@poppinss/colors

Colors

Wrapper on top of Kleur with support for testing color calls.

This module is a wrapper on top of Kleur to make it easier to test the output generated using the kleur API. The API exposed is 100% the same as kleur.

Table of contents

• Why use this module?
• Usage
• Raw Implementation

Why use this module?

Have you ever wonder, how to test the output of function calls like the following?

import { bgRed, white } from 'kleur'
assert.equal(bgRed().white('Error'), 'Error') // fails

Well, you can make use of modules like strip-ansi to strip the ansi codes and get back the plain string.

import { bgRed, white } from 'kleur'
import stripAnsi from 'strip-ansi'

assert.equal(stripAnsi(bgRed().white('Error')), 'Error') // passes

However, this module takes a step forward with a fake colors API, that you can use during testing to reliably test the output.

import { FakeColors } from '@poppinss/colors'
const colors = new FakeColors()

assert.equal(colors.bgRed().white('Error'), 'bgRed(white(Error))') // passes

Usage

Install the package from npm registry as follows:

npm i @poppinss/colors

# yarn
yarn add @poppinss/colors

and then use it as follows:

import { Colors } from '@poppinss/colors'
const colors = new Colors()

// API same as kleur from here

When wring tests, you can make your code rely on FakeColors object instead of the Colors object. For example:

import { FakeColors } from '@poppinss/colors'
const colors = new FakeColors()

// API same as kleur from here

Raw Implementation

The Raw implementation exposes the same API as kleur, but does not apply any formatting/colors to the output string. You can use the raw implementation when the terminal does not support colors. For example:

import { Colors, Raw } from '@poppinss/colors'
import { level } from 'color-support'

const colors = level > 0 ? new Colors() : new Raw()
colors.red('hello world')

Finally, there is a method called getBest to get the best available implementation instance for your runtime.

import { getBest } from '@poppinss/colors'
const colors = getBest(false)

The getBest method returns following outputs

• An instance of Raw when the terminal does not supports colors.
• An instance of FakeColors when the first argument passed to the method is true.
• Otherwise returns an instance of Colors.