js/test/unit/bit-tests.ts

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// to you under the Apache License, Version 2.0 (the
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//
//   http://www.apache.org/licenses/LICENSE-2.0
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import * as Arrow from 'apache-arrow';
const { BitIterator, getBool } = Arrow.util;

describe('Bits', () => {
    test('BitIterator produces correct bits for single byte', () => {
        const byte = new Uint8Array([0b1111_0000]);
        expect([...new BitIterator(byte, 0, 8, null, getBool)]).toEqual(
            [false, false, false, false, true, true, true, true]);

        expect([...new BitIterator(byte, 2, 5, null, getBool)]).toEqual(
            [false, false, true, true, true]);
    });

    test('BitIterator produces correct bits for multiple bytes', () => {
        const byte = new Uint8Array([0b1111_0000, 0b1010_1010]);
        expect([...new BitIterator(byte, 0, 16, null, getBool)]).toEqual(
            [false, false, false, false, true, true, true, true,
             false, true, false, true, false, true, false, true]);

        expect([...new BitIterator(byte, 2, 11, null, getBool)]).toEqual(
            [false, false, true, true, true, true,
             false, true, false, true, false]);
    });
});