test: cover builtin shader manifest resolution outside project cwd

tests/Resources/Shader/test_shader_loader.cpp

@@ -426,4 +426,69 @@ TEST(ShaderLoader, ResourceManagerLazilyLoadsBuiltinForwardLitShader) {
     manager.Shutdown();
 }
 
+TEST(ShaderLoader, ResourceManagerLoadsBuiltinShadersOutsideProjectWorkingDirectory) {
+    namespace fs = std::filesystem;
+
+    ResourceManager& manager = ResourceManager::Get();
+    const fs::path previousPath = fs::current_path();
+    const String previousResourceRoot = manager.GetResourceRoot();
+    const fs::path isolatedWorkingDirectory = fs::temp_directory_path() / "xc_builtin_shader_out_of_tree";
+
+    fs::remove_all(isolatedWorkingDirectory);
+    fs::create_directories(isolatedWorkingDirectory);
+
+    manager.Shutdown();
+    manager.SetResourceRoot("");
+    fs::current_path(isolatedWorkingDirectory);
+
+    auto expectBuiltinShader = [&](const String& path,
+                                   const char* passName,
+                                   ShaderType stage,
+                                   ShaderBackend backend,
+                                   const char* marker) {
+        const ResourceHandle<Shader> shaderHandle = manager.Load<Shader>(path);
+        EXPECT_TRUE(shaderHandle.IsValid()) << path.CStr();
+        if (!shaderHandle.IsValid()) {
+            return;
+        }
+
+        EXPECT_NE(shaderHandle->FindPass(passName), nullptr) << path.CStr();
+        const ShaderStageVariant* variant = shaderHandle->FindVariant(passName, stage, backend);
+        EXPECT_NE(variant, nullptr) << path.CStr();
+        if (variant != nullptr) {
+            EXPECT_NE(std::string(variant->sourceCode.CStr()).find(marker), std::string::npos) << path.CStr();
+        }
+    };
+
+    expectBuiltinShader(
+        GetBuiltinForwardLitShaderPath(),
+        "ForwardLit",
+        ShaderType::Vertex,
+        ShaderBackend::D3D12,
+        "XC_BUILTIN_FORWARD_LIT_D3D12_VS");
+    expectBuiltinShader(
+        GetBuiltinObjectIdShaderPath(),
+        "ObjectId",
+        ShaderType::Fragment,
+        ShaderBackend::Vulkan,
+        "XC_BUILTIN_OBJECT_ID_VULKAN_PS");
+    expectBuiltinShader(
+        GetBuiltinObjectIdOutlineShaderPath(),
+        "ObjectIdOutline",
+        ShaderType::Fragment,
+        ShaderBackend::D3D12,
+        "XC_BUILTIN_OBJECT_ID_OUTLINE_D3D12_PS");
+    expectBuiltinShader(
+        GetBuiltinInfiniteGridShaderPath(),
+        "InfiniteGrid",
+        ShaderType::Fragment,
+        ShaderBackend::D3D12,
+        "XC_BUILTIN_INFINITE_GRID_D3D12_PS");
+
+    fs::current_path(previousPath);
+    manager.SetResourceRoot(previousResourceRoot);
+    manager.Shutdown();
+    fs::remove_all(isolatedWorkingDirectory);
+}
+
 } // namespace