Test record field pruning

Bug: 197081367
Change-Id: I701f4973b2afebaf2406986779e0a980a95db6b9

src/test/examplesJava17/records/RecordShrinkField.java

diff --git a/src/test/examplesJava17/records/RecordShrinkField.java b/src/test/examplesJava17/records/RecordShrinkField.java
new file mode 100644
index 0000000..b3cd366
--- /dev/null
+++ b/src/test/examplesJava17/records/RecordShrinkField.java
@@ -0,0 +1,21 @@
+// 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 records;
+
+public class RecordShrinkField {
+
+  record Person(String name, int age, int unused) {
+    Person(String name, int age) {
+      this(name, age, -1);
+    }
+  }
+
+  public static void main(String[] args) {
+    Person jane = new Person("Jane Doe", 42);
+    Person bob = new Person("Bob", 42);
+    System.out.println(jane);
+    System.out.println(bob);
+  }
+}

src/test/java/com/android/tools/r8/desugar/records/RecordShrinkFieldTest.java

diff --git a/src/test/java/com/android/tools/r8/desugar/records/RecordShrinkFieldTest.java b/src/test/java/com/android/tools/r8/desugar/records/RecordShrinkFieldTest.java
new file mode 100644
index 0000000..d46e947
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/desugar/records/RecordShrinkFieldTest.java
@@ -0,0 +1,97 @@
+// 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.desugar.records;
+
+import static org.junit.Assert.assertEquals;
+
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.utils.InternalOptions.TestingOptions;
+import com.android.tools.r8.utils.StringUtils;
+import com.android.tools.r8.utils.codeinspector.ClassSubject;
+import com.android.tools.r8.utils.codeinspector.CodeInspector;
+import java.nio.file.Path;
+import java.util.List;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+
+@RunWith(Parameterized.class)
+public class RecordShrinkFieldTest extends TestBase {
+
+  private static final String RECORD_NAME = "RecordShrinkField";
+  private static final byte[][] PROGRAM_DATA = RecordTestUtils.getProgramData(RECORD_NAME);
+  private static final String MAIN_TYPE = RecordTestUtils.getMainType(RECORD_NAME);
+  private static final String EXPECTED_RESULT =
+      StringUtils.lines("%s[name=Jane Doe, age=42, unused=-1]", "%s[name=Bob, age=42, unused=-1]");
+  private static final String EXPECTED_RESULT_D8 =
+      String.format(EXPECTED_RESULT, "Person", "Person");
+  private static final String EXPECTED_RESULT_R8 = String.format(EXPECTED_RESULT, "a", "a");
+
+  private final TestParameters parameters;
+
+  public RecordShrinkFieldTest(TestParameters parameters) {
+    this.parameters = parameters;
+  }
+
+  @Parameterized.Parameters(name = "{0}")
+  public static List<Object[]> data() {
+    return buildParameters(
+        getTestParameters().withDexRuntimes().withAllApiLevelsAlsoForCf().build());
+  }
+
+  @Test
+  public void testD8() throws Exception {
+    testForD8(parameters.getBackend())
+        .addProgramClassFileData(PROGRAM_DATA)
+        .setMinApi(parameters.getApiLevel())
+        .addOptionsModification(TestingOptions::allowExperimentClassFileVersion)
+        .compile()
+        .run(parameters.getRuntime(), MAIN_TYPE)
+        .assertSuccessWithOutput(EXPECTED_RESULT_D8);
+  }
+
+  @Test
+  public void testR8() throws Exception {
+    testForR8(parameters.getBackend())
+        .addProgramClassFileData(PROGRAM_DATA)
+        .setMinApi(parameters.getApiLevel())
+        .addKeepMainRule(MAIN_TYPE)
+        .addOptionsModification(TestingOptions::allowExperimentClassFileVersion)
+        .compile()
+        .inspect(this::assertSingleField)
+        .run(parameters.getRuntime(), MAIN_TYPE)
+        .assertSuccessWithOutput(EXPECTED_RESULT_R8);
+  }
+
+  @Test
+  public void testR8CfThenDex() throws Exception {
+    Path desugared =
+        testForR8(Backend.CF)
+            .addProgramClassFileData(PROGRAM_DATA)
+            .setMinApi(parameters.getApiLevel())
+            .addKeepMainRule(MAIN_TYPE)
+            .addLibraryFiles(RecordTestUtils.getJdk15LibraryFiles(temp))
+            .addOptionsModification(TestingOptions::allowExperimentClassFileVersion)
+            .compile()
+            .writeToZip();
+    testForR8(parameters.getBackend())
+        .addProgramFiles(desugared)
+        .setMinApi(parameters.getApiLevel())
+        .addKeepMainRule(MAIN_TYPE)
+        .addOptionsModification(TestingOptions::allowExperimentClassFileVersion)
+        .compile()
+        .inspect(this::assertSingleField)
+        .run(parameters.getRuntime(), MAIN_TYPE)
+        .assertSuccessWithOutput(EXPECTED_RESULT_R8);
+  }
+
+  private void assertSingleField(CodeInspector inspector) {
+    ClassSubject recordClass = inspector.clazz("records.a");
+    assertEquals(1, recordClass.allInstanceFields().size());
+    assertEquals(
+        "java.lang.String", recordClass.allInstanceFields().get(0).getField().type().toString());
+  }
+}