Javascript  |  54行  |  2.15 KB

// Copyright 2010 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
//       copyright notice, this list of conditions and the following
//       disclaimer in the documentation and/or other materials provided
//       with the distribution.
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//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// Tests the special cases specified by ES 15.8.2.17

function test(expected_sqrt, value) {
  assertEquals(expected_sqrt, Math.sqrt(value));
  if (isFinite(value)) {
    if (value === 0 && (1 / value) == -Infinity) {
      // Math.pow(-0, 0.5) must be zero, but Math.sqrt(-0) is -0.
      expected_sqrt = 0;
    }
    assertEquals(expected_sqrt, Math.pow(value, 0.5));
  }
}

// Simple sanity check
test(2, 4);
test(0.1, 0.01);

// Spec tests
test(NaN, NaN);
test(NaN, -1);
test(+0, +0);
test(-0, -0);
test(Infinity, Infinity);
// -Infinity is smaller than 0 so it should return NaN
test(NaN, -Infinity);