yahoo/pngjs-image

// Copyright 2015 Yahoo! Inc.
// Copyrights licensed under the Mit License. See the accompanying LICENSE file for terms.

var testGen = require('../../testGen');
var expect = require('chai').expect;

describe('Histogram', function () {

    describe('15 colors', function () {

        testGen.addDecodeTests({
            resourceGroup: ['ancillary', 'histogram'],
            resourceFile: 'ch1n3p04',
            imageCheck: true,

            chunkTypes: ['gAMA', 'hIST', 'PLTE'],

            headerCheck: true,
            width: 32,
            height: 32,
            bitDepth: 4,
            colorType: 3,
            filter: 0,
            compression: 0,
            interlace: 0
        });

        it('should have volatile data', function () {
            expect(this.data.volatile).to.be.not.undefined;
        });

        it('should have a histogram', function () {
            expect(this.data.volatile.histogram).to.be.not.undefined;
        });

        it('should have a length of 15 histogram values', function () {
            expect(this.data.volatile.histogram).to.be.an('array');
            expect(this.data.volatile.histogram.length).to.be.equal(15);
        });

        it('should have histogram values', function () {
            expect(this.data.volatile.histogram).to.be.deep.equal([
                64, 112, 48, 96, 96, 32, 32, 80, 16, 128, 64, 16, 48, 80, 112
            ]);
        });

        it('should have the same length as the PLTE chunk', function () {
            expect(this.data.volatile.histogram.length).to.be.equal(this.data.volatile.paletteColors.length);
        });
    });

    describe('256 colors', function () {

        testGen.addDecodeTests({
            resourceGroup: ['ancillary', 'histogram'],
            resourceFile: 'ch2n3p08',
            imageCheck: true,

            chunkTypes: ['gAMA', 'hIST', 'PLTE'],

            headerCheck: true,
            width: 32,
            height: 32,
            bitDepth: 8,
            colorType: 3,
            filter: 0,
            compression: 0,
            interlace: 0
        });

        it('should have volatile data', function () {
            expect(this.data.volatile).to.be.not.undefined;
        });

        it('should have a histogram', function () {
            expect(this.data.volatile.histogram).to.be.not.undefined;
        });

        it('should have a length of 256 histogram values', function () {
            expect(this.data.volatile.histogram).to.be.an('array');
            expect(this.data.volatile.histogram.length).to.be.equal(256);
        });

        it('should have the same length as the PLTE chunk', function () {
            expect(this.data.volatile.histogram.length).to.be.equal(this.data.volatile.paletteColors.length);
        });
    });
});