise.all([promise]))[0] still allow the fix.
• Direct-value suggestions keep parentheses around members whose receiver starts with an object, function, or class expression. For example, Promise.race([{ value: promise }.value]) becomes ({ value: promise }.value), which remains valid as a statement or an arrow function body.

#Original Documentation

• eslint-plugin-unicorn: no-single-promise-in-promise-methods
• Source code