diff --git a/BUILD.bazel b/BUILD.bazel
index b5ac9a7d74..37fd12d8b5 100644
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -52,9 +52,13 @@ java_binary(
     name = "junit_runner",
     srcs = [
         "//src/test/java/com/google/api/generator/gapic/dummy:dummy_files",
+        "//src/test/java/com/google/api/generator/engine:engine_files",
         "//src/test/java/com/google/api/generator/test/framework:framework_files",
     ],
-    data = ["//src/test/java/com/google/api/generator/gapic/dummy/goldens:goldens_files"],
+    data = [
+        "//src/test/java/com/google/api/generator/gapic/dummy/goldens:goldens_files",
+        "//src/test/java/com/google/api/generator/engine/goldens:goldens_files",
+        ],
     jvm_flags = ["-Xmx512m"],
     main_class = "com.google.api.generator.test.framework.SingleJUnitTestRunner",
     visibility = ["//visibility:public"],
@@ -62,6 +66,9 @@ java_binary(
         "//src/main/java/com/google/api/generator/engine/ast",
         "//src/main/java/com/google/api/generator/engine/writer",
         "//src/test/java/com/google/api/generator/test/framework",
+        "//src/main/java/com/google/api/generator/engine/lexicon",
+        "@com_google_guava_guava//:com_google_guava_guava",
+        "@com_google_truth_truth//jar",
         "@io_github_java_diff_utils//jar",
         "@junit_junit//jar",
         "@org_hamcrest_hamcrest_core//jar",
diff --git a/src/test/java/com/google/api/generator/engine/BUILD.bazel b/src/test/java/com/google/api/generator/engine/BUILD.bazel
index 54b08dfd36..90bd694347 100644
--- a/src/test/java/com/google/api/generator/engine/BUILD.bazel
+++ b/src/test/java/com/google/api/generator/engine/BUILD.bazel
@@ -1,3 +1,5 @@
+load("//:rules_bazel/java/java_diff_test.bzl", "updated_golden")
+
 package(default_visibility = ["//visibility:public"])
 
 filegroup(
@@ -25,3 +27,15 @@ TESTS = [
         "@junit_junit//jar",
     ],
 ) for test_name in TESTS]
+
+TEST_CLASS_NAME = "com.google.api.generator.engine.JavaCodeGeneratorTest"
+
+# Run `bazel run src/test/java/com/google/api/generator/engine:JavaCodeGeneratorTest_update`
+# to update goldens as expected generated code.
+updated_golden(
+    name = "JavaCodeGeneratorTest_update",
+    srcs = [
+        ":engine_files",
+    ],
+    test_class_name = TEST_CLASS_NAME,
+)
diff --git a/src/test/java/com/google/api/generator/engine/JavaCodeGeneratorTest.java b/src/test/java/com/google/api/generator/engine/JavaCodeGeneratorTest.java
index 3383fb94b0..8ed58c13cb 100644
--- a/src/test/java/com/google/api/generator/engine/JavaCodeGeneratorTest.java
+++ b/src/test/java/com/google/api/generator/engine/JavaCodeGeneratorTest.java
@@ -50,6 +50,7 @@
 import com.google.api.generator.engine.ast.WhileStatement;
 import com.google.api.generator.engine.writer.JavaWriterVisitor;
 import com.google.api.generator.test.framework.Assert;
+import com.google.api.generator.test.framework.Utils;
 import java.io.FileWriter;
 import java.io.IOException;
 import java.nio.file.Path;
@@ -172,6 +173,8 @@ public void validJavaClass() {
             .build();
     JavaWriterVisitor javaWriterVisitor = new JavaWriterVisitor();
     libraryServiceStubClass.accept(javaWriterVisitor);
+    Utils.saveCodegenToFile(
+        this.getClass(), "JavaCodeGeneratorTest.golden", javaWriterVisitor.write());
     Path goldenFilePath = Paths.get(GOLDENFILES_DIRECTORY, "JavaCodeGeneratorTest.golden");
     Assert.assertCodeEquals(goldenFilePath, javaWriterVisitor.write());
   }