jest-color

🃏🎨

A bundle of Jest matchers for testing and asserting colors

---

Problem

Testing colors with Jest is not simple. It should be as easy as .toBeColor

Solution

jest-color aims to add additional matchers to Jest's default ones that does just that

Contributing

If you've come here to help contribute - Sweet! Thanks! Take a look at the contributing and read the Code of Conduct docs as a way of getting started!

---

• Problem
• Solution
• Contributing
• Installation
• Setup
• Asymmetric matchers
• API
  • .toBeColor(color)
  • expect.color(color)
  • .toBeIndistinguishableFrom(color)
  • expect.indistinguishableFrom(color)
• LICENSE

Installation

With npm:

npm install -D jest-color

With yarn:

yarn add -D jest-color

Setup

Jest >v24

Add jest-color to your Jest setupFilesAfterEnv configuration. See for help

"jest": {
  "setupFilesAfterEnv": ["jest-color"]
}

Asymmetric matchers

All matchers described below have asymmetric variants. Example:

test("symmetric vs asymmetric", () => {
  expect("#7db2ceff").toBeColor(125, 178, 206);
  expect("#7db2ceff").toEqual(expect.color(125, 178, 206));
});

API

.toBeColor(object)

Accepts anything that color accepts and compares them to one another. It must be the exact same color.

expect("#7db2ceff").toBeColor(125, 178, 206); // true
expect("#72510e").toBeColor(114, 81, 14, 1); // true
expect([157, 204, 97]).toBeColor("#9dcc61"); // true
expect("hwb(60, 3%, 60%)").toBeColor("rgb(102, 102, 8)"); // true
expect("#cccc0866").toBeColor("hwb(60, 3%, 20%, 0.4)"); // true
expect("hsla(114, 60%, 39%, 0.32)").toBeColor([52, 159, 40, 0.32]); // true

expect("#7db2caaa").not.toBeColor(125, 178, 202); // true

expect.color(color)

The asymmetric variant of .toBeColor.

expect("#7db2ceff").toEqual(expect.color(125, 178, 206)); // true
expect("#72510e").toEqual(expect.color(114, 81, 14, 1)); // true
expect([157, 204, 97]).toEqual(expect.color("#9dcc61")); // true
expect("hwb(60, 3%, 60%)").toEqual(expect.color("rgb(102, 102, 8)")); // true
expect("#cccc0866").toEqual(expect.color("hwb(60, 3%, 20%, 0.4)")); // true
expect("hsla(114, 60%, 39%, 0.32)").toEqual(expect.color([52, 159, 40, 0.32])); // true

expect("#7db2caaa").toEqual(expect.not.color(125, 178, 202)); // true

.toBeIndistinguishableFrom(color)

Also accepts anything that color accepts. It compares them using THE POWER OF SCIENCE CIEDE2000 and if the Delta E is less than 1 it returns true.

expect.indistinguishableFrom(color)

The asymmetric variant of .toBeIndistinguishableFrom.

expect([50, 158, 38]).toEqual(expect.indistinguishableFrom(49, 155, 37)); // true
expect([217, 223, 214]).toEqual(
  expect.indistinguishableFrom("rgb(216, 222, 215)"),
); // true
expect("hwb(110, 84%, 13%)").toEqual(
  expect.indistinguishableFrom("hwb(111, 84%, 13%)"),
); // true

LICENSE

MIT