optional.js

Makes TypeScript/JavaScript code undefined/null safe!

Optional.js is a wrapper for undefined and null values in TypeScript/JavaScript which fixes problems with handling this values.

Reasons to use optional.js

• Eliminate errors correlated with undefined / null handling in code.
• Makes you aware of possible scenarios when value is undefined / null.
• Built in methods for handling undefined / null to reduce required checks.
• Makes code easier to read.

Change this:

const user: User = getUser(4);
if (user !== undefined) {
    console.log(user.name);
}

into this:

getUser(4).ifPresent(user => console.log(user.name))

Or this:

const users: User[] = getUsers();
const user: User = users.find(user => user.name == 'test');
if (user !== undefined) {
    console.log(user.name);
}

into this:

OptionalArray.ofArray(getAllUsers())
    .findOne(user => user.name == 'test')
    .ifPresent(user => console.log(user.name))

Features

• Contains known from Java Optional (Without stream()) and more.
• Contains useful methods which reduce boilerplate code for array operations.
• Written in TypeScript with type checking.
• No external dependencies.
• Small footprint.
• 100% code coverage.

Installation

Download from npm or from GitHub

Changelog

Changelog

Usage

Library consist of two main class/helpers

• Optional - Designed to handle null / undefined safety for single values.
  • Readme with usage examples of Optional
• OptionalArray - Designed to handle null / undefined safety for arrays.
  • Readme with usage examples of OptionalArray