diff --git a/PREUPLOAD.cfg b/PREUPLOAD.cfg
index e781861..47f12b8 100644
--- a/PREUPLOAD.cfg
+++ b/PREUPLOAD.cfg
@@ -1,3 +1,10 @@
+[Builtin Hooks]
+clang_format = true
+
+[Builtin Hooks Options]
+clang_format = --commit ${PREUPLOAD_COMMIT} --style file --extensions c,h,cc,cpp
+               tests/tests/binder_ndk
+
 [Hook Scripts]
 checkstyle_hook = ${REPO_ROOT}/prebuilts/checkstyle/checkstyle.py --sha ${PREUPLOAD_COMMIT}
                   -fw apps/CtsVerifier/src/com/android/cts/verifier/usb/
diff --git a/tests/tests/binder_ndk/libbinder_ndk_test/.clang-format b/tests/tests/binder_ndk/libbinder_ndk_test/.clang-format
new file mode 100644
index 0000000..42714cd
--- /dev/null
+++ b/tests/tests/binder_ndk/libbinder_ndk_test/.clang-format
@@ -0,0 +1,7 @@
+BasedOnStyle: Google
+ColumnLimit: 100
+IndentWidth: 2
+PointerAlignment: Left
+AllowShortFunctionsOnASingleLine: Inline
+PointerAlignment: Left
+UseTab: Never
diff --git a/tests/tests/binder_ndk/libbinder_ndk_test/api/1/test_package/ITest.aidl b/tests/tests/binder_ndk/libbinder_ndk_test/api/1/test_package/ITest.aidl
index c212607..9a07405 100644
--- a/tests/tests/binder_ndk/libbinder_ndk_test/api/1/test_package/ITest.aidl
+++ b/tests/tests/binder_ndk/libbinder_ndk_test/api/1/test_package/ITest.aidl
@@ -33,6 +33,7 @@
   float[] RepeatFloatArray(in float[] input, out float[] repeated);
   double[] RepeatDoubleArray(in double[] input, out double[] repeated);
   String[] RepeatStringArray(in String[] input, out String[] repeated);
+  RegularPolygon[] RepeatRegularPolygonArray(in RegularPolygon[] input, out RegularPolygon[] repeated);
   @nullable boolean[] RepeatNullableBooleanArray(in @nullable boolean[] input);
   @nullable byte[] RepeatNullableByteArray(in @nullable byte[] input);
   @nullable char[] RepeatNullableCharArray(in @nullable char[] input);
diff --git a/tests/tests/binder_ndk/libbinder_ndk_test/itest_impl.h b/tests/tests/binder_ndk/libbinder_ndk_test/itest_impl.h
index b780f49..228759d 100644
--- a/tests/tests/binder_ndk/libbinder_ndk_test/itest_impl.h
+++ b/tests/tests/binder_ndk/libbinder_ndk_test/itest_impl.h
@@ -232,6 +232,13 @@
     *_aidl_return = in_value;
     return ::ndk::ScopedAStatus(AStatus_newOk());
   }
+  ::ndk::ScopedAStatus RepeatRegularPolygonArray(
+      const std::vector<RegularPolygon>& in_value, std::vector<RegularPolygon>* out_repeated,
+      std::vector<RegularPolygon>* _aidl_return) override {
+    *out_repeated = in_value;
+    *_aidl_return = in_value;
+    return ::ndk::ScopedAStatus(AStatus_newOk());
+  }
   ::ndk::ScopedAStatus RepeatNullableBooleanArray(
       const std::optional<std::vector<bool>>& in_value,
       std::optional<std::vector<bool>>* _aidl_return) override {
diff --git a/tests/tests/binder_ndk/libbinder_ndk_test/test_native_aidl_client.cpp b/tests/tests/binder_ndk/libbinder_ndk_test/test_native_aidl_client.cpp
index 3491f69..5a24284 100644
--- a/tests/tests/binder_ndk/libbinder_ndk_test/test_native_aidl_client.cpp
+++ b/tests/tests/binder_ndk/libbinder_ndk_test/test_native_aidl_client.cpp
@@ -316,6 +316,22 @@
 using RepeatMethod = ScopedAStatus (ITest::*)(const std::vector<T>&,
                                               std::vector<T>*, std::vector<T>*);
 
+namespace aidl {
+namespace test_package {
+inline bool operator==(const RegularPolygon& lhs, const RegularPolygon& rhs) {
+  return lhs.name == rhs.name && lhs.numSides == rhs.numSides && lhs.sideLength == rhs.sideLength;
+}
+inline bool operator==(const std::vector<RegularPolygon>& lhs,
+                       const std::vector<RegularPolygon>& rhs) {
+  if (lhs.size() != rhs.size()) return false;
+  for (size_t i = 0; i < lhs.size(); i++) {
+    if (!(lhs[i] == rhs[i])) return false;
+  }
+  return true;
+}
+}  // namespace test_package
+}  // namespace aidl
+
 template <typename T>
 void testRepeat(const std::shared_ptr<ITest>& i, RepeatMethod<T> repeatMethod,
                 std::vector<std::vector<T>> tests) {
@@ -379,6 +395,12 @@
                               {"asdf"},
                               {"", "aoeu", "lol", "brb"},
                           });
+  testRepeat<RegularPolygon>(iface, &ITest::RepeatRegularPolygonArray,
+                             {
+                                 {},
+                                 {{"hexagon", 6, 2.0f}},
+                                 {{"hexagon", 6, 2.0f}, {"square", 4, 7.0f}, {"pentagon", 5, 4.2f}},
+                             });
 }
 
 template <typename T>
@@ -493,9 +515,9 @@
 }
 
 class DefaultImpl : public ::aidl::test_package::ITestDefault {
-public:
+ public:
   ::ndk::ScopedAStatus NewMethodThatReturns10(int32_t* _aidl_return) override {
-    *_aidl_return = 100; // default impl returns different value
+    *_aidl_return = 100;  // default impl returns different value
     return ::ndk::ScopedAStatus(AStatus_newOk());
   }
 };
@@ -567,9 +589,7 @@
 }
 
 INSTANTIATE_TEST_CASE_P(LocalNative, NdkBinderTest_Aidl,
-                        ::testing::Values(Params{getLocalService(),
-                                                 false /*shouldBeRemote*/,
-                                                 "CPP",
+                        ::testing::Values(Params{getLocalService(), false /*shouldBeRemote*/, "CPP",
                                                  false /*shouldBeOld*/}));
 INSTANTIATE_TEST_CASE_P(
     LocalNativeFromJava, NdkBinderTest_Aidl,
@@ -577,9 +597,9 @@
         getNdkBinderTestJavaService("getLocalNativeService"),
         false /*shouldBeRemote*/, "CPP", false /*shouldBeOld*/}));
 INSTANTIATE_TEST_CASE_P(LocalJava, NdkBinderTest_Aidl,
-                        ::testing::Values(Params{
-                            getNdkBinderTestJavaService("getLocalJavaService"),
-                            false /*shouldBeRemote*/, "JAVA", false /*shouldBeOld*/}));
+                        ::testing::Values(Params{getNdkBinderTestJavaService("getLocalJavaService"),
+                                                 false /*shouldBeRemote*/, "JAVA",
+                                                 false /*shouldBeOld*/}));
 INSTANTIATE_TEST_CASE_P(
     RemoteNative, NdkBinderTest_Aidl,
     ::testing::Values(Params{
diff --git a/tests/tests/binder_ndk/libbinder_ndk_test/test_package/ITest.aidl b/tests/tests/binder_ndk/libbinder_ndk_test/test_package/ITest.aidl
index 7329271..1061b94 100644
--- a/tests/tests/binder_ndk/libbinder_ndk_test/test_package/ITest.aidl
+++ b/tests/tests/binder_ndk/libbinder_ndk_test/test_package/ITest.aidl
@@ -78,6 +78,7 @@
     float[] RepeatFloatArray(in float[] input, out float[] repeated);
     double[] RepeatDoubleArray(in double[] input, out double[] repeated);
     String[] RepeatStringArray(in String[] input, out String[] repeated);
+    RegularPolygon[] RepeatRegularPolygonArray(in RegularPolygon[] input, out RegularPolygon[] repeated);
 
     // Nullable Arrays
     @nullable boolean[] RepeatNullableBooleanArray(in @nullable boolean[] input);
diff --git a/tests/tests/binder_ndk/libbinder_ndk_test/test_parcel.cpp b/tests/tests/binder_ndk/libbinder_ndk_test/test_parcel.cpp
index 87279a5..80c7313 100644
--- a/tests/tests/binder_ndk/libbinder_ndk_test/test_parcel.cpp
+++ b/tests/tests/binder_ndk/libbinder_ndk_test/test_parcel.cpp
@@ -211,7 +211,7 @@
     // every element of the vector is a prefix of this string
     const std::string& element;
     // this is the number of characters of the string to write, < element.size()
-    size_t elementLen;
+    int32_t elementLen;
 
     binder_status_t writeToParcel(AParcel* p, size_t length) const {
       return AParcel_writeStringArray(p, static_cast<const void*>(this), length,
@@ -219,8 +219,7 @@
     }
 
    private:
-    static const char* ElementGetter(const void* vectorData, size_t /*index*/,
-                                     size_t* outLength) {
+    static const char* ElementGetter(const void* vectorData, size_t /*index*/, int32_t* outLength) {
       const PartialStringCycle* vector =
           static_cast<const PartialStringCycle*>(vectorData);
 
@@ -236,7 +235,8 @@
     const std::vector<std::string> expectedVector = {expectedString,
                                                      expectedString};
 
-    const PartialStringCycle writeVector{.element = kTestcase, .elementLen = i};
+    const PartialStringCycle writeVector{.element = kTestcase,
+                                         .elementLen = static_cast<int32_t>(i)};
 
     AIBinder* binder = SampleData::newBinder(
         [&](transaction_code_t, const AParcel* in, AParcel* /*out*/) {
diff --git a/tests/tests/binder_ndk/src/android/binder/cts/JavaClientTest.java b/tests/tests/binder_ndk/src/android/binder/cts/JavaClientTest.java
index 4552c0e..ce71d32 100644
--- a/tests/tests/binder_ndk/src/android/binder/cts/JavaClientTest.java
+++ b/tests/tests/binder_ndk/src/android/binder/cts/JavaClientTest.java
@@ -217,6 +217,18 @@
         assertEquals("foo", mInterface.RepeatNullableString("foo"));
     }
 
+    public void assertPolygonEquals(RegularPolygon lhs, RegularPolygon rhs) {
+        assertEquals(lhs.name, rhs.name);
+        assertEquals(lhs.numSides, rhs.numSides);
+        assertEquals(lhs.sideLength, rhs.sideLength, 0.0f);
+    }
+    public void assertPolygonEquals(RegularPolygon[] lhs, RegularPolygon[] rhs) {
+        assertEquals(lhs.length, rhs.length);
+        for (int i = 0; i < lhs.length; i++) {
+            assertPolygonEquals(lhs[i], rhs[i]);
+        }
+    }
+
     @Test
     public void testRepeatPolygon() throws RemoteException {
         RegularPolygon polygon = new RegularPolygon();
@@ -226,9 +238,7 @@
 
         RegularPolygon result = mInterface.RepeatPolygon(polygon);
 
-        assertEquals(polygon.name, result.name);
-        assertEquals(polygon.numSides, result.numSides);
-        assertEquals(polygon.sideLength, result.sideLength, 0.0f);
+        assertPolygonEquals(polygon, result);
     }
 
     @Test
@@ -312,6 +322,20 @@
             Assert.assertArrayEquals(value, out1);
             Assert.assertArrayEquals(value, out2);
         }
+        {
+
+            RegularPolygon septagon = new RegularPolygon();
+            septagon.name = "septagon";
+            septagon.numSides = 7;
+            septagon.sideLength = 1.0f;
+
+            RegularPolygon[] value = {septagon, new RegularPolygon(), new RegularPolygon()};
+            RegularPolygon[] out1 = new RegularPolygon[value.length];
+            RegularPolygon[] out2 = mInterface.RepeatRegularPolygonArray(value, out1);
+
+            assertPolygonEquals(value, out1);
+            assertPolygonEquals(value, out2);
+        }
     }
 
     @Test
diff --git a/tests/tests/binder_ndk/src/android/binder/cts/TestImpl.java b/tests/tests/binder_ndk/src/android/binder/cts/TestImpl.java
index 0cd785e..168ee9e 100644
--- a/tests/tests/binder_ndk/src/android/binder/cts/TestImpl.java
+++ b/tests/tests/binder_ndk/src/android/binder/cts/TestImpl.java
@@ -222,6 +222,12 @@
   }
 
   @Override
+  public RegularPolygon[] RepeatRegularPolygonArray(RegularPolygon[] in_value, RegularPolygon[] repeated) {
+    System.arraycopy(in_value, 0, repeated, 0, in_value.length);
+    return in_value;
+  }
+
+  @Override
   public boolean[] RepeatNullableBooleanArray(boolean[] in_value) {
     return in_value;
   }