binary-test.js 8.23 KB
/* global describe, it */

var assert = require('assert');
var BN = require('../').BN;

describe('BN.js/Binary', function () {
  describe('.shl()', function () {
    it('should shl numbers', function () {
      // TODO(indutny): add negative numbers when the time will come
      assert.equal(new BN('69527932928').shln(13).toString(16),
        '2060602000000');
      assert.equal(new BN('69527932928').shln(45).toString(16),
        '206060200000000000000');
    });

    it('should ushl numbers', function () {
      assert.equal(new BN('69527932928').ushln(13).toString(16),
        '2060602000000');
      assert.equal(new BN('69527932928').ushln(45).toString(16),
        '206060200000000000000');
    });
  });

  describe('.shr()', function () {
    it('should shr numbers', function () {
      // TODO(indutny): add negative numbers when the time will come
      assert.equal(new BN('69527932928').shrn(13).toString(16),
        '818180');
      assert.equal(new BN('69527932928').shrn(17).toString(16),
        '81818');
      assert.equal(new BN('69527932928').shrn(256).toString(16),
        '0');
    });

    it('should ushr numbers', function () {
      assert.equal(new BN('69527932928').ushrn(13).toString(16),
        '818180');
      assert.equal(new BN('69527932928').ushrn(17).toString(16),
        '81818');
      assert.equal(new BN('69527932928').ushrn(256).toString(16),
        '0');
    });
  });

  describe('.bincn()', function () {
    it('should increment bit', function () {
      assert.equal(new BN(0).bincn(1).toString(16), '2');
      assert.equal(new BN(2).bincn(1).toString(16), '4');
      assert.equal(new BN(2).bincn(1).bincn(1).toString(16),
        new BN(2).bincn(2).toString(16));
      assert.equal(new BN(0xffffff).bincn(1).toString(16), '1000001');
      assert.equal(new BN(2).bincn(63).toString(16),
        '8000000000000002');
    });
  });

  describe('.imaskn()', function () {
    it('should mask bits in-place', function () {
      assert.equal(new BN(0).imaskn(1).toString(16), '0');
      assert.equal(new BN(3).imaskn(1).toString(16), '1');
      assert.equal(new BN('123456789', 16).imaskn(4).toString(16), '9');
      assert.equal(new BN('123456789', 16).imaskn(16).toString(16), '6789');
      assert.equal(new BN('123456789', 16).imaskn(28).toString(16), '3456789');
    });

    it('should not mask when number is bigger than length', function () {
      assert.equal(new BN(0xe3).imaskn(56).toString(16), 'e3');
      assert.equal(new BN(0xe3).imaskn(26).toString(16), 'e3');
    });
  });

  describe('.testn()', function () {
    it('should support test specific bit', function () {
      [
        'ff',
        'ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff'
      ].forEach(function (hex) {
        var bn = new BN(hex, 16);
        var bl = bn.bitLength();

        for (var i = 0; i < bl; ++i) {
          assert.equal(bn.testn(i), true);
        }

        // test off the end
        assert.equal(bn.testn(bl), false);
      });

      var xbits = '01111001010111001001000100011101' +
        '11010011101100011000111001011101' +
        '10010100111000000001011000111101' +
        '01011111001111100100011110000010' +
        '01011010100111010001010011000100' +
        '01101001011110100001001111100110' +
        '001110010111';

      var x = new BN(
        '23478905234580795234378912401239784125643978256123048348957342'
      );
      for (var i = 0; i < x.bitLength(); ++i) {
        assert.equal(x.testn(i), (xbits.charAt(i) === '1'), 'Failed @ bit ' + i);
      }
    });

    it('should have short-cuts', function () {
      var x = new BN('abcd', 16);
      assert(!x.testn(128));
    });
  });

  describe('.and()', function () {
    it('should and numbers', function () {
      assert.equal(new BN('1010101010101010101010101010101010101010', 2)
        .and(new BN('101010101010101010101010101010101010101', 2))
        .toString(2), '0');
    });

    it('should and numbers of different limb-length', function () {
      assert.equal(
        new BN('abcd0000ffff', 16)
          .and(new BN('abcd', 16)).toString(16),
        'abcd');
    });
  });

  describe('.iand()', function () {
    it('should iand numbers', function () {
      assert.equal(new BN('1010101010101010101010101010101010101010', 2)
        .iand(new BN('101010101010101010101010101010101010101', 2))
        .toString(2), '0');
      assert.equal(new BN('1000000000000000000000000000000000000001', 2)
        .iand(new BN('1', 2))
        .toString(2), '1');
      assert.equal(new BN('1', 2)
        .iand(new BN('1000000000000000000000000000000000000001', 2))
        .toString(2), '1');
    });
  });

  describe('.or()', function () {
    it('should or numbers', function () {
      assert.equal(new BN('1010101010101010101010101010101010101010', 2)
        .or(new BN('101010101010101010101010101010101010101', 2))
        .toString(2), '1111111111111111111111111111111111111111');
    });

    it('should or numbers of different limb-length', function () {
      assert.equal(
        new BN('abcd00000000', 16)
          .or(new BN('abcd', 16)).toString(16),
        'abcd0000abcd');
    });
  });

  describe('.ior()', function () {
    it('should ior numbers', function () {
      assert.equal(new BN('1010101010101010101010101010101010101010', 2)
        .ior(new BN('101010101010101010101010101010101010101', 2))
        .toString(2), '1111111111111111111111111111111111111111');
      assert.equal(new BN('1000000000000000000000000000000000000000', 2)
        .ior(new BN('1', 2))
        .toString(2), '1000000000000000000000000000000000000001');
      assert.equal(new BN('1', 2)
        .ior(new BN('1000000000000000000000000000000000000000', 2))
        .toString(2), '1000000000000000000000000000000000000001');
    });
  });

  describe('.xor()', function () {
    it('should xor numbers', function () {
      assert.equal(new BN('11001100110011001100110011001100', 2)
        .xor(new BN('1100110011001100110011001100110', 2))
        .toString(2), '10101010101010101010101010101010');
    });
  });

  describe('.ixor()', function () {
    it('should ixor numbers', function () {
      assert.equal(new BN('11001100110011001100110011001100', 2)
        .ixor(new BN('1100110011001100110011001100110', 2))
        .toString(2), '10101010101010101010101010101010');
      assert.equal(new BN('11001100110011001100110011001100', 2)
        .ixor(new BN('1', 2))
        .toString(2), '11001100110011001100110011001101');
      assert.equal(new BN('1', 2)
        .ixor(new BN('11001100110011001100110011001100', 2))
        .toString(2), '11001100110011001100110011001101');
    });

    it('should and numbers of different limb-length', function () {
      assert.equal(
        new BN('abcd0000ffff', 16)
          .xor(new BN('abcd', 16)).toString(16),
        'abcd00005432');
    });
  });

  describe('.setn()', function () {
    it('should allow single bits to be set', function () {
      assert.equal(new BN(0).setn(2, true).toString(2), '100');
      assert.equal(new BN(0).setn(27, true).toString(2),
        '1000000000000000000000000000');
      assert.equal(new BN(0).setn(63, true).toString(16),
        new BN(1).iushln(63).toString(16));
      assert.equal(new BN('1000000000000000000000000001', 2).setn(27, false)
        .toString(2), '1');
      assert.equal(new BN('101', 2).setn(2, false).toString(2), '1');
    });
  });

  describe('.notn()', function () {
    it('should allow bitwise negation', function () {
      assert.equal(new BN('111000111', 2).notn(9).toString(2),
        '111000');
      assert.equal(new BN('000111000', 2).notn(9).toString(2),
        '111000111');
      assert.equal(new BN('111000111', 2).notn(9).toString(2),
        '111000');
      assert.equal(new BN('000111000', 2).notn(9).toString(2),
        '111000111');
      assert.equal(new BN('111000111', 2).notn(32).toString(2),
        '11111111111111111111111000111000');
      assert.equal(new BN('000111000', 2).notn(32).toString(2),
        '11111111111111111111111111000111');
      assert.equal(new BN('111000111', 2).notn(68).toString(2),
        '11111111111111111111111111111111' +
        '111111111111111111111111111000111000');
      assert.equal(new BN('000111000', 2).notn(68).toString(2),
        '11111111111111111111111111111111' +
        '111111111111111111111111111111000111');
    });
  });
});