ts-result-type

Result type - inspired by Rust's Result type

This Result module offers a mechanism for error handling using the Result type, an effective pattern popular in languages like Rust. This module introduces two main constructs, Ok and Err, for expressive error handling without exceptions.

Table of Contents

• Installation
• Usage
• Testing
• License

Installation

npm install ts-result-type

pnpm add ts-result-type

yarn add ts-result-type

Usage

To represent a successful computation:

import type { Result } from 'ts-result-type'
import { Ok, Err } from 'ts-result-type'

const result = Ok(5)
console.log(result.isOk) // true

Examples:

• match: Process the value if it's an Ok.

const result = Ok(5)
const output = result.match(value => value * 2, _ => 0)
console.log(output) // 10

• getValueOrDefault: Get the contained value or a default.

const result = Ok(5)
console.log(result.getValueOrDefault(10)) // 5

• getValueOrCompute: Get the contained value or a default.

const result: Result<number, string> = Err("400")
console.log(result.getValueOrCompute(err => +err)) // 400

• map: Transform the value inside an Ok.

const result = Ok(5)
const transformed = result.map(value => value.toString())
console.log(transformed.match(val => val, _ => "")) // "5"

• mapErr: Transform the error inside an Err.

const errorResult = Err('Error!')
const transformed = errorResult.mapErr(error => error.length)
console.log(transformed.match(_ => 0, errorLength => errorLength)) // 6

Testing

To run tests:

npm run test

License

This project is licensed under the MIT License. See LICENSE.md for more details.