diff --git a/packages/react-native/ReactCxxPlatform/react/io/tests/fbcode/ResourceLoaderTest.cpp b/packages/react-native/ReactCxxPlatform/react/io/tests/fbcode/ResourceLoaderTest.cpp
new file mode 100644
index 000000000000..e68510a728f1
--- /dev/null
+++ b/packages/react-native/ReactCxxPlatform/react/io/tests/fbcode/ResourceLoaderTest.cpp
@@ -0,0 +1,38 @@
+/*
+ * 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 <gtest/gtest.h>
+#include <react/io/ResourceLoader.h>
+
+namespace facebook::react {
+
+// Exercises the path-classification contract that ResourceLoader::isDirectory
+// and isFile rely on for their "absolute path" fast path. This is pure lexical
+// logic and performs no filesystem, JNI, or asset-manager access.
+class ResourceLoaderTest : public ::testing::Test {};
+
+TEST_F(ResourceLoaderTest, testIsAbsolutePathRejectsRelativePaths) {
+  // Relative paths must never take the absolute fast path, regardless of the
+  // separator or leading "./" or "../" components.
+  EXPECT_FALSE(ResourceLoader::isAbsolutePath("assets/index.bundle"));
+  EXPECT_FALSE(ResourceLoader::isAbsolutePath("./config.json"));
+  EXPECT_FALSE(ResourceLoader::isAbsolutePath("../parent/file.txt"));
+  EXPECT_FALSE(ResourceLoader::isAbsolutePath("bundle.js"));
+}
+
+TEST_F(ResourceLoaderTest, testIsAbsolutePathRejectsEmptyPath) {
+  // An empty path has no root and must never be treated as absolute; otherwise
+  // isDirectory/isFile would take the absolute fast path for an invalid input.
+  EXPECT_FALSE(ResourceLoader::isAbsolutePath(""));
+}
+
+TEST_F(ResourceLoaderTest, testIsAbsolutePathAcceptsAbsolutePaths) {
+  EXPECT_TRUE(ResourceLoader::isAbsolutePath("/data/data/com.app/bundle.js"));
+  EXPECT_TRUE(ResourceLoader::isAbsolutePath("/"));
+}
+
+} // namespace facebook::react