voluptasquisquam/src/util/__tests__/validateArrayOfChannels.js

Image processing and manipulation in JavaScript

import {Image} from 'test/common';
import {validateArrayOfChannels} from '../channel';
import 'should';

describe('we check the validateArrayOfChannels method', function () {
    it('check for a RGB image', function () {
        let image = new Image(2, 2, {
            kind: 'RGB'
        });

        validateArrayOfChannels(image, {
            channels: ['r', 'g', 'b']}).should.eql([0, 1, 2]);
        validateArrayOfChannels(image, {channels: 'r'}).should.eql([0]);
        validateArrayOfChannels(image, {channels: 'b'}).should.eql([2]);
        validateArrayOfChannels(image, {channels: 1}).should.eql([1]);
        validateArrayOfChannels(image, {channels: [0, 1, 2]}).should.eql([0, 1, 2]);
        validateArrayOfChannels(image).should.eql([0, 1, 2]);
        validateArrayOfChannels(image, {allowAlpha: true}).should.eql([0, 1, 2]);
        validateArrayOfChannels(image, {allowAlpha: false}).should.eql([0, 1, 2]);
        validateArrayOfChannels(image, {defaultAlpha: true}).should.eql([0, 1, 2]);
        (function () {
            validateArrayOfChannels(image, {channels: 'a'});
        }).should.throw(/does not contain alpha/);
        (function () {
            validateArrayOfChannels(image, {channels: ['r', 'a']});
        }).should.throw(/does not contain alpha/);
    });

    it('check for a RGBA image', function () {
        let image = new Image(2, 2, {
            kind: 'RGBA'
        });

        validateArrayOfChannels(image, {channels: ['r', 'g', 'b']}).should.eql([0, 1, 2]);
        validateArrayOfChannels(image, {channels: 'r'}).should.eql([0]);
        validateArrayOfChannels(image, {channels: 'b'}).should.eql([2]);
        validateArrayOfChannels(image, {channels: 1}).should.eql([1]);
        validateArrayOfChannels(image, {channels: [0, 1, 2]}).should.eql([0, 1, 2]);
        validateArrayOfChannels(image).should.eql([0, 1, 2]);
        validateArrayOfChannels(image, {defaultAlpha: true}).should.eql([0, 1, 2, 3]);
        validateArrayOfChannels(image, {defaultAlpha: false}).should.eql([0, 1, 2]);
        validateArrayOfChannels(image, {allowAlpha: true, defaultAlpha: false}).should.eql([0, 1, 2]);
        validateArrayOfChannels(image, {allowAlpha: true, defaultAlpha: true}).should.eql([0, 1, 2, 3]);
        validateArrayOfChannels(image, {channels: 'a'}).should.eql([3]);
        validateArrayOfChannels(image, {channels: ['r', 'a']}).should.eql([0, 3]);
        (function () {
            validateArrayOfChannels(image, {channels: 'a', allowAlpha: false});
        }).should.throw(/alpha channel may not be selected/);
    });

    it('check for a GreyA image', function () {
        let image = new Image(2, 2, {
            kind: 'GREYA'
        });

        validateArrayOfChannels(image, {channels: 'a'}).should.eql([1]);
        validateArrayOfChannels(image, {channels: 1}).should.eql([1]);
        validateArrayOfChannels(image).should.eql([0]);
        validateArrayOfChannels(image, {defaultAlpha: true}).should.eql([0, 1]);
        validateArrayOfChannels(image, {defaultAlpha: false}).should.eql([0]);
        (function () {
            validateArrayOfChannels(image, {channels: ['r']});
        }).should.throw(/undefined channel/);
        (function () {
            validateArrayOfChannels(image, {allowAlpha: false, channels: ['a']});
        }).should.throw(/alpha channel may not be selected/);
    });

});