src/test/java/com/android/tools/r8/classmerging/horizontal/interfaces/DisjointFunctionalInterfacesWithSameNameAndDifferentReturnTypeMergingTest.java

// Copyright (c) 2021, 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 com.android.tools.r8.classmerging.horizontal.interfaces;

import com.android.tools.r8.NoUnusedInterfaceRemoval;
import com.android.tools.r8.NoVerticalClassMerging;
import com.android.tools.r8.TestBase;
import com.android.tools.r8.TestParameters;
import com.android.tools.r8.TestParametersCollection;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;

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

  private final TestParameters parameters;

  @Parameterized.Parameters(name = "{0}")
  public static TestParametersCollection data() {
    return getTestParameters().withAllRuntimesAndApiLevels().build();
  }

  public DisjointFunctionalInterfacesWithSameNameAndDifferentReturnTypeMergingTest(
      TestParameters parameters) {
    this.parameters = parameters;
  }

  @Test
  public void test() throws Exception {
    testForR8(parameters.getBackend())
        .addInnerClasses(getClass())
        .addKeepMainRule(Main.class)
        // TODO(b/173990042): We should be able to merge I and J.
        .addHorizontallyMergedClassesInspector(
            inspector -> inspector.assertClassesNotMerged(I.class, J.class))
        .enableNoUnusedInterfaceRemovalAnnotations()
        .enableNoVerticalClassMergingAnnotations()
        .setMinApi(parameters.getApiLevel())
        .compile()
        .run(parameters.getRuntime(), Main.class)
        .assertSuccessWithOutputLines("I", "J");
  }

  static class Main {

    public static void main(String[] args) {
      System.out.println(((I) () -> "I").f());
      System.out.println(((J) () -> "J").f());
    }
  }

  @NoUnusedInterfaceRemoval
  @NoVerticalClassMerging
  interface I {
    Object f();
  }

  @NoUnusedInterfaceRemoval
  @NoVerticalClassMerging
  interface J {
    String f();
  }
}