maybe-types

A collection of types for Maybe in TypeScript.

Types

Core Types

• MaybePromise<T> - Represents a value that may or may not be a promise. Useful for functions that can return either synchronous or asynchronous values.
• UnwrapPromise<T> - Extracts the inner type from a Promise, returning the unwrapped type if it's a promise, otherwise returns the original type.

Function Types

• Fn<R, P> - A function type with return type R and parameters P (defaults to any).
• AsyncFn<R, P> - An asynchronous function type with return type R and parameters P.
• MaybeFunction<T, P> - Represents either a value T or a function that returns T with parameters P.
• MaybeFn<T, P> - Alias for MaybeFunction<T, P>.
• MaybeAsyncFunction<T, P, Promised> - Represents either a value, a function returning a promise, or a function that may return synchronously or asynchronously based on the Promised flag.
• UnwrapFunction<T> - Extracts the return type from a function type.
• UnwrapAsyncFunction<T> - Extracts the return type from an async function or MaybeAsyncFunction type.

Primitive & Collection Types

• MaybeArray<T> - Represents either a single value T or an array of T.
• MaybeNumeric<T> - Represents either a number, bigint, or the type T (defaults to string). Useful for numeric string conversions.
• Numeric - Union type of number | bigint.
• MaybeDate - Represents a Date object, a timestamp number, or a date string.
• MaybeRegex - Represents either a RegExp object or a regex pattern string.
• MaybeFalsy - Union of all falsy values: false | null | undefined | "" | 0 | void.

Usage

Install package:

# npm
npm install maybe-types

# yarn
yarn add maybe-types

# pnpm
pnpm install maybe-types

Import:

import type { MaybePromise } from "maybe-types";

async function fn(arg: string): MaybePromise<string> {
  if (arg === "foo") {
    return "bar";
  }
  return Promise.resolve("baz");
}

async function getPromise(): Promise<string> {
  return promise = await fn("foo");
}

Development

• Clone this repository
• Install latest LTS version of Node.js
• Enable Corepack using corepack enable
• Install dependencies using pnpm install
• Run interactive tests using pnpm test

License

Made with 💛

Published under MIT License.