node-optional

Optional Class

The Optional class is a utility that helps you handle values that may or may not be present. It provides a safer alternative to null checks and improves code readability.

Features

• of: Creates an Optional instance with a value or null.
• isPresent: Checks if a value is present.
• isOptional: Checks if the value is null.
• get: Retrieves the value if present, throws an error otherwise.
• orElseThrow: Returns the value if present, or throws a custom exception with a message.

Installation

Install the package via npm:

npm install optional-class

Usage

Here’s how to use the Optional class in your TypeScript project:

import Optional from "optional-class";

// Creating an Optional with a value
const optionalValue = Optional.of("Hello, World!");

if (optionalValue.isPresent()) {
  console.log(optionalValue.get()); // Output: Hello, World!
}

// Creating an Optional with a null value
const emptyValue = Optional.of(null);

console.log(emptyValue.isOptional()); // Output: true

// Handling a non-present value with a custom exception
try {
  emptyValue.orElseThrow(Error, "No value present!");
} catch (e) {
  console.error(e.message); // Output: No value present!
}

API

static of<T>(value: T | null): Optional<T>

Creates an Optional instance with the provided value. If null is passed, the Optional will represent an empty value.

isPresent(): boolean

Returns true if the Optional contains a value, otherwise false.

isOptional(): boolean

Returns true if the Optional is empty (i.e., the value is null).

get(): T

Returns the contained value if present. Throws an error if the value is null.

orElseThrow<E extends Error>(exception: new (...args: any[]) => E, message: string): T

Returns the value if present. If the value is null, throws the specified exception with the provided message.

License

This project is licensed under the MIT License.