dcevm/dcevm/src/test/java7/com/github/dcevm/test/fields/StaticFieldHandleTest.java

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
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package com.github.dcevm.test.fields;

import com.github.dcevm.test.TestUtil;
import org.junit.After;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Ignore;
import org.junit.Test;

import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.MethodType;

import static com.github.dcevm.test.util.HotSwapTestHelper.__toVersion__;
import static com.github.dcevm.test.util.HotSwapTestHelper.__version__;
import static org.junit.Assert.assertEquals;

/**
 * Test for replacing field with MethodHandle pointing to it.
 *
 * @author Ivan Dubrov
 */
public class StaticFieldHandleTest {

  // Version 0
  public static class A {
    public static int fieldA;
    public static int fieldB;
  }

  // Version 1 (fields swapped)
  public static class A___1 {
    public static int fieldB;
    public static int fieldA;
  }

  // Version 2 (fields removed)
  public static class A___2 {
  }

  // Version 3 (field type changed)
  public static class A___3 {
    public String fieldA;
    public int fieldB;
  }

  @Before
  @After
  public void setUp() throws Exception {
    __toVersion__(0);
  }

  @Test
  public void testStaticFieldChangeOrder() throws Throwable {
    MethodHandle handle = MethodHandles.publicLookup().findStaticGetter(A.class, "fieldA", int.class);

    A.fieldA = 3;
    A.fieldB = 5;
    assertEquals(3, handle.invoke());

    // Swap fields A and B
    __toVersion__(1);
    assertEquals(3, handle.invoke());
  }

  @Test
  @Ignore
  public void testStaticFieldRemoved() throws Throwable {
    MethodHandle handle = MethodHandles.publicLookup().findStaticGetter(A.class, "fieldA", int.class);

    A.fieldA = 3;
    A.fieldB = 5;
    assertEquals(3, handle.invoke());

    // Remove fieldA
    __toVersion__(2);

    handle.invoke();
  }

  @Test
  @Ignore
  public void testStaticFieldTypeChange() throws Throwable {
    MethodHandle handle = MethodHandles.publicLookup().findStaticGetter(A.class, "fieldA", int.class);

    A.fieldA = 3;
    A.fieldB = 5;
    assertEquals(3, handle.invoke());

    // Remove fieldA
    __toVersion__(3);

    handle.invoke();
  }
}