xplat/js/react-native-github/packages/react-native/ReactAndroid/src/main/jni/react/reactnativeblob/BlobCollector.cpp

packages/react-native/ReactAndroid/src/main/jni/react/reactnativeblob/test/BlobCollectorTest.cpp

@@ -0,0 +1,151 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include "BlobCollector.h"
+
+#include <fbjni/fbjni.h>
+#include <gtest/gtest.h>
+
+#include <array>
+#include <memory>
+#include <string>
+
+namespace facebook::react {
+namespace {
+
+class JContext : public jni::JavaClass<JContext> {
+ public:
+  static constexpr auto kJavaDescriptor = "Landroid/content/Context;";
+};
+
+class JInstrumentation : public jni::JavaClass<JInstrumentation> {
+ public:
+  static constexpr auto kJavaDescriptor = "Landroid/app/Instrumentation;";
+
+  jni::local_ref<JContext> getTargetContext() {
+    static const auto method =
+        javaClassStatic()->getMethod<JContext::javaobject()>(
+            "getTargetContext");
+    return method(self());
+  }
+};
+
+class JInstrumentationRegistry
+    : public jni::JavaClass<JInstrumentationRegistry> {
+ public:
+  static constexpr auto kJavaDescriptor =
+      "Landroidx/test/platform/app/InstrumentationRegistry;";
+
+  static jni::local_ref<JInstrumentation> getInstrumentation() {
+    static const auto method =
+        javaClassStatic()->getStaticMethod<JInstrumentation::javaobject()>(
+            "getInstrumentation");
+    return method(javaClassStatic());
+  }
+};
+
+class JReactApplicationContext
+    : public jni::JavaClass<JReactApplicationContext> {
+ public:
+  static constexpr auto kJavaDescriptor =
+      "Lcom/facebook/react/bridge/ReactApplicationContext;";
+};
+
+class JBridgeReactContext
+    : public jni::JavaClass<JBridgeReactContext, JReactApplicationContext> {
+ public:
+  static constexpr auto kJavaDescriptor =
+      "Lcom/facebook/react/bridge/BridgeReactContext;";
+
+  static jni::local_ref<JReactApplicationContext> create(
+      jni::alias_ref<JContext> context) {
+    static const auto constructor =
+        javaClassStatic()
+            ->getConstructor<JBridgeReactContext::javaobject(
+                JContext::javaobject)>();
+    return jni::static_ref_cast<JReactApplicationContext>(
+        javaClassStatic()->newObject(constructor, context.get()));
+  }
+};
+
+class JBlobModule : public jni::JavaClass<JBlobModule> {
+ public:
+  static constexpr auto kJavaDescriptor =
+      "Lcom/facebook/react/modules/blob/BlobModule;";
+
+  static jni::local_ref<JBlobModule> create(
+      jni::alias_ref<JReactApplicationContext> reactContext) {
+    static const auto constructor =
+        javaClassStatic()
+            ->getConstructor<JBlobModule::javaobject(
+                JReactApplicationContext::javaobject)>();
+    return javaClassStatic()->newObject(constructor, reactContext.get());
+  }
+
+  void store(jni::alias_ref<jni::JArrayByte> data, const std::string& blobId) {
+    static const auto method =
+        javaClassStatic()->getMethod<void(jbyteArray, jstring)>("store");
+    method(self(), data.get(), jni::make_jstring(blobId).get());
+  }
+
+  jlong getLengthOfBlob(const std::string& blobId) {
+    static const auto method =
+        javaClassStatic()->getMethod<jlong(jstring)>("getLengthOfBlob");
+    return method(self(), jni::make_jstring(blobId).get());
+  }
+};
+
+jni::local_ref<jni::JArrayByte> makeByteArray(const jbyte* bytes, jsize size) {
+  auto javaBytes = jni::JArrayByte::newArray(size);
+  javaBytes->setRegion(0, size, bytes);
+  return javaBytes;
+}
+
+class BlobCollectorTest : public ::testing::Test {
+ protected:
+  void SetUp() override {
+    jni::ThreadScope::WithClassLoader([&] {
+      auto instrumentation = JInstrumentationRegistry::getInstrumentation();
+      auto context =
+          JBridgeReactContext::create(instrumentation->getTargetContext());
+      blobModule_ = jni::make_global(JBlobModule::create(context));
+    });
+  }
+
+  jni::global_ref<JBlobModule> blobModule_;
+};
+
+/*
+ * Bug this catches: the collector must ask Java for the blob's actual byte
+ * length and must release the same blob id when the JS host object is
+ * collected. A mismatch in method names, descriptor, object lifetime, or blob
+ * id plumbing would either report the wrong external-memory pressure to Hermes
+ * or leak blob storage after GC.
+ */
+TEST_F(
+    BlobCollectorTest,
+    testBlobCollectorReportsStoredLengthAndRemovesBlobOnDestruction) {
+  const std::string blobId{"native-collector-test"};
+  constexpr jsize blobLength = 7;
+  const std::array<jbyte, blobLength> bytes{0, 1, 1, 2, 3, 5, 8};
+
+  jni::ThreadScope::WithClassLoader([&] {
+    blobModule_->store(makeByteArray(bytes.data(), blobLength), blobId);
+    ASSERT_EQ(blobModule_->getLengthOfBlob(blobId), blobLength);
+
+    {
+      BlobCollector collector{blobModule_, blobId};
+
+      EXPECT_EQ(collector.getBlobLength(), blobLength);
+    }
+
+    EXPECT_EQ(blobModule_->getLengthOfBlob(blobId), 0);
+  });
+}
+
+} // namespace
+} // namespace facebook::react