diff --git a/javatests/com/google/gerrit/plugins/codeowners/backend/AbstractAutoValueTest.java b/javatests/com/google/gerrit/plugins/codeowners/backend/AbstractAutoValueTest.java
new file mode 100644
index 0000000..1a3c163
--- /dev/null
+++ b/javatests/com/google/gerrit/plugins/codeowners/backend/AbstractAutoValueTest.java
@@ -0,0 +1,35 @@
+// Copyright (C) 2021 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.plugins.codeowners.backend;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import com.google.gerrit.plugins.codeowners.acceptance.AbstractCodeOwnersTest;
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+
+/** Base class for tests of AutoValue classes. */
+abstract class AbstractAutoValueTest extends AbstractCodeOwnersTest {
+  protected <T> void assertThatToStringIncludesAllData(
+      T autoValueObjectToTest, Class<T> autoValueClass) throws Exception {
+    for (Method method : autoValueClass.getDeclaredMethods()) {
+      if (Modifier.isAbstract(method.getModifiers())) {
+        Object result = method.invoke(autoValueObjectToTest);
+        assertThat(autoValueObjectToTest.toString())
+            .contains(String.format("%s=%s", method.getName(), result));
+      }
+    }
+  }
+}
diff --git a/javatests/com/google/gerrit/plugins/codeowners/backend/CodeOwnerResolverResultTest.java b/javatests/com/google/gerrit/plugins/codeowners/backend/CodeOwnerResolverResultTest.java
new file mode 100644
index 0000000..d64f5bf
--- /dev/null
+++ b/javatests/com/google/gerrit/plugins/codeowners/backend/CodeOwnerResolverResultTest.java
@@ -0,0 +1,34 @@
+// Copyright (C) 2021 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.plugins.codeowners.backend;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
+import org.junit.Test;
+
+/** Tests for {@link CodeOwnerResolverResult}. */
+public class CodeOwnerResolverResultTest extends AbstractAutoValueTest {
+  @Test
+  public void toStringIncludesAllData() throws Exception {
+    CodeOwnerResolverResult codeOwnerResolverResult =
+        CodeOwnerResolverResult.create(
+            ImmutableSet.of(CodeOwner.create(admin.id())),
+            /* ownedByAllUsers= */ false,
+            /* hasUnresolvedCodeOwners= */ false,
+            /* hasUnresolvedImports= */ false,
+            ImmutableList.of("test message"));
+    assertThatToStringIncludesAllData(codeOwnerResolverResult, CodeOwnerResolverResult.class);
+  }
+}
diff --git a/javatests/com/google/gerrit/plugins/codeowners/backend/PathCodeOwnersResultTest.java b/javatests/com/google/gerrit/plugins/codeowners/backend/PathCodeOwnersResultTest.java
new file mode 100644
index 0000000..d270fdc
--- /dev/null
+++ b/javatests/com/google/gerrit/plugins/codeowners/backend/PathCodeOwnersResultTest.java
@@ -0,0 +1,46 @@
+// Copyright (C) 2021 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.plugins.codeowners.backend;
+
+import com.google.common.collect.ImmutableList;
+import java.nio.file.Paths;
+import org.eclipse.jgit.lib.ObjectId;
+import org.junit.Test;
+
+/** Tests for {@link PathCodeOwnersResult}. */
+public class PathCodeOwnersResultTest extends AbstractAutoValueTest {
+  private static final ObjectId TEST_REVISION =
+      ObjectId.fromString("deadbeefdeadbeefdeadbeefdeadbeefdeadbeef");
+
+  @Test
+  public void toStringIncludesAllData() throws Exception {
+    CodeOwnerConfig.Key codeOwnerConfigKey = CodeOwnerConfig.Key.create(project, "master", "/");
+    CodeOwnerConfigReference codeOwnerConfigReference =
+        CodeOwnerConfigReference.create(CodeOwnerConfigImportMode.ALL, "/bar/OWNERS");
+    PathCodeOwnersResult pathCodeOwnersResult =
+        PathCodeOwnersResult.create(
+            Paths.get("/foo/bar/baz.md"),
+            CodeOwnerConfig.builder(codeOwnerConfigKey, TEST_REVISION)
+                .addImport(codeOwnerConfigReference)
+                .build(),
+            ImmutableList.of(
+                UnresolvedImport.create(
+                    codeOwnerConfigKey,
+                    CodeOwnerConfig.Key.create(project, "master", "/bar/"),
+                    codeOwnerConfigReference,
+                    "test message")));
+    assertThatToStringIncludesAllData(pathCodeOwnersResult, PathCodeOwnersResult.class);
+  }
+}
diff --git a/javatests/com/google/gerrit/plugins/codeowners/backend/UnresolvedImportTest.java b/javatests/com/google/gerrit/plugins/codeowners/backend/UnresolvedImportTest.java
new file mode 100644
index 0000000..ce0494f
--- /dev/null
+++ b/javatests/com/google/gerrit/plugins/codeowners/backend/UnresolvedImportTest.java
@@ -0,0 +1,31 @@
+// Copyright (C) 2021 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.plugins.codeowners.backend;
+
+import org.junit.Test;
+
+/** Tests for {@link UnresolvedImport}. */
+public class UnresolvedImportTest extends AbstractAutoValueTest {
+  @Test
+  public void toStringIncludesAllData() throws Exception {
+    UnresolvedImport unresolvedImport =
+        UnresolvedImport.create(
+            CodeOwnerConfig.Key.create(project, "master", "/"),
+            CodeOwnerConfig.Key.create(project, "master", "/bar/"),
+            CodeOwnerConfigReference.create(CodeOwnerConfigImportMode.ALL, "/bar/OWNERS"),
+            "test message");
+    assertThatToStringIncludesAllData(unresolvedImport, UnresolvedImport.class);
+  }
+}