src/test/examplesJava17/backport/StrictMathBackportJava17Test.java

// Copyright (c) 2024, the R8 project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

package backport;

import com.android.tools.r8.TestBase;
import com.android.tools.r8.TestParameters;
import com.android.tools.r8.TestRuntime.CfVm;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.junit.runners.Parameterized.Parameter;
import org.junit.runners.Parameterized.Parameters;

@RunWith(Parameterized.class)
public class StrictMathBackportJava17Test extends TestBase {

  @Parameter(0)
  public TestParameters parameters;

  @Parameters(name = "{0}")
  public static Iterable<?> data() {
    return getTestParameters()
        .withDexRuntimes()
        .withCfRuntimesStartingFromIncluding(CfVm.JDK17)
        .withAllApiLevelsAlsoForCf()
        .build();
  }

  @Test
  public void test() throws Exception {
    testForDesugaring(parameters)
        .addInnerClassesAndStrippedOuter(getClass())
        .run(parameters.getRuntime(), TestClass.class)
        .assertSuccess();
  }

  public static class TestClass {

    public static void main(String[] args) {
      // The methods are actually from Java 15, but we can test them from Java 17.
      testAbsExactInteger();
      testAbsExactLong();
      // The methods are actually from Java 14, but we can test them from Java 17.
      testDecrementExactInteger();
      testDecrementExactLong();
      testIncrementExactInteger();
      testIncrementExactLong();
      testNegateExactInteger();
      testNegateExactLong();
    }

    private static void testAbsExactInteger() {
      assertEquals(42, StrictMath.absExact(42));
      assertEquals(42, StrictMath.absExact(-42));
      assertEquals(Integer.MAX_VALUE, StrictMath.absExact(Integer.MAX_VALUE));
      try {
        throw new AssertionError(StrictMath.absExact(Integer.MIN_VALUE));
      } catch (ArithmeticException expected) {

      }
    }

    private static void testAbsExactLong() {
      assertEquals(42L, StrictMath.absExact(42L));
      assertEquals(42L, StrictMath.absExact(-42L));
      assertEquals(Long.MAX_VALUE, StrictMath.absExact(Long.MAX_VALUE));
      try {
        throw new AssertionError(StrictMath.absExact(Long.MIN_VALUE));
      } catch (ArithmeticException expected) {

      }
    }

    private static void testDecrementExactInteger() {
      assertEquals(-1, StrictMath.decrementExact(0));
      assertEquals(Integer.MIN_VALUE, StrictMath.decrementExact(Integer.MIN_VALUE + 1));

      try {
        throw new AssertionError(StrictMath.decrementExact(Integer.MIN_VALUE));
      } catch (ArithmeticException expected) {
      }
    }

    private static void testDecrementExactLong() {
      assertEquals(-1L, StrictMath.decrementExact(0L));
      assertEquals(Long.MIN_VALUE, StrictMath.decrementExact(Long.MIN_VALUE + 1L));

      try {
        throw new AssertionError(StrictMath.decrementExact(Long.MIN_VALUE));
      } catch (ArithmeticException expected) {
      }
    }

    private static void testIncrementExactInteger() {
      assertEquals(1, StrictMath.incrementExact(0));
      assertEquals(Integer.MAX_VALUE, StrictMath.incrementExact(Integer.MAX_VALUE - 1));

      try {
        throw new AssertionError(StrictMath.incrementExact(Integer.MAX_VALUE));
      } catch (ArithmeticException expected) {
      }
    }

    private static void testIncrementExactLong() {
      assertEquals(1L, StrictMath.incrementExact(0L));
      assertEquals(Long.MAX_VALUE, StrictMath.incrementExact(Long.MAX_VALUE - 1L));

      try {
        throw new AssertionError(StrictMath.incrementExact(Long.MAX_VALUE));
      } catch (ArithmeticException expected) {
      }
    }

    private static void testNegateExactInteger() {
      assertEquals(0, StrictMath.negateExact(0));
      assertEquals(-1, StrictMath.negateExact(1));
      assertEquals(1, StrictMath.negateExact(-1));
      assertEquals(-2_147_483_647, StrictMath.negateExact(Integer.MAX_VALUE));

      try {
        throw new AssertionError(StrictMath.negateExact(Integer.MIN_VALUE));
      } catch (ArithmeticException expected) {
      }
    }

    private static void testNegateExactLong() {
      assertEquals(0L, StrictMath.negateExact(0L));
      assertEquals(-1L, StrictMath.negateExact(1L));
      assertEquals(1L, StrictMath.negateExact(-1L));
      assertEquals(-9_223_372_036_854_775_807L, StrictMath.negateExact(Long.MAX_VALUE));

      try {
        throw new AssertionError(StrictMath.negateExact(Long.MIN_VALUE));
      } catch (ArithmeticException expected) {
      }
    }

    private static void assertEquals(int expected, int actual) {
      if (expected != actual) {
        throw new AssertionError("Expected <" + expected + "> but was <" + actual + '>');
      }
    }

    private static void assertEquals(long expected, long actual) {
      if (expected != actual) {
        throw new AssertionError("Expected <" + expected + "> but was <" + actual + '>');
      }
    }
  }
}