nanoassert

What is nanoassert?

nanoassert is a minimalistic assertion library for JavaScript. It provides a simple and lightweight way to perform assertions in your code, ensuring that conditions hold true and throwing errors when they do not. This can be particularly useful for debugging and validating code logic.

What are nanoassert's main functionalities?

Basic Assertion

This feature allows you to perform a basic assertion to check if a condition is true. If the condition is false, an error with the provided message will be thrown.

const assert = require('nanoassert');

let x = 5;
assert(x === 5, 'x should be 5');

Custom Error Messages

You can provide custom error messages that will be displayed when an assertion fails. This helps in understanding what went wrong in the code.

const assert = require('nanoassert');

let y = 10;
assert(y > 5, 'y should be greater than 5');

Type Checking

nanoassert can be used to perform type checking, ensuring that variables are of the expected type.

const assert = require('nanoassert');

let z = 'hello';
assert(typeof z === 'string', 'z should be a string');

Other packages similar to nanoassert

chai

Chai is a BDD / TDD assertion library for node and the browser that can be delightfully paired with any javascript testing framework. It provides a rich set of assertions and is more feature-rich compared to nanoassert.

assert

The 'assert' module from Node.js provides a set of assertion functions for verifying invariants. It is built into Node.js and offers more comprehensive functionality compared to nanoassert.

should

Should.js is an expressive, readable, and powerful assertion library for node and the browser. It extends the Object prototype with a single non-enumerable property, making it more expressive but also more intrusive compared to nanoassert.

README

nanoassert

Nanoscale assertion module

Usage

var assert = require('nanoassert')

assert(a !== b, `${a} !== ${b}`)

API

assert(declaration, [message])

Assert that declaration is truthy otherwise throw AssertionError with optional message. In Javascript runtimes that use v8, you will get a nicer stack trace with this error. If you want friendlier messages you can use template strings to show the assertion made like in the example above.

Why

I like to write public facing code very defensively, but have reservations about the size incurred by the assert module. I only use the top-level assert method anyway.

nanoassert@^1.1.0

Docs for the previous version, which is used by many modules on npm, can be found here

Install

npm install nanoassert

License

ISC