gif.js

'use strict';

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

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

describe('GIF input', () => {
  it('GIF Buffer to JPEG Buffer', () =>
    sharp(fs.readFileSync(fixtures.inputGif))
      .resize(8, 4)
      .jpeg()
      .toBuffer({ resolveWithObject: true })
      .then(({ data, info }) => {
        assert.strictEqual(true, data.length > 0);
        assert.strictEqual(data.length, info.size);
        assert.strictEqual('jpeg', info.format);
        assert.strictEqual(8, info.width);
        assert.strictEqual(4, info.height);
      })
  );

  it('2 channel GIF file to PNG Buffer', () =>
    sharp(fixtures.inputGifGreyPlusAlpha)
      .resize(8, 4)
      .png()
      .toBuffer({ resolveWithObject: true })
      .then(({ data, info }) => {
        assert.strictEqual(true, data.length > 0);
        assert.strictEqual(data.length, info.size);
        assert.strictEqual('png', info.format);
        assert.strictEqual(8, info.width);
        assert.strictEqual(4, info.height);
        assert.strictEqual(4, info.channels);
      })
  );

  it('Animated GIF first page to PNG', () =>
    sharp(fixtures.inputGifAnimated)
      .toBuffer({ resolveWithObject: true })
      .then(({ data, info }) => {
        assert.strictEqual(true, data.length > 0);
        assert.strictEqual(data.length, info.size);
        assert.strictEqual('gif', info.format);
        assert.strictEqual(80, info.width);
        assert.strictEqual(80, info.height);
        assert.strictEqual(4, info.channels);
      })
  );

  it('Animated GIF all pages to PNG "toilet roll"', () =>
    sharp(fixtures.inputGifAnimated, { pages: -1 })
      .toBuffer({ resolveWithObject: true })
      .then(({ data, info }) => {
        assert.strictEqual(true, data.length > 0);
        assert.strictEqual(data.length, info.size);
        assert.strictEqual('gif', info.format);
        assert.strictEqual(80, info.width);
        assert.strictEqual(2400, info.height);
        assert.strictEqual(4, info.channels);
      })
  );

  it('GIF with reduced colours, no dither, low effort reduces file size', async () => {
    const original = await sharp(fixtures.inputJpg)
      .resize(120, 80)
      .gif()
      .toBuffer();

    const reduced = await sharp(fixtures.inputJpg)
      .resize(120, 80)
      .gif({
        colours: 128,
        dither: 0,
        effort: 1
      })
      .toBuffer();

    assert.strictEqual(true, reduced.length < original.length);
  });

  it('valid optimise', () => {
    assert.doesNotThrow(() => sharp().gif({ reoptimise: true }));
    assert.doesNotThrow(() => sharp().gif({ reoptimize: true }));
  });

  it('invalid reoptimise throws', () => {
    assert.throws(
      () => sharp().gif({ reoptimise: -1 }),
      /Expected boolean for gifReoptimise but received -1 of type number/
    );
    assert.throws(
      () => sharp().gif({ reoptimize: 'fail' }),
      /Expected boolean for gifReoptimise but received fail of type string/
    );
  });

  it('invalid loop throws', () => {
    assert.throws(() => {
      sharp().gif({ loop: -1 });
    });
    assert.throws(() => {
      sharp().gif({ loop: 65536 });
    });
  });

  it('invalid delay throws', () => {
    assert.throws(() => {
      sharp().gif({ delay: -1 });
    });
    assert.throws(() => {
      sharp().gif({ delay: [65536] });
    });
  });

  it('invalid colour throws', () => {
    assert.throws(() => {
      sharp().gif({ colours: 1 });
    });
    assert.throws(() => {
      sharp().gif({ colours: 'fail' });
    });
  });

  it('invalid effort throws', () => {
    assert.throws(() => {
      sharp().gif({ effort: 0 });
    });
    assert.throws(() => {
      sharp().gif({ effort: 'fail' });
    });
  });

  it('invalid dither throws', () => {
    assert.throws(() => {
      sharp().gif({ dither: 1.1 });
    });
    assert.throws(() => {
      sharp().gif({ effort: 'fail' });
    });
  });

  it('invalid interFrameMaxError throws', () => {
    assert.throws(
      () => sharp().gif({ interFrameMaxError: 33 }),
      /Expected number between 0.0 and 32.0 for interFrameMaxError but received 33 of type number/
    );
    assert.throws(
      () => sharp().gif({ interFrameMaxError: 'fail' }),
      /Expected number between 0.0 and 32.0 for interFrameMaxError but received fail of type string/
    );
  });

  it('invalid interPaletteMaxError throws', () => {
    assert.throws(
      () => sharp().gif({ interPaletteMaxError: 257 }),
      /Expected number between 0.0 and 256.0 for interPaletteMaxError but received 257 of type number/
    );
    assert.throws(
      () => sharp().gif({ interPaletteMaxError: 'fail' }),
      /Expected number between 0.0 and 256.0 for interPaletteMaxError but received fail of type string/
    );
  });

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

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

  it('should optimise file size via interFrameMaxError', async () => {
    const input = sharp(fixtures.inputGifAnimated, { animated: true });
    const before = await input.gif({ interFrameMaxError: 0 }).toBuffer();
    const after = await input.gif({ interFrameMaxError: 10 }).toBuffer();
    assert.strict(before.length > after.length);
  });

  it('should optimise file size via interPaletteMaxError', async () => {
    const input = sharp(fixtures.inputGifAnimated, { animated: true });
    const before = await input.gif({ interPaletteMaxError: 0 }).toBuffer();
    const after = await input.gif({ interPaletteMaxError: 100 }).toBuffer();
    assert.strict(before.length > after.length);
  });
});