// If x is NaN, the result is NaN. assertEq(Math.trunc(NaN), NaN); // If x is −0, the result is −0. assertEq(Math.trunc(-0), -0); // If x is +0, the result is +0. assertEq(Math.trunc(+0), +0); // If x is +∞, the result is +∞. assertEq(Math.trunc(Infinity), Infinity); // If x is −∞, the result is −∞. assertEq(Math.trunc(-Infinity), -Infinity); // Other boundary cases. var MAX_NONINTEGER_VALUE = 4503599627370495.5; var TRUNC_MAX_NONINTEGER_VALUE = 4503599627370495; assertEq(Math.trunc(Number.MIN_VALUE), +0); assertEq(Math.trunc(ONE_MINUS_EPSILON), +0); assertEq(Math.trunc(ONE_PLUS_EPSILON), 1); assertEq(Math.trunc(MAX_NONINTEGER_VALUE), TRUNC_MAX_NONINTEGER_VALUE); assertEq(Math.trunc(Number.MAX_VALUE), Number.MAX_VALUE); assertEq(Math.trunc(-Number.MIN_VALUE), -0); assertEq(Math.trunc(-ONE_MINUS_EPSILON), -0); assertEq(Math.trunc(-ONE_PLUS_EPSILON), -1); assertEq(Math.trunc(-MAX_NONINTEGER_VALUE), -TRUNC_MAX_NONINTEGER_VALUE); assertEq(Math.trunc(-Number.MAX_VALUE), -Number.MAX_VALUE); // Other cases. for (var i = 1, f = 1.1; i < 20; i++, f += 1.0) assertEq(Math.trunc(f), i); for (var i = -1, f = -1.1; i > -20; i--, f -= 1.0) assertEq(Math.trunc(f), i); assertEq(Math.trunc(1e40 + 0.5), 1e40); assertEq(Math.trunc(1e300), 1e300); assertEq(Math.trunc(-1e300), -1e300); assertEq(Math.trunc(1e-300), 0); assertEq(Math.trunc(-1e-300), -0); assertEq(Math.trunc(+0.9999), +0); assertEq(Math.trunc(-0.9999), -0); reportCompare(0, 0, "ok");