polished/lib/color/getContrast.js

A lightweight toolset for writing styles in Javascript.

"use strict";

exports.__esModule = true;
exports["default"] = getContrast;
var _getLuminance = _interopRequireDefault(require("./getLuminance"));
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { "default": obj }; }
/**
 * Returns the contrast ratio between two colors based on
 * [W3's recommended equation for calculating contrast](http://www.w3.org/TR/WCAG20/#contrast-ratiodef).
 *
 * @example
 * const contrastRatio = getContrast('#444', '#fff');
 */
function getContrast(color1, color2) {
  var luminance1 = (0, _getLuminance["default"])(color1);
  var luminance2 = (0, _getLuminance["default"])(color2);
  return parseFloat((luminance1 > luminance2 ? (luminance1 + 0.05) / (luminance2 + 0.05) : (luminance2 + 0.05) / (luminance1 + 0.05)).toFixed(2));
}
module.exports = exports.default;