checko

There is a new sherrif in town to check your values for type and range errors! :police_car:

Motivation

I needed predicates and assertions for type and range checking that:

• have a fast and simple implementation,
• only check for what their name implies,
• yield standard errors,
• yield readable stack traces,
• can be included when needed,
• can be used to create custom predicates and assertions and
• do.not.use.this.style()

Installation

npm install checko

Example

Import any of the exported predicates and assertions and simply use them.

const expectArray = require('checko/exports/expectArray')
// or
const expectArray = require('checko').expectArray
// or
import expectArray from 'checko/exports/expectArray'
// or
import { expectArray } from 'checko'

expectArray('this is not an array')

Tip: This package publishes source maps. Use source-map-support to utilize them during development to get clearer stack traces.

Documentation

For some 'expect' variants there is no 'is' variant because the language itself provides an operator.

Predicate	Assertion
value === expected	expectEqual(expected, value)
isArray(value)	expectArray(value)

All files in exports/ can be directly included. Implementations for each predicate and assertion can be found there. Examples are shown in the accompanying .test.js.

Due to the simple nature of this package (except for the isDeepEqual(expected, value) implementation) there is no further documentation. If this is a problem, please let me know.