xplat/js/react-native-github/packages/react-native/ReactAndroid/src/main/jni/first-party/yogajni/jni/corefunctions.cpp

packages/react-native/ReactAndroid/src/main/jni/first-party/yogajni/jni/tests/corefunctionsTest.cpp

@@ -0,0 +1,247 @@
+/*
+ * 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 "corefunctions.h"
+
+#include <gtest/gtest.h>
+#include <jni.h>
+#include "YogaJniException.h"
+
+namespace facebook::yoga::vanillajni {
+namespace {
+
+// A single byte handed out as opaque, never-dereferenced JNI handles (jclass,
+// jobject, jthrowable, jmethodID). The functions under test only compare these
+// against nullptr; they never look inside them.
+char gFakeHandleStorage = 0;
+
+template <typename T>
+T fakeHandle() {
+  return reinterpret_cast<T>(&gFakeHandleStorage);
+}
+
+// Overlay for JNIEnv. The real _JNIEnv is standard-layout with a single leading
+// functions pointer, so a FakeEnv* can be passed anywhere a JNIEnv* is expected
+// and cast back inside the interface callbacks to reach the per-instance,
+// test-controlled behavior below.
+struct FakeEnv {
+  const JNINativeInterface* functions;
+
+  jboolean exceptionCheckResult;
+  jthrowable exceptionOccurredResult;
+  jobject newGlobalRefResult;
+  jclass findClassResult;
+  jmethodID getMethodIdResult;
+  jobject newObjectResult;
+
+  int exceptionCheckCalls;
+  int exceptionClearCalls;
+};
+
+struct FakeVm {
+  const JNIInvokeInterface* functions;
+  JNIEnv* envToReturn;
+  jint getEnvResult;
+};
+
+FakeEnv* asFake(JNIEnv* env) {
+  return reinterpret_cast<FakeEnv*>(env);
+}
+
+jboolean fakeExceptionCheck(JNIEnv* env) {
+  auto* self = asFake(env);
+  ++self->exceptionCheckCalls;
+  return self->exceptionCheckResult;
+}
+
+jthrowable fakeExceptionOccurred(JNIEnv* env) {
+  return asFake(env)->exceptionOccurredResult;
+}
+
+void fakeExceptionClear(JNIEnv* env) {
+  ++asFake(env)->exceptionClearCalls;
+}
+
+jobject fakeNewGlobalRef(JNIEnv* env, jobject /*obj*/) {
+  return asFake(env)->newGlobalRefResult;
+}
+
+void fakeDeleteGlobalRef(JNIEnv* /*env*/, jobject /*obj*/) {}
+
+jclass fakeFindClass(JNIEnv* env, const char* /*name*/) {
+  return asFake(env)->findClassResult;
+}
+
+jmethodID fakeGetMethodID(
+    JNIEnv* env,
+    jclass /*clazz*/,
+    const char* /*name*/,
+    const char* /*sig*/) {
+  return asFake(env)->getMethodIdResult;
+}
+
+jobject fakeNewObjectV(
+    JNIEnv* env,
+    jclass /*clazz*/,
+    jmethodID /*methodId*/,
+    va_list /*args*/) {
+  return asFake(env)->newObjectResult;
+}
+
+const JNINativeInterface& fakeNativeInterface() {
+  static const JNINativeInterface table = [] {
+    JNINativeInterface t{};
+    t.ExceptionCheck = &fakeExceptionCheck;
+    t.ExceptionOccurred = &fakeExceptionOccurred;
+    t.ExceptionClear = &fakeExceptionClear;
+    t.NewGlobalRef = &fakeNewGlobalRef;
+    t.DeleteGlobalRef = &fakeDeleteGlobalRef;
+    t.FindClass = &fakeFindClass;
+    t.GetMethodID = &fakeGetMethodID;
+    t.NewObjectV = &fakeNewObjectV;
+    return t;
+  }();
+  return table;
+}
+
+jint fakeGetEnv(JavaVM* vm, void** out, jint /*version*/) {
+  auto* self = reinterpret_cast<FakeVm*>(vm);
+  *out = self->envToReturn;
+  return self->getEnvResult;
+}
+
+const JNIInvokeInterface& fakeInvokeInterface() {
+  static const JNIInvokeInterface table = [] {
+    JNIInvokeInterface t{};
+    t.GetEnv = &fakeGetEnv;
+    return t;
+  }();
+  return table;
+}
+
+// getCurrentEnv() (invoked while wrapping a Java exception into a
+// YogaJniException) reads a process-global JavaVM that is latched exactly once
+// by the first ensureInitialized() call, so it must stay valid for the entire
+// process. This plumbing env/VM exists solely to satisfy that constraint: it
+// returns constant, non-null JNI handles and is never mutated by any test.
+// All per-test, mutable state lives on each fixture's own FakeEnv, so tests
+// stay fully isolated from one another.
+FakeEnv& plumbingEnv() {
+  static FakeEnv env{
+      .functions = &fakeNativeInterface(),
+      .exceptionCheckResult = JNI_FALSE,
+      .exceptionOccurredResult = fakeHandle<jthrowable>(),
+      .newGlobalRefResult = fakeHandle<jobject>(),
+      .findClassResult = fakeHandle<jclass>(),
+      .getMethodIdResult = fakeHandle<jmethodID>(),
+      .newObjectResult = fakeHandle<jobject>(),
+      .exceptionCheckCalls = 0,
+      .exceptionClearCalls = 0};
+  return env;
+}
+
+JNIEnv* plumbingJniEnv() {
+  return reinterpret_cast<JNIEnv*>(&plumbingEnv());
+}
+
+FakeVm& plumbingVm() {
+  static FakeVm vm{
+      .functions = &fakeInvokeInterface(),
+      .envToReturn = plumbingJniEnv(),
+      .getEnvResult = JNI_OK};
+  return vm;
+}
+
+JavaVM* plumbingJavaVm() {
+  return reinterpret_cast<JavaVM*>(&plumbingVm());
+}
+
+class CoreFunctionsTest : public ::testing::Test {
+ protected:
+  // Latch the process-global JavaVM exactly once for the whole suite so that
+  // getCurrentEnv() (used when wrapping exceptions) has a valid, stable env.
+  static void SetUpTestSuite() {
+    JNIEnv* out = nullptr;
+    ensureInitialized(&out, plumbingJavaVm());
+  }
+
+  void SetUp() override {
+    env_ = FakeEnv{
+        .functions = &fakeNativeInterface(),
+        .exceptionCheckResult = JNI_FALSE,
+        .exceptionOccurredResult = fakeHandle<jthrowable>(),
+        .newGlobalRefResult = fakeHandle<jobject>(),
+        .findClassResult = fakeHandle<jclass>(),
+        .getMethodIdResult = fakeHandle<jmethodID>(),
+        .newObjectResult = fakeHandle<jobject>(),
+        .exceptionCheckCalls = 0,
+        .exceptionClearCalls = 0};
+  }
+
+  JNIEnv* env() {
+    return reinterpret_cast<JNIEnv*>(&env_);
+  }
+
+  // Owned per test instance; each test observes and mutates only its own copy.
+  FakeEnv env_{};
+};
+
+TEST_F(CoreFunctionsTest, ensureInitializedReturnsVersionAndPopulatesEnv) {
+  JNIEnv* out = nullptr;
+
+  jint result = ensureInitialized(&out, plumbingJavaVm());
+
+  EXPECT_EQ(JNI_VERSION_1_6, result);
+  // The out-param must be populated with the JNIEnv that the VM GetEnv hook
+  // wrote, not left untouched.
+  EXPECT_EQ(plumbingJniEnv(), out);
+}
+
+TEST_F(CoreFunctionsTest, assertNoPendingJniExceptionReturnsWhenNoException) {
+  env_.exceptionCheckResult = JNI_FALSE;
+
+  EXPECT_NO_THROW(assertNoPendingJniException(env()));
+  // A clean env must be left alone: no attempt to clear a (non-existent)
+  // pending exception.
+  EXPECT_EQ(0, env_.exceptionClearCalls);
+}
+
+TEST_F(CoreFunctionsTest, assertNoPendingJniExceptionClearsAndWrapsPending) {
+  env_.exceptionCheckResult = JNI_TRUE;
+  env_.exceptionOccurredResult = fakeHandle<jthrowable>();
+
+  EXPECT_THROW(assertNoPendingJniException(env()), YogaJniException);
+  // The pending Java exception must be cleared exactly once before it is
+  // rethrown as a C++ exception, otherwise it would leak into the next JNI
+  // call.
+  EXPECT_EQ(1, env_.exceptionClearCalls);
+}
+
+TEST_F(
+    CoreFunctionsTest,
+    assertNoPendingJniExceptionIfSkipsCheckWhenConditionFalse) {
+  // Arrange a pending exception that would throw if it were inspected.
+  env_.exceptionCheckResult = JNI_TRUE;
+  env_.exceptionOccurredResult = fakeHandle<jthrowable>();
+
+  EXPECT_NO_THROW(assertNoPendingJniExceptionIf(env(), false));
+  // With a false condition the env must not be probed at all.
+  EXPECT_EQ(0, env_.exceptionCheckCalls);
+}
+
+TEST_F(
+    CoreFunctionsTest,
+    assertNoPendingJniExceptionIfThrowsWhenConditionTrueWithoutPending) {
+  // Condition is true but there is no pending JNI exception, so the function
+  // must still surface a failure by synthesizing a YogaJniException.
+  env_.exceptionCheckResult = JNI_FALSE;
+
+  EXPECT_THROW(assertNoPendingJniExceptionIf(env(), true), YogaJniException);
+}
+
+} // namespace
+} // namespace facebook::yoga::vanillajni