diff --git a/cmake/unit_tests.cmake b/cmake/unit_tests.cmake
index 619afbe..06d510d 100644
--- a/cmake/unit_tests.cmake
+++ b/cmake/unit_tests.cmake
@@ -30,6 +30,7 @@ add_executable(alltests
 	test/webfuse/mocks/mock_request.cc
 	test/webfuse/mocks/mock_provider_client.cc
 	test/webfuse/mocks/mock_provider.cc
+	test/webfuse/mocks/mock_fuse.cc
 	test/webfuse//tests/core/test_util.cc
 	test/webfuse/tests/core/test_container_of.cc
 	test/webfuse/tests/core/test_string.cc
@@ -45,6 +46,7 @@ add_executable(alltests
 	test/webfuse/tests/adapter/test_authenticators.cc
 	test/webfuse/tests/adapter/test_mountpoint.cc
 	test/webfuse/tests/adapter/test_fuse_req.cc
+	test/webfuse/tests/adapter/operation/test_open.cc
 	test/webfuse/tests/provider/test_url.cc
 	test/webfuse/tests/provider/test_client_protocol.cc
 	test/webfuse/tests/provider/operation/test_close.cc
@@ -67,6 +69,9 @@ target_link_libraries(alltests PUBLIC
 	-Wl,--wrap=wf_timer_dispose
 	-Wl,--wrap=wf_timer_start
 	-Wl,--wrap=wf_timer_cancel
+	-Wl,--wrap=fuse_req_userdata
+	-Wl,--wrap=fuse_reply_open
+	-Wl,--wrap=fuse_reply_err
 
 	webfuse-adapter-static
 	webfuse-provider-static
diff --git a/lib/webfuse/adapter/impl/operation/open.c b/lib/webfuse/adapter/impl/operation/open.c
index 8e21100..07d8ea9 100644
--- a/lib/webfuse/adapter/impl/operation/open.c
+++ b/lib/webfuse/adapter/impl/operation/open.c
@@ -22,7 +22,7 @@ static void wf_impl_operation_open_finished(
 	if (NULL != result)
 	{
         json_t * handle_holder = json_object_get(result, "handle");
-        if ((NULL != handle_holder) && (json_is_integer(handle_holder))) 
+        if (json_is_integer(handle_holder))
         {
             file_info.fh = json_integer_value(handle_holder);
         }
diff --git a/test/webfuse/mocks/mock_fuse.cc b/test/webfuse/mocks/mock_fuse.cc
new file mode 100644
index 0000000..fa2f981
--- /dev/null
+++ b/test/webfuse/mocks/mock_fuse.cc
@@ -0,0 +1,28 @@
+#include "webfuse/mocks/mock_fuse.hpp"
+#include "webfuse/utils/wrap.hpp"
+
+extern "C"
+{
+static webfuse_test::FuseMock * webfuse_test_FuseMock = nullptr;
+
+WF_WRAP_FUNC1(webfuse_test_FuseMock, void*, fuse_req_userdata, fuse_req_t);
+WF_WRAP_FUNC2(webfuse_test_FuseMock, int, fuse_reply_open, fuse_req_t, const struct fuse_file_info *);
+WF_WRAP_FUNC2(webfuse_test_FuseMock, int, fuse_reply_err, fuse_req_t, int);
+
+}
+
+namespace webfuse_test
+{
+
+FuseMock::FuseMock()
+{
+    webfuse_test_FuseMock = this;
+}
+
+FuseMock::~FuseMock()
+{
+    webfuse_test_FuseMock = nullptr;
+}
+
+
+}
\ No newline at end of file
diff --git a/test/webfuse/mocks/mock_fuse.hpp b/test/webfuse/mocks/mock_fuse.hpp
new file mode 100644
index 0000000..ed6e6ff
--- /dev/null
+++ b/test/webfuse/mocks/mock_fuse.hpp
@@ -0,0 +1,19 @@
+#include "webfuse/adapter/impl/fuse_wrapper.h"
+#include <gmock/gmock.h>
+
+namespace webfuse_test
+{
+
+class FuseMock
+{
+public:
+    FuseMock();
+    virtual ~FuseMock();
+
+    MOCK_METHOD1(fuse_req_userdata, void *(fuse_req_t req));
+    MOCK_METHOD2(fuse_reply_open, int (fuse_req_t req, const struct fuse_file_info *fi));
+    MOCK_METHOD2(fuse_reply_err, int (fuse_req_t req, int err));
+};
+
+
+}
\ No newline at end of file
diff --git a/test/webfuse/tests/adapter/operation/test_open.cc b/test/webfuse/tests/adapter/operation/test_open.cc
new file mode 100644
index 0000000..d1b5960
--- /dev/null
+++ b/test/webfuse/tests/adapter/operation/test_open.cc
@@ -0,0 +1,28 @@
+#include "webfuse/adapter/impl/operations.h"
+#include "webfuse/mocks/mock_fuse.hpp"
+#include "webfuse/adapter/impl/session.h"
+
+#include <gtest/gtest.h>
+
+using webfuse_test::FuseMock;
+using testing::_;
+using testing::Return;
+
+TEST(wf_impl_operation_open, fail_rpc_null)
+{
+    wf_impl_session session;
+    memset(&session, 0, sizeof(session));
+    wf_impl_operations_context context =
+        {&session, 1.0f, nullptr };
+
+    FuseMock fuse;
+    EXPECT_CALL(fuse, fuse_req_userdata(_)).Times(1)
+        .WillOnce(Return(reinterpret_cast<void*>(&context)));
+    EXPECT_CALL(fuse, fuse_reply_err(_, ENOENT)).Times(1)
+        .WillOnce(Return(0));
+
+    fuse_req_t request = nullptr;
+    fuse_ino_t inode = 1;
+    fuse_file_info * file_info = nullptr;
+    wf_impl_operation_open(request, inode, file_info);
+}
\ No newline at end of file