Add test showing lambda members are not kept by a keep all rule

Change-Id: I97ceeff4189ef97cc1b14affff7b4085c791b438

src/test/java/com/android/tools/r8/shaking/PreserveDesugaredLambdaTest.java

diff --git a/src/test/java/com/android/tools/r8/shaking/PreserveDesugaredLambdaTest.java b/src/test/java/com/android/tools/r8/shaking/PreserveDesugaredLambdaTest.java
new file mode 100644
index 0000000..a7e7538
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/shaking/PreserveDesugaredLambdaTest.java
@@ -0,0 +1,89 @@
+// Copyright (c) 2019, 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.shaking;
+
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertTrue;
+
+import com.android.tools.r8.CompilationFailedException;
+import com.android.tools.r8.R8TestCompileResult;
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestParametersCollection;
+import java.io.IOException;
+import java.util.concurrent.ExecutionException;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class PreserveDesugaredLambdaTest extends TestBase {
+
+  public interface Interface {
+    void computeTheFoo();
+  }
+
+  public static class A {
+    static void doFoo(Interface i) {
+      i.computeTheFoo();
+    }
+  }
+
+  public static class Main {
+    public static void main(String[] args) {
+      // The desugared lambda should be preserved.
+      A.doFoo(() -> System.out.println("Hello World!"));
+    }
+  }
+
+  private final TestParameters parameters;
+
+  @Parameters(name = "{0}")
+  public static TestParametersCollection data() {
+    return getTestParameters().withDexRuntimes().build();
+  }
+
+  public PreserveDesugaredLambdaTest(TestParameters parameters) {
+    this.parameters = parameters;
+  }
+
+  @Test
+  public void testKeepDesugaredLambdaMembers()
+      throws IOException, CompilationFailedException, ExecutionException {
+    R8TestCompileResult libraryCompileResult =
+        testForR8(parameters.getBackend())
+            .addProgramClasses(Interface.class, A.class)
+            .addKeepAllClassesRule()
+            .setMinApi(parameters.getRuntime())
+            .compile();
+    // A is not passed in to ensure the Enqueuer is not tracing through classpath to see the use of
+    // computeFoo().s
+    testForR8(parameters.getBackend())
+        .addProgramClasses(Main.class)
+        .addClasspathClasses(Interface.class)
+        .addLibraryFiles(TestBase.runtimeJar(parameters.getBackend()))
+        .addKeepAllClassesRule()
+        .setMinApi(parameters.getRuntime())
+        .compile()
+        .addRunClasspathFiles(libraryCompileResult.writeToZip())
+        .inspect(
+            codeInspector ->
+                assertTrue(
+                    codeInspector.allClasses().stream()
+                        .anyMatch(
+                            c -> {
+                              if (c.getOriginalName()
+                                  .contains("-$$Lambda$KeepDesugaredLambdaTest$Main")) {
+                                assertThat(c.uniqueMethodWithName("computeTheFoo"), isPresent());
+                                return true;
+                              }
+                              return false;
+                            })))
+        .run(parameters.getRuntime(), Main.class)
+        .assertSuccessWithOutputLines("Hello World!");
+  }
+}