diff options
Diffstat (limited to 'guava-tests/test/com/google/common/math/IntMathTest.java')
| -rw-r--r-- | guava-tests/test/com/google/common/math/IntMathTest.java | 145 |
1 files changed, 32 insertions, 113 deletions
diff --git a/guava-tests/test/com/google/common/math/IntMathTest.java b/guava-tests/test/com/google/common/math/IntMathTest.java index dcfd8a9..7f773ea 100644 --- a/guava-tests/test/com/google/common/math/IntMathTest.java +++ b/guava-tests/test/com/google/common/math/IntMathTest.java @@ -23,7 +23,6 @@ import static com.google.common.math.MathTesting.EXPONENTS; import static com.google.common.math.MathTesting.NEGATIVE_INTEGER_CANDIDATES; import static com.google.common.math.MathTesting.NONZERO_INTEGER_CANDIDATES; import static com.google.common.math.MathTesting.POSITIVE_INTEGER_CANDIDATES; -import static com.google.common.math.TestPlatform.intsCanGoOutOfRange; import static java.math.BigInteger.valueOf; import static java.math.RoundingMode.FLOOR; import static java.math.RoundingMode.UNNECESSARY; @@ -54,58 +53,48 @@ public class IntMathTest extends TestCase { @GwtIncompatible("pow()") public void testConstantsPowersOf10() { - for (int i = 0; i < IntMath.powersOf10.length - 1; i++) { - assertEquals(IntMath.pow(10, i), IntMath.powersOf10[i]); - } - } - - @GwtIncompatible("BigIntegerMath") // TODO(cpovirk): GWT-enable BigIntegerMath - public void testMaxLog10ForLeadingZeros() { - for (int i = 0; i < Integer.SIZE; i++) { - assertEquals( - BigIntegerMath.log10(BigInteger.ONE.shiftLeft(Integer.SIZE - i), FLOOR), - IntMath.maxLog10ForLeadingZeros[i]); + for (int i = 0; i < IntMath.POWERS_OF_10.length; i++) { + assertEquals(IntMath.pow(10, i), IntMath.POWERS_OF_10[i]); } } @GwtIncompatible("BigIntegerMath") // TODO(cpovirk): GWT-enable BigIntegerMath public void testConstantsHalfPowersOf10() { - for (int i = 0; i < IntMath.halfPowersOf10.length; i++) { - assert IntMath.halfPowersOf10[i] + for (int i = 0; i < IntMath.HALF_POWERS_OF_10.length; i++) { + assert IntMath.HALF_POWERS_OF_10[i] == Math.min(Integer.MAX_VALUE, BigIntegerMath.sqrt(BigInteger.TEN.pow(2 * i + 1), FLOOR).longValue()); } } @GwtIncompatible("BigIntegerMath") // TODO(cpovirk): GWT-enable BigIntegerMath - public void testConstantsBiggestBinomials() { - for (int k = 0; k < IntMath.biggestBinomials.length; k++) { - assertTrue(fitsInInt(BigIntegerMath.binomial(IntMath.biggestBinomials[k], k))); - assertTrue(IntMath.biggestBinomials[k] == Integer.MAX_VALUE - || !fitsInInt(BigIntegerMath.binomial(IntMath.biggestBinomials[k] + 1, k))); + public void testConstantsBiggestBinomials(){ + for (int k = 0; k < IntMath.BIGGEST_BINOMIALS.length; k++) { + assertTrue(fitsInInt(BigIntegerMath.binomial(IntMath.BIGGEST_BINOMIALS[k], k))); + assertTrue(IntMath.BIGGEST_BINOMIALS[k] == Integer.MAX_VALUE + || !fitsInInt(BigIntegerMath.binomial(IntMath.BIGGEST_BINOMIALS[k] + 1, k))); // In the first case, any int is valid; in the second, we want to test that the next-bigger // int overflows. } assertFalse( fitsInInt(BigIntegerMath.binomial( - 2 * IntMath.biggestBinomials.length, IntMath.biggestBinomials.length))); + 2 * IntMath.BIGGEST_BINOMIALS.length, IntMath.BIGGEST_BINOMIALS.length))); } - + @GwtIncompatible("sqrt") public void testPowersSqrtMaxInt() { assertEquals(IntMath.sqrt(Integer.MAX_VALUE, FLOOR), IntMath.FLOOR_SQRT_MAX_INT); } - @GwtIncompatible("java.math.BigInteger") public void testIsPowerOfTwo() { for (int x : ALL_INTEGER_CANDIDATES) { // Checks for a single bit set. - BigInteger bigX = BigInteger.valueOf(x); - boolean expected = (bigX.signum() > 0) && (bigX.bitCount() == 1); + boolean expected = x > 0 & (x & (x - 1)) == 0; assertEquals(expected, IntMath.isPowerOfTwo(x)); } } + @GwtIncompatible("log2") public void testLog2ZeroAlwaysThrows() { for (RoundingMode mode : ALL_ROUNDING_MODES) { try { @@ -115,6 +104,7 @@ public class IntMathTest extends TestCase { } } + @GwtIncompatible("log2") public void testLog2NegativeAlwaysThrows() { for (int x : NEGATIVE_INTEGER_CANDIDATES) { for (RoundingMode mode : ALL_ROUNDING_MODES) { @@ -127,6 +117,7 @@ public class IntMathTest extends TestCase { } // Relies on the correctness of BigIntegrerMath.log2 for all modes except UNNECESSARY. + @GwtIncompatible("BigIntegerMath") // TODO(cpovirk): GWT-enable BigIntegerMath public void testLog2MatchesBigInteger() { for (int x : POSITIVE_INTEGER_CANDIDATES) { for (RoundingMode mode : ALL_SAFE_ROUNDING_MODES) { @@ -136,6 +127,7 @@ public class IntMathTest extends TestCase { } // Relies on the correctness of isPowerOfTwo(int). + @GwtIncompatible("log2") public void testLog2Exact() { for (int x : POSITIVE_INTEGER_CANDIDATES) { // We only expect an exception if x was not a power of 2. @@ -263,41 +255,36 @@ public class IntMathTest extends TestCase { } } + @GwtIncompatible("-2147483648/1 expected=2147483648") public void testDivNonZero() { for (int p : NONZERO_INTEGER_CANDIDATES) { for (int q : NONZERO_INTEGER_CANDIDATES) { for (RoundingMode mode : ALL_SAFE_ROUNDING_MODES) { - // Skip some tests that fail due to GWT's non-compliant int implementation. - // TODO(cpovirk): does this test fail for only some rounding modes or for all? - if (p == -2147483648 && q == -1 && intsCanGoOutOfRange()) { - continue; - } int expected = new BigDecimal(valueOf(p)).divide(new BigDecimal(valueOf(q)), 0, mode).intValue(); - assertEquals(p + "/" + q, force32(expected), IntMath.divide(p, q, mode)); + assertEquals(p + "/" + q, expected, IntMath.divide(p, q, mode)); } } } } + @GwtIncompatible("-2147483648/-1 not expected to divide evenly") public void testDivNonZeroExact() { for (int p : NONZERO_INTEGER_CANDIDATES) { for (int q : NONZERO_INTEGER_CANDIDATES) { - // Skip some tests that fail due to GWT's non-compliant int implementation. - if (p == -2147483648 && q == -1 && intsCanGoOutOfRange()) { - continue; - } boolean dividesEvenly = (p % q) == 0; + try { assertEquals(p + "/" + q, p, IntMath.divide(p, q, UNNECESSARY) * q); - assertTrue(p + "/" + q + " not expected to divide evenly", dividesEvenly); + assertTrue(p + "/" + q + " expected to divide evenly", dividesEvenly); } catch (ArithmeticException e) { - assertFalse(p + "/" + q + " expected to divide evenly", dividesEvenly); + assertFalse(p + "/" + q + " not expected to divide evenly", dividesEvenly); } } } } + @GwtIncompatible("pow()") public void testZeroDivIsAlwaysZero() { for (int q : NONZERO_INTEGER_CANDIDATES) { for (RoundingMode mode : ALL_ROUNDING_MODES) { @@ -306,6 +293,7 @@ public class IntMathTest extends TestCase { } } + @GwtIncompatible("pow()") public void testDivByZeroAlwaysFails() { for (int p : ALL_INTEGER_CANDIDATES) { for (RoundingMode mode : ALL_ROUNDING_MODES) { @@ -432,13 +420,14 @@ public class IntMathTest extends TestCase { } } + @GwtIncompatible("-2147483648^1 expected=2147483648") public void testCheckedPow() { for (int b : ALL_INTEGER_CANDIDATES) { for (int k : EXPONENTS) { BigInteger expectedResult = valueOf(b).pow(k); boolean expectedSuccess = fitsInInt(expectedResult); try { - assertEquals(b + "^" + k, force32(expectedResult.intValue()), IntMath.checkedPow(b, k)); + assertEquals(b + "^" + k, expectedResult.intValue(), IntMath.checkedPow(b, k)); assertTrue(b + "^" + k + " should have succeeded", expectedSuccess); } catch (ArithmeticException e) { assertFalse(b + "^" + k + " should have failed", expectedSuccess); @@ -448,6 +437,7 @@ public class IntMathTest extends TestCase { } // Depends on the correctness of BigIntegerMath.factorial. + @GwtIncompatible("BigIntegerMath") // TODO(cpovirk): GWT-enable BigIntegerMath public void testFactorial() { for (int n = 0; n <= 50; n++) { BigInteger expectedBig = BigIntegerMath.factorial(n); @@ -456,6 +446,7 @@ public class IntMathTest extends TestCase { } } + @GwtIncompatible("factorial") public void testFactorialNegative() { for (int n : NEGATIVE_INTEGER_CANDIDATES) { try { @@ -501,87 +492,15 @@ public class IntMathTest extends TestCase { } } - @GwtIncompatible("java.math.BigInteger") - public void testMean() { - // Odd-sized ranges have an obvious mean - assertMean(2, 1, 3); - - assertMean(-2, -3, -1); - assertMean(0, -1, 1); - assertMean(1, -1, 3); - assertMean((1 << 30) - 1, -1, Integer.MAX_VALUE); - - // Even-sized ranges should prefer the lower mean - assertMean(2, 1, 4); - assertMean(-3, -4, -1); - assertMean(0, -1, 2); - assertMean(0, Integer.MIN_VALUE + 2, Integer.MAX_VALUE); - assertMean(0, 0, 1); - assertMean(-1, -1, 0); - assertMean(-1, Integer.MIN_VALUE, Integer.MAX_VALUE); - - // x == y == mean - assertMean(1, 1, 1); - assertMean(0, 0, 0); - assertMean(-1, -1, -1); - assertMean(Integer.MIN_VALUE, Integer.MIN_VALUE, Integer.MIN_VALUE); - assertMean(Integer.MAX_VALUE, Integer.MAX_VALUE, Integer.MAX_VALUE); - - // Exhaustive checks - for (int x : ALL_INTEGER_CANDIDATES) { - for (int y : ALL_INTEGER_CANDIDATES) { - assertMean(x, y); - } - } - } - - /** - * Helper method that asserts the arithmetic mean of x and y is equal - * to the expectedMean. - */ - private static void assertMean(int expectedMean, int x, int y) { - assertEquals("The expectedMean should be the same as computeMeanSafely", - expectedMean, computeMeanSafely(x, y)); - assertMean(x, y); - } - - /** - * Helper method that asserts the arithmetic mean of x and y is equal - * to the result of computeMeanSafely. - */ - private static void assertMean(int x, int y) { - int expectedMean = computeMeanSafely(x, y); - assertEquals(expectedMean, IntMath.mean(x, y)); - assertEquals("The mean of x and y should equal the mean of y and x", - expectedMean, IntMath.mean(y, x)); - } - - /** - * Computes the mean in a way that is obvious and resilient to - * overflow by using BigInteger arithmetic. - */ - private static int computeMeanSafely(int x, int y) { - BigInteger bigX = BigInteger.valueOf(x); - BigInteger bigY = BigInteger.valueOf(y); - BigDecimal bigMean = new BigDecimal(bigX.add(bigY)) - .divide(BigDecimal.valueOf(2), BigDecimal.ROUND_FLOOR); - // parseInt blows up on overflow as opposed to intValue() which does not. - return Integer.parseInt(bigMean.toString()); - } - - private static boolean fitsInInt(BigInteger big) { + private boolean fitsInInt(BigInteger big) { return big.bitLength() <= 31; } - + @GwtIncompatible("NullPointerTester") - public void testNullPointers() { + public void testNullPointers() throws Exception { NullPointerTester tester = new NullPointerTester(); tester.setDefault(int.class, 1); + tester.setDefault(RoundingMode.class, FLOOR); tester.testAllPublicStaticMethods(IntMath.class); } - - private static int force32(int value) { - // GWT doesn't consistently overflow values to make them 32-bit, so we need to force it. - return value & 0xffffffff; - } } |