Add ArrayBuffer sample methods to TurboModule examples (facebook#56690)

christophpurrer · meta-codesync[bot] · commit 2226f51a0dcf · 2026-05-06T21:59:20.000-07:00
Summary: Pull Request resolved: facebook#56690 ## Changelog: [General] [Added] - Add ArrayBuffer sample methods to TurboModule examples react-native-community/discussions-and-proposals#947 Add `getArrayBuffer` method to NativeCxxModuleExample and NativeSampleTurboModule specs to demonstrate and validate ArrayBuffer support across all platforms. - **JS Specs:** Added `getArrayBuffer: (arg: ArrayBuffer) => ArrayBuffer` to both NativeCxxModuleExample.js and NativeSampleTurboModule.js - **C++:** Implemented in NativeCxxModuleExample.cpp using `OwnedMutableBuffer` to copy and return the ArrayBuffer - **Java/Kotlin:** Implemented in SampleTurboModule.kt with `ByteBuffer` param/return - **ObjC:** Implemented in RCTSampleTurboModule.mm (iOS + macOS) with `NSData *` param/return Reviewed By: javache Differential Revision: D95652569
diff --git a/packages/react-native/React/Base/RCTConvert.mm b/packages/react-native/React/Base/RCTConvert.mm
@@ -60,7 +60,24 @@ +(type *)type : (id)json       \
 RCT_JSON_CONVERTER(NSNumber)
 
 RCT_CUSTOM_CONVERTER(NSSet *, NSSet, [NSSet setWithArray:json])
-RCT_CUSTOM_CONVERTER(NSData *, NSData, [json dataUsingEncoding:NSUTF8StringEncoding])
+
++ (NSData *)NSData:(id)json RCT_DYNAMIC
+{
+  // Return NSData as-is (e.g., when bridging ArrayBuffer from JS).
+  if ([json isKindOfClass:[NSData class]]) {
+    return json;
+  }
+  if (!RCT_DEBUG) {
+    return [json dataUsingEncoding:NSUTF8StringEncoding];
+  } else {
+    @try {
+      return [json dataUsingEncoding:NSUTF8StringEncoding];
+    } @catch (__unused NSException *e) {
+      RCTLogConvertError(json, @"NSData");
+      return nil;
+    }
+  }
+}
 
 + (NSIndexSet *)NSIndexSet:(id)json
 {
diff --git a/packages/react-native/ReactCommon/react/nativemodule/samples/platform/android/NativeSampleTurboModuleSpec.java b/packages/react-native/ReactCommon/react/nativemodule/samples/platform/android/NativeSampleTurboModuleSpec.java
@@ -21,6 +21,7 @@
 import com.facebook.react.bridge.WritableMap;
 import com.facebook.react.common.build.ReactBuildConfig;
 import com.facebook.react.turbomodule.core.interfaces.TurboModule;
+import java.nio.ByteBuffer;
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Map;
@@ -165,4 +166,10 @@ public void promiseAssert(Promise promise) {}
   @ReactMethod
   @DoNotStrip
   public void getImageUrl(Promise promise) {}
+
+  @ReactMethod(isBlockingSynchronousMethod = true)
+  @DoNotStrip
+  public ByteBuffer getArrayBuffer(ByteBuffer arg) {
+    return null;
+  }
 }
diff --git a/packages/react-native/ReactCommon/react/nativemodule/samples/platform/android/ReactCommon/SampleTurboModuleSpec.cpp b/packages/react-native/ReactCommon/react/nativemodule/samples/platform/android/ReactCommon/SampleTurboModuleSpec.cpp
@@ -328,6 +328,24 @@ __hostFunction_NativeSampleTurboModuleSpecJSI_getImageUrl(
           cachedMethodId);
 }
 
+static facebook::jsi::Value
+__hostFunction_NativeSampleTurboModuleSpecJSI_getArrayBuffer(
+    facebook::jsi::Runtime& rt,
+    TurboModule& turboModule,
+    const facebook::jsi::Value* args,
+    size_t count) {
+  static jmethodID cachedMethodId = nullptr;
+  return static_cast<JavaTurboModule&>(turboModule)
+      .invokeJavaMethod(
+          rt,
+          ArrayBufferKind,
+          "getArrayBuffer",
+          "(Ljava/nio/ByteBuffer;)Ljava/nio/ByteBuffer;",
+          args,
+          count,
+          cachedMethodId);
+}
+
 NativeSampleTurboModuleSpecJSI::NativeSampleTurboModuleSpecJSI(
     const JavaTurboModule::InitParams& params)
     : JavaTurboModule(params) {
@@ -393,6 +411,9 @@ NativeSampleTurboModuleSpecJSI::NativeSampleTurboModuleSpecJSI(
   methodMap_["getImageUrl"] = MethodMetadata{
       .argCount = 0,
       .invoker = __hostFunction_NativeSampleTurboModuleSpecJSI_getImageUrl};
+  methodMap_["getArrayBuffer"] = MethodMetadata{
+      .argCount = 1,
+      .invoker = __hostFunction_NativeSampleTurboModuleSpecJSI_getArrayBuffer};
   eventEmitterMap_["onPress"] =
       std::make_shared<AsyncEventEmitter<folly::dynamic>>();
   eventEmitterMap_["onClick"] =
diff --git a/packages/react-native/ReactCommon/react/nativemodule/samples/platform/android/SampleTurboModule.kt b/packages/react-native/ReactCommon/react/nativemodule/samples/platform/android/SampleTurboModule.kt
@@ -27,6 +27,7 @@ import com.facebook.react.bridge.WritableNativeMap
 import com.facebook.react.module.annotations.ReactModule
 import com.facebook.react.turbomodule.core.interfaces.BindingsInstallerHolder
 import com.facebook.react.turbomodule.core.interfaces.TurboModuleWithJSIBindings
+import java.nio.ByteBuffer
 import java.util.UUID
 
 @DoNotStrip
@@ -225,6 +226,20 @@ public class SampleTurboModule(private val context: ReactApplicationContext) :
     assert(false) { "Intentional assert from JVM promiseAssert" }
   }
 
+  @DoNotStrip
+  @Suppress("unused")
+  override fun getArrayBuffer(arg: ByteBuffer): ByteBuffer {
+    // Reverse the bytes in place, mutating the JS-owned ByteBuffer directly.
+    val length = arg.capacity()
+    for (i in 0 until length / 2) {
+      val tmp = arg.get(i)
+      arg.put(i, arg.get(length - 1 - i))
+      arg.put(length - 1 - i, tmp)
+    }
+    log("getArrayBuffer", arg, arg)
+    return arg
+  }
+
   @DoNotStrip
   @Suppress("unused")
   override fun getImageUrl(promise: Promise) {
diff --git a/packages/react-native/ReactCommon/react/nativemodule/samples/platform/ios/ReactCommon/RCTNativeSampleTurboModuleSpec.h b/packages/react-native/ReactCommon/react/nativemodule/samples/platform/ios/ReactCommon/RCTNativeSampleTurboModuleSpec.h
@@ -104,6 +104,7 @@ inline JS::NativeSampleTurboModule::Constants::Builder::Builder(Constants i)
 - (NSDictionary *)getObjectAssert:(NSDictionary *)arg;
 - (void)promiseAssert:(RCTPromiseResolveBlock)resolve reject:(RCTPromiseRejectBlock)reject;
 - (void)getImageUrl:(RCTPromiseResolveBlock)resolve reject:(RCTPromiseRejectBlock)reject;
+- (NSMutableData *)getArrayBuffer:(NSMutableData *)arg;
 - (facebook::react::ModuleConstants<JS::NativeSampleTurboModule::Constants>)constantsToExport;
 - (facebook::react::ModuleConstants<JS::NativeSampleTurboModule::Constants>)getConstants;
 
diff --git a/packages/react-native/ReactCommon/react/nativemodule/samples/platform/ios/ReactCommon/RCTNativeSampleTurboModuleSpec.mm b/packages/react-native/ReactCommon/react/nativemodule/samples/platform/ios/ReactCommon/RCTNativeSampleTurboModuleSpec.mm
@@ -224,6 +224,16 @@ - (void)setEventEmitterCallback:(EventEmitterCallbackWrapper *)eventEmitterCallb
       .invokeObjCMethod(rt, PromiseKind, "getImageUrl", @selector(getImageUrl:reject:), args, count);
 }
 
+static facebook::jsi::Value __hostFunction_NativeSampleTurboModuleSpecJSI_getArrayBuffer(
+    facebook::jsi::Runtime &rt,
+    TurboModule &turboModule,
+    const facebook::jsi::Value *args,
+    size_t count)
+{
+  return static_cast<ObjCTurboModule &>(turboModule)
+      .invokeObjCMethod(rt, ArrayBufferKind, "getArrayBuffer", @selector(getArrayBuffer:), args, count);
+}
+
 static facebook::jsi::Value __hostFunction_NativeSampleTurboModuleSpecJSI_getConstants(
     facebook::jsi::Runtime &rt,
     TurboModule &turboModule,
@@ -277,6 +287,9 @@ - (void)setEventEmitterCallback:(EventEmitterCallbackWrapper *)eventEmitterCallb
 
   methodMap_["getImageUrl"] = MethodMetadata{0, __hostFunction_NativeSampleTurboModuleSpecJSI_getImageUrl};
 
+  methodMap_["getArrayBuffer"] =
+      MethodMetadata{.argCount = 1, .invoker = __hostFunction_NativeSampleTurboModuleSpecJSI_getArrayBuffer};
+
   methodMap_["getConstants"] = MethodMetadata{0, __hostFunction_NativeSampleTurboModuleSpecJSI_getConstants};
 
   eventEmitterMap_["onPress"] = std::make_shared<AsyncEventEmitter<id>>();
diff --git a/packages/react-native/ReactCommon/react/nativemodule/samples/platform/ios/ReactCommon/RCTSampleTurboModule.mm b/packages/react-native/ReactCommon/react/nativemodule/samples/platform/ios/ReactCommon/RCTSampleTurboModule.mm
@@ -13,6 +13,8 @@
 #import <React/RCTUtils.h>
 #import <ReactCommon/RCTTurboModuleWithJSIBindings.h>
 #import <UIKit/UIKit.h>
+#import <algorithm>
+#import <span>
 
 using namespace facebook::react;
 
@@ -210,6 +212,16 @@ - (void)installJSIBindingsWithRuntime:(facebook::jsi::Runtime &)runtime
   RCTAssert(false, @"Intentional assert from ObjC promiseAssert");
 }
 
+RCT_EXPORT_SYNCHRONOUS_TYPED_METHOD(NSMutableData *, getArrayBuffer : (NSMutableData *)arg)
+{
+  // Reverse the bytes in place. The NSMutableData is backed by JS-owned memory
+  // wrapped via [NSMutableData dataWithBytesNoCopy:freeWhenDone:NO] for sync
+  // calls, so the underlying buffer is mutable.
+  std::span<uint8_t> bytes(static_cast<uint8_t *>(arg.mutableBytes), arg.length);
+  std::reverse(bytes.begin(), bytes.end());
+  return arg;
+}
+
 @end
 
 Class _Nonnull RCTSampleTurboModuleCls(void)
diff --git a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeSampleTurboModule.js b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeSampleTurboModule.js
@@ -47,6 +47,7 @@ export interface Spec extends TurboModule {
   +getNumber: (arg: number) => number;
   +getString: (arg: string) => string;
   +getArray: (arg: Array<any>) => Array<any>;
+  +getArrayBuffer: (arg: ArrayBuffer) => ArrayBuffer;
   +getObject: (arg: Object) => Object;
   +getUnsafeObject: (arg: UnsafeObject) => UnsafeObject;
   +getRootTag: (arg: RootTag) => RootTag;
diff --git a/packages/rn-tester/NativeCxxModuleExample/NativeCxxModuleExample.cpp b/packages/rn-tester/NativeCxxModuleExample/NativeCxxModuleExample.cpp
@@ -6,7 +6,9 @@
  */
 
 #include "NativeCxxModuleExample.h"
+#include <react/bridging/ArrayBuffer.h>
 #include <react/debug/react_native_assert.h>
+#include <cstring>
 #include <iomanip>
 #include <ostream>
 #include <sstream>
@@ -265,4 +267,17 @@ AsyncPromise<> NativeCxxModuleExample::promiseAssert(jsi::Runtime& rt) {
   return promise;
 };
 
+jsi::ArrayBuffer NativeCxxModuleExample::getArrayBuffer(
+    jsi::Runtime& rt,
+    jsi::ArrayBuffer arg) {
+  // Reverse the bytes of the input ArrayBuffer in place, mutating the
+  // JS-owned memory directly.
+  auto* data = arg.data(rt);
+  auto size = arg.size(rt);
+  for (size_t i = 0; i < size / 2; ++i) {
+    std::swap(data[i], data[size - 1 - i]);
+  }
+  return arg;
+}
+
 } // namespace facebook::react
diff --git a/packages/rn-tester/NativeCxxModuleExample/NativeCxxModuleExample.h b/packages/rn-tester/NativeCxxModuleExample/NativeCxxModuleExample.h
@@ -182,6 +182,8 @@ class NativeCxxModuleExample : public NativeCxxModuleExampleCxxSpec<NativeCxxMod
 
   AsyncPromise<> promiseAssert(jsi::Runtime &rt);
 
+  jsi::ArrayBuffer getArrayBuffer(jsi::Runtime &rt, jsi::ArrayBuffer arg);
+
  private:
   std::optional<AsyncCallback<std::string>> valueCallback_;
 };
diff --git a/packages/rn-tester/NativeCxxModuleExample/NativeCxxModuleExample.js b/packages/rn-tester/NativeCxxModuleExample/NativeCxxModuleExample.js
@@ -82,6 +82,7 @@ export interface Spec extends TurboModule {
   +onSubmit: CodegenTypes.EventEmitter<ObjectStruct[]>;
   +onEvent: CodegenTypes.EventEmitter<EnumNone>;
   +getArray: (arg: Array<ObjectStruct | null>) => Array<ObjectStruct | null>;
+  +getArrayBuffer: (arg: ArrayBuffer) => ArrayBuffer;
   +getBool: (arg: boolean) => boolean;
   +getConstants: () => ConstantsStruct;
   +getCustomEnum: (arg: EnumInt) => EnumInt;
diff --git a/packages/rn-tester/NativeCxxModuleExample/tests/NativeCxxModuleExampleTests.cpp b/packages/rn-tester/NativeCxxModuleExample/tests/NativeCxxModuleExampleTests.cpp
@@ -8,6 +8,7 @@
 #include <NativeCxxModuleExample/NativeCxxModuleExample.h>
 #include <ReactCommon/TurboModuleTestFixture.h>
 #include <gtest/gtest.h>
+#include <cstring>
 #include <memory>
 #include <optional>
 #include <vector>
@@ -31,6 +32,28 @@ TEST_F(NativeCxxModuleExampleTests, GetArrayReturnsCorrectValues) {
   EXPECT_EQ(result[0]->b, "2");
 }
 
+TEST_F(NativeCxxModuleExampleTests, GetArrayBufferReturnsCorrectValues) {
+  // Create an ArrayBuffer with known data
+  std::vector<uint8_t> inputData = {1, 2, 3, 4, 5};
+  auto inputBuffer =
+      std::make_shared<SharedMutableBuffer>(inputData.data(), inputData.size());
+  jsi::ArrayBuffer arg(*runtime_, std::move(inputBuffer));
+
+  auto result = module_->getArrayBuffer(*runtime_, std::move(arg));
+  ASSERT_EQ(result.size(*runtime_), inputData.size());
+  EXPECT_EQ(
+      std::memcmp(result.data(*runtime_), inputData.data(), inputData.size()),
+      0);
+}
+
+TEST_F(NativeCxxModuleExampleTests, GetArrayBufferEmptyReturnsEmpty) {
+  auto inputBuffer = std::make_shared<SharedMutableBuffer>(nullptr, 0);
+  jsi::ArrayBuffer arg(*runtime_, std::move(inputBuffer));
+
+  auto result = module_->getArrayBuffer(*runtime_, std::move(arg));
+  EXPECT_EQ(result.size(*runtime_), 0);
+}
+
 TEST_F(NativeCxxModuleExampleTests, GetBoolReturnsCorrectValues) {
   EXPECT_FALSE(module_->getBool(*runtime_, false));
   EXPECT_TRUE(module_->getBool(*runtime_, true));
diff --git a/packages/rn-tester/js/examples/TurboModule/NativeCxxModuleExampleExample.js b/packages/rn-tester/js/examples/TurboModule/NativeCxxModuleExampleExample.js
@@ -40,6 +40,7 @@ type Examples =
   | 'callback'
   | 'callbackWithSubscription'
   | 'getArray'
+  | 'getArrayBuffer'
   | 'getBool'
   | 'getConstants'
   | 'getCustomEnum'
@@ -102,6 +103,19 @@ class NativeCxxModuleExampleExample extends React.Component<{}, State> {
         {a: 2, b: 'bar'},
         null,
       ]),
+    getArrayBuffer: () => {
+      const buffer = new ArrayBuffer(4);
+      const view = new Uint8Array(buffer);
+      view[0] = 1;
+      view[1] = 2;
+      view[2] = 3;
+      view[3] = 4;
+      const result = NativeCxxModuleExample?.getArrayBuffer(buffer);
+      if (result) {
+        return Array.from(new Uint8Array(result));
+      }
+      return null;
+    },
     getBool: () => NativeCxxModuleExample?.getBool(true),
     getConstants: () => NativeCxxModuleExample?.getConstants(),
     getCustomEnum: () => NativeCxxModuleExample?.getCustomEnum(EnumInt.IB),
diff --git a/packages/rn-tester/js/examples/TurboModule/SampleTurboModuleExample.js b/packages/rn-tester/js/examples/TurboModule/SampleTurboModuleExample.js
@@ -31,6 +31,7 @@ type State = {
 type Examples =
   | 'callback'
   | 'getArray'
+  | 'getArrayBuffer'
   | 'getBool'
   | 'getConstants'
   | 'getCustomEnum'
@@ -101,6 +102,22 @@ class SampleTurboModuleExample extends React.Component<{}, State> {
         {a: 2, b: 'bar'},
         null,
       ]),
+    getArrayBuffer: () => {
+      if (!NativeSampleTurboModule.getArrayBuffer) {
+        return null;
+      }
+      const buffer = new ArrayBuffer(4);
+      const view = new Uint8Array(buffer);
+      view[0] = 1;
+      view[1] = 2;
+      view[2] = 3;
+      view[3] = 4;
+      const result = NativeSampleTurboModule.getArrayBuffer(buffer);
+      if (result) {
+        return Array.from(new Uint8Array(result));
+      }
+      return null;
+    },
     getObject: () =>
       NativeSampleTurboModule.getObject({a: 1, b: 'foo', c: null}),
     getUnsafeObject: () =>
