@bigfishtv/cockpit/src/utils/colorUtils.spec.js

import { interpolateGradient } from './colorUtils.js'

describe('interpolateGradient', () => {
	it('should return midpoint gray with range of 3', () => {
		const gradientMapMarkers = [
			{
				position: 0,
				alpha: 1,
				color: [0, 0, 0],
			},
			{
				position: 1,
				alpha: 1,
				color: [255, 255, 255],
			},
		]

		const expected = [0, 0, 0, 255, 128, 128, 128, 255, 255, 255, 255, 255]
		expect(interpolateGradient(gradientMapMarkers, 3)).toEqual(expected)
	})

	it('should resolve colors if markers are not on end points', () => {
		const gradientMapMarkers = [
			{
				position: 0,
				alpha: 1,
				color: [0, 0, 0],
			},
			{
				position: 0.5,
				alpha: 1,
				color: [255, 255, 255],
			},
		]

		const expected = [0, 0, 0, 255, 255, 255, 255, 255, 255, 255, 255, 255]
		expect(interpolateGradient(gradientMapMarkers, 3)).toEqual(expected)
	})

	it('should return array with lenth of 4x the range provided', () => {
		const gradientMapMarkers = [
			{
				position: 0,
				alpha: 1,
				color: [0, 0, 0],
			},
			{
				position: 1,
				alpha: 1,
				color: [255, 255, 255],
			},
		]
		expect(interpolateGradient(gradientMapMarkers, 12).length).toEqual(4 * 12)
		expect(interpolateGradient(gradientMapMarkers, 255).length).toEqual(4 * 255)
	})
})