attempt

INFO

Important: This function is not suitable for async functions (functions that return a Promise). When passing an async function, it will return [null, Promise<T>], but won't catch any errors if the Promise is rejected later.

For handling async functions, it is recommended to use the attemptAsync function instead.

Attempts to execute a function and returns a tuple containing either the result or an error.

Signature

function attempt<T, E>(func: () => T): [null, T] | [E, null];

Parameters

• func (() => T): The function to attempt to execute.

Returns

([null, T] | [E, null]): A tuple where:

• On success: [null, T] - First element is null, second is the result.
• On error: [E, null] - First element is the caught error, second is null.

Examples

import { attempt } from 'es-toolkit/function';

// If the function succeeds, it returns [null, function return value] tuple.
const [error, result] = attempt(() => 42);
// [null, 42]

// If an error occurs, it returns [error thrown by the function, null] tuple.
const [error, result] = attempt(() => {
  throw new Error('Something went wrong');
});
// [Error, null]

// Using generic types lets you specify the type of the error and return value.
const [error, names] = attempt<string[], Error>(() => ['Alice', 'Bob']);
// `error` is inferred as `Error` type, `names` is inferred as `string[]` type.