test/unit/math-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 { float64ToUint16, uint16ToFloat64 } = Arrow.util;

describe('Float16', () => {
    test('Uint16 to Float64 works', () => {

        const uNaN = 0x7E00 /* NaN */;
        const pInf = 0x7C00 /* 1/0 */;
        const nInf = 0xFC00 /*-1/0 */;
        let value = 0, expected = value;

        do {

            expected = value;

            // if exponent is all 1s, either Infinity or NaN
            if ((value & 0x7C00) === 0x7C00) {
                // if significand, must be NaN
                if (((value << 6) & 0xFFFF) !== 0) {
                    expected = uNaN;
                } else {
                    // otherwise  +/- Infinity
                    expected = (value >>> 15) !== 0 ? nInf : pInf;
                }
            }

            expect(float64ToUint16(uint16ToFloat64(value))).toEqual(expected);
        } while (++value < 65536);
    });
});