message: gradientColorAtPercent unit tests
diff: import { expect } from 'chai';
  import { describe, it } from 'mocha';
  -import { generateContrastColors } from '../../src/helpers/color';
  +import { generateContrastColors, gradientColorAtPercent } from '../../src/helpers/color';
  describe('generateContrastColors', () => {
  it('should work', () => {
  @@ -122,3 +122,26 @@ describe('generateContrastColors', () => {
  expect(generateContrastColors.bind(null, 'rgba(10, 20, 30, 1.0, 1.0)')).to.throw();
  });
  });
  +
  +describe('gradientColorAtPercent', () => {
  + it('0%', () => {
  + expect(gradientColorAtPercent('rgb(255, 255, 255)', 'rgb(0, 0, 0)', 0)).to.be.equal('rgba(255, 255, 255, 1)');
  + expect(gradientColorAtPercent('rgba(255, 255, 255, 1)', 'rgba(0, 0, 0, 0)', 0)).to.be.equal('rgba(255, 255, 255, 1)');
  + expect(gradientColorAtPercent('#ffffff', '#000000', 0)).to.be.equal('rgba(255, 255, 255, 1)');
  + expect(gradientColorAtPercent('#fff', '#000', 0)).to.be.equal('rgba(255, 255, 255, 1)');
  + });
  +
  + it('50%', () => {
  + expect(gradientColorAtPercent('rgb(255, 255, 255)', 'rgb(0, 0, 0)', 0.5)).to.be.equal('rgba(128, 128, 128, 1)');
  + expect(gradientColorAtPercent('rgba(255, 255, 255, 1)', 'rgba(0, 0, 0, 0)', 0.5)).to.be.equal('rgba(128, 128, 128, 0.5)');
  + expect(gradientColorAtPercent('#ffffff', '#000000', 0.5)).to.be.equal('rgba(128, 128, 128, 1)');
  + expect(gradientColorAtPercent('#fff', '#000', 0.5)).to.be.equal('rgba(128, 128, 128, 1)');
  + });
  +
  + it('100%', () => {
  + expect(gradientColorAtPercent('rgb(255, 255, 255)', 'rgb(0, 0, 0)', 1)).to.be.equal('rgba(0, 0, 0, 1)');
  + expect(gradientColorAtPercent('rgba(255, 255, 255, 1)', 'rgba(0, 0, 0, 0)', 1)).to.be.equal('rgba(0, 0, 0, 0)');
  + expect(gradientColorAtPercent('#ffffff', '#000000', 1)).to.be.equal('rgba(0, 0, 0, 1)');
  + expect(gradientColorAtPercent('#fff', '#000', 1)).to.be.equal('rgba(0, 0, 0, 1)');
  + });
  +});
  