sharp/test/unit/webp.js

'use strict';

const fs = require('fs');
const assert = require('assert');

const sharp = require('../../');
const fixtures = require('../fixtures');

describe('WebP', function () {
  it('WebP output', function (done) {
    sharp(fixtures.inputJpg)
      .resize(320, 240)
      .toFormat(sharp.format.webp)
      .toBuffer(function (err, data, info) {
        if (err) throw err;
        assert.strictEqual(true, data.length > 0);
        assert.strictEqual('webp', info.format);
        assert.strictEqual(320, info.width);
        assert.strictEqual(240, info.height);
        done();
      });
  });

  it('Invalid WebP quality throws error', function () {
    assert.throws(function () {
      sharp().webp({ quality: 101 });
    });
  });

  it('Invalid WebP alpha quality throws error', function () {
    assert.throws(function () {
      sharp().webp({ alphaQuality: 101 });
    });
  });

  it('should work for webp alpha quality', function (done) {
    sharp(fixtures.inputPngAlphaPremultiplicationSmall)
      .webp({ alphaQuality: 80 })
      .toBuffer(function (err, data, info) {
        if (err) throw err;
        assert.strictEqual(true, data.length > 0);
        assert.strictEqual('webp', info.format);
        fixtures.assertSimilar(fixtures.expected('webp-alpha-80.webp'), data, done);
      });
  });

  it('should work for webp lossless', function (done) {
    sharp(fixtures.inputPngAlphaPremultiplicationSmall)
      .webp({ lossless: true })
      .toBuffer(function (err, data, info) {
        if (err) throw err;
        assert.strictEqual(true, data.length > 0);
        assert.strictEqual('webp', info.format);
        fixtures.assertSimilar(fixtures.expected('webp-lossless.webp'), data, done);
      });
  });

  it('should work for webp near-lossless', function (done) {
    sharp(fixtures.inputPngAlphaPremultiplicationSmall)
      .webp({ nearLossless: true, quality: 50 })
      .toBuffer(function (err50, data50, info50) {
        if (err50) throw err50;
        assert.strictEqual(true, data50.length > 0);
        assert.strictEqual('webp', info50.format);
        fixtures.assertSimilar(fixtures.expected('webp-near-lossless-50.webp'), data50, done);
      });
  });

  it('should use near-lossless when both lossless and nearLossless are specified', function (done) {
    sharp(fixtures.inputPngAlphaPremultiplicationSmall)
      .webp({ nearLossless: true, quality: 50, lossless: true })
      .toBuffer(function (err50, data50, info50) {
        if (err50) throw err50;
        assert.strictEqual(true, data50.length > 0);
        assert.strictEqual('webp', info50.format);
        fixtures.assertSimilar(fixtures.expected('webp-near-lossless-50.webp'), data50, done);
      });
  });

  it('should produce a larger file size using smartSubsample', () =>
    sharp(fixtures.inputJpg)
      .resize(320, 240)
      .webp({ smartSubsample: false })
      .toBuffer()
      .then(withoutSmartSubsample =>
        sharp(fixtures.inputJpg)
          .resize(320, 240)
          .webp({ smartSubsample: true })
          .toBuffer()
          .then(withSmartSubsample => {
            assert.strictEqual(true, withSmartSubsample.length > withoutSmartSubsample.length);
          })
      )
  );

  it('invalid smartSubsample throws', () => {
    assert.throws(() => {
      sharp().webp({ smartSubsample: 1 });
    });
  });

  it('should produce a smaller file size with increased reductionEffort', () =>
    sharp(fixtures.inputJpg)
      .resize(320, 240)
      .webp()
      .toBuffer()
      .then(reductionEffort4 =>
        sharp(fixtures.inputJpg)
          .resize(320, 240)
          .webp({ reductionEffort: 6 })
          .toBuffer()
          .then(reductionEffort6 => {
            assert.strictEqual(true, reductionEffort4.length > reductionEffort6.length);
          })
      )
  );

  it('invalid reductionEffort throws', () => {
    assert.throws(() => {
      sharp().webp({ reductionEffort: true });
    });
  });

  it('out of range reductionEffort throws', () => {
    assert.throws(() => {
      sharp().webp({ reductionEffort: -1 });
    });
  });

  it('invalid pageHeight throws', () => {
    assert.throws(() => {
      sharp().webp({ pageHeight: 0 });
    });
  });

  it('invalid loop throws', () => {
    assert.throws(() => {
      sharp().webp({ loop: -1 });
    });

    assert.throws(() => {
      sharp().webp({ loop: 65536 });
    });
  });

  it('invalid delay throws', () => {
    assert.throws(() => {
      sharp().webp({ delay: [-1] });
    });

    assert.throws(() => {
      sharp().webp({ delay: [65536] });
    });
  });

  it('should double the number of frames with default delay', async () => {
    const original = await sharp(fixtures.inputWebPAnimated, { pages: -1 }).metadata();
    const updated = await sharp(fixtures.inputWebPAnimated, { pages: -1 })
      .webp({ pageHeight: original.pageHeight / 2 })
      .toBuffer()
      .then(data => sharp(data, { pages: -1 }).metadata());

    assert.strictEqual(updated.pages, original.pages * 2);
    assert.strictEqual(updated.pageHeight, original.pageHeight / 2);
    assert.deepStrictEqual(updated.delay, [...original.delay, ...Array(9).fill(120)]);
  });

  it('should limit animation loop', async () => {
    const updated = await sharp(fixtures.inputWebPAnimated, { pages: -1 })
      .webp({ loop: 3 })
      .toBuffer()
      .then(data => sharp(data, { pages: -1 }).metadata());

    assert.strictEqual(updated.loop, 3);
  });

  it('should change delay between frames', async () => {
    const original = await sharp(fixtures.inputWebPAnimated, { pages: -1 }).metadata();

    const expectedDelay = [...Array(original.pages).fill(40)];
    const updated = await sharp(fixtures.inputWebPAnimated, { pages: -1 })
      .webp({ delay: expectedDelay })
      .toBuffer()
      .then(data => sharp(data, { pages: -1 }).metadata());

    assert.deepStrictEqual(updated.delay, expectedDelay);
  });

  it('should work with streams when only animated is set', function (done) {
    fs.createReadStream(fixtures.inputWebPAnimated)
      .pipe(sharp({ animated: true }))
      .webp({ lossless: true })
      .toBuffer(function (err, data, info) {
        if (err) throw err;
        assert.strictEqual(true, data.length > 0);
        assert.strictEqual('webp', info.format);
        fixtures.assertSimilar(fixtures.inputWebPAnimated, data, done);
      });
  });

  it('should work with streams when only pages is set', function (done) {
    fs.createReadStream(fixtures.inputWebPAnimated)
      .pipe(sharp({ pages: -1 }))
      .webp({ lossless: true })
      .toBuffer(function (err, data, info) {
        if (err) throw err;
        assert.strictEqual(true, data.length > 0);
        assert.strictEqual('webp', info.format);
        fixtures.assertSimilar(fixtures.inputWebPAnimated, data, done);
      });
  });
});