diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index e362bec0..83c579ff 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -35,6 +35,7 @@ set(TEST_LIST
 	redis_unittest
 	mysql_unittest
 	facilities_unittest
+	graph_unittest
 )
 
 if (APPLE)
diff --git a/test/algo_unittest.cc b/test/algo_unittest.cc
index 5a55e886..f3c0533e 100644
--- a/test/algo_unittest.cc
+++ b/test/algo_unittest.cc
@@ -35,7 +35,7 @@ static void __arr_check(int *arr, int n)
 		EXPECT_LE(arr[i - 1], arr[i]);
 }
 
-TEST(sort, algo_unittest)
+TEST(algo_unittest, sort)
 {
 	static constexpr int n = 100000;
 	int *arr = new int[n];
@@ -65,7 +65,7 @@ TEST(sort, algo_unittest)
 	delete []arr;
 }
 
-TEST(parallel_sort, algo_unittest)
+TEST(algo_unittest, parallel_sort)
 {
 	static constexpr int n = 100000;
 	int *arr = new int[n];
diff --git a/test/facilities_unittest.cc b/test/facilities_unittest.cc
index 394540f3..2a4243fb 100644
--- a/test/facilities_unittest.cc
+++ b/test/facilities_unittest.cc
@@ -26,7 +26,7 @@
 
 #define GET_CURRENT_MICRO	std::chrono::duration_cast<std::chrono::microseconds>(std::chrono::steady_clock::now().time_since_epoch()).count()
 
-TEST(usleep, facilities_unittest)
+TEST(facilities_unittest, usleep)
 {
 	int64_t st = GET_CURRENT_MICRO;
 	WFFacilities::usleep(1000000);
@@ -34,7 +34,7 @@ TEST(usleep, facilities_unittest)
 	EXPECT_LE(ed - st, 10000000) << "usleep too slow";
 }
 
-TEST(async_usleep, facilities_unittest)
+TEST(facilities_unittest, async_usleep)
 {
 	int64_t st = GET_CURRENT_MICRO;
 	WFFacilities::async_usleep(1000000).wait();
@@ -42,7 +42,7 @@ TEST(async_usleep, facilities_unittest)
 	EXPECT_LE(ed - st, 10000000) << "async_usleep too slow";
 }
 
-TEST(request, facilities_unittest)
+TEST(facilities_unittest, request)
 {
 	protocol::HttpRequest req;
 	req.set_method(HttpMethodGet);
@@ -62,7 +62,7 @@ TEST(request, facilities_unittest)
 	}
 }
 
-TEST(async_request, facilities_unittest)
+TEST(facilities_unittest, async_request)
 {
 	protocol::HttpRequest req;
 	req.set_method(HttpMethodGet);
@@ -78,7 +78,7 @@ TEST(async_request, facilities_unittest)
 	}
 }
 
-TEST(fileIO, facilities_unittest)
+TEST(facilities_unittest, fileIO)
 {
 	uint64_t data = 0x1234;
 	ssize_t sz;
@@ -98,7 +98,7 @@ static inline void f(int i, WFFacilities::WaitGroup *wg)
 	wg->done();
 }
 
-TEST(WaitGroup, facilities_unittest)
+TEST(facilities_unittest, WaitGroup)
 {
 	WFFacilities::WaitGroup wg(100);
 
diff --git a/test/graph_unittest.cc b/test/graph_unittest.cc
new file mode 100644
index 00000000..cf236913
--- /dev/null
+++ b/test/graph_unittest.cc
@@ -0,0 +1,85 @@
+/*
+  Copyright (c) 2020 Sogou, Inc.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+  Author: Liu Yang (liuyang216492@sogou-inc.com)
+*/
+
+#include <atomic>
+#include <gtest/gtest.h>
+
+#include "workflow/WFTaskFactory.h"
+#include "workflow/WFFacilities.h"
+
+static SubTask *create_task(int& target)
+{
+	static std::atomic<int> generator;
+	return WFTaskFactory::create_timer_task(0, [&](WFTimerTask *)
+	{
+		target = generator++;
+	});
+}
+
+TEST(graph_unittest, WFGraphTask1)
+{
+	WFFacilities::WaitGroup wait_group(1);
+
+	auto graph = WFTaskFactory::create_graph_task([&wait_group](WFGraphTask *){ wait_group.done(); });
+
+	int ta, tb, tc, td;
+
+	auto& a = graph->create_graph_node(create_task(ta));
+	auto& b = graph->create_graph_node(create_task(tb));
+	auto& c = graph->create_graph_node(create_task(tc));
+	auto& d = graph->create_graph_node(create_task(td));
+
+	a --> b <-- c --> d --> a;
+	c --> a;
+
+	graph->start();
+	wait_group.wait();
+
+	EXPECT_LT(ta, tb);
+	EXPECT_LT(tc, tb);
+	EXPECT_LT(tc, td);
+	EXPECT_LT(td, ta);
+	EXPECT_LT(tc, ta);
+}
+
+TEST(graph_unittest, WFGraphTask2)
+{
+	WFFacilities::WaitGroup wait_group(1);
+
+	auto graph = WFTaskFactory::create_graph_task([&wait_group](WFGraphTask *){ wait_group.done(); });
+
+	constexpr int N = 4096 - 1;
+
+	auto target = new int[N];
+	auto node = new WFGraphNode *[N];
+
+	for (int i = 0; i < N; i++)
+		node[i] = &graph->create_graph_node(create_task(target[i]));
+
+	for (int i = 1; i < N; i++)
+		node[i]->precede(*node[(i - 1) / 2]);
+
+	graph->start();
+	wait_group.wait();
+
+	for (int i = 1; i < N; i++)
+		EXPECT_LT(target[i], target[(i - 1) / 2]);
+
+	delete[] target;
+	delete[] node;
+}
diff --git a/test/http_unittest.cc b/test/http_unittest.cc
index 060dfeab..2e0934c1 100644
--- a/test/http_unittest.cc
+++ b/test/http_unittest.cc
@@ -36,7 +36,7 @@ static void __http_process(WFHttpTask *task)
 	resp->add_header_pair("Content-Type", "text/plain");
 }
 
-TEST(WFHttpTask1, http_unittest)
+TEST(http_unittest, WFHttpTask1)
 {
 	std::mutex mutex;
 	std::condition_variable cond;
@@ -69,7 +69,7 @@ TEST(WFHttpTask1, http_unittest)
 	lock.unlock();
 }
 
-TEST(WFHttpTask2, http_unittest)
+TEST(http_unittest, WFHttpTask2)
 {
 	std::mutex mutex;
 	std::condition_variable cond;
@@ -98,7 +98,7 @@ TEST(WFHttpTask2, http_unittest)
 	lock.unlock();
 }
 
-TEST(WFHttpTask3, http_unittest)
+TEST(http_unittest, WFHttpTask3)
 {
 	FILE *f;
 	f = fopen("server.crt", "w");
diff --git a/test/mysql_unittest.cc b/test/mysql_unittest.cc
index 29f186b1..a2d353f9 100644
--- a/test/mysql_unittest.cc
+++ b/test/mysql_unittest.cc
@@ -48,7 +48,7 @@ static void test_client(const char *url, const char *sql, std::mutex& mutex, std
 	task->start();
 }
 
-TEST(WFMySQLTask1, mysql_unittest)
+TEST(mysql_unittest, WFMySQLTask1)
 {
 	std::mutex mutex;
 	std::condition_variable cond;
diff --git a/test/redis_unittest.cc b/test/redis_unittest.cc
index 62664589..69bc19a9 100644
--- a/test/redis_unittest.cc
+++ b/test/redis_unittest.cc
@@ -136,7 +136,7 @@ static void test_client(const char *url, std::mutex& mutex, std::condition_varia
 	flow.start();
 }
 
-TEST(WFRedisTask1, redis_unittest)
+TEST(redis_unittest, WFRedisTask1)
 {
 	std::mutex mutex;
 	std::condition_variable cond;
@@ -153,7 +153,7 @@ TEST(WFRedisTask1, redis_unittest)
 	server.stop();
 }
 
-TEST(WFRedisTask2, redis_unittest)
+TEST(redis_unittest, WFRedisTask2)
 {
 	std::mutex mutex;
 	std::condition_variable cond;
diff --git a/test/task_unittest.cc b/test/task_unittest.cc
index 3df54a6a..a85f1250 100644
--- a/test/task_unittest.cc
+++ b/test/task_unittest.cc
@@ -31,7 +31,7 @@
 
 #define GET_CURRENT_MICRO	std::chrono::duration_cast<std::chrono::microseconds>(std::chrono::steady_clock::now().time_since_epoch()).count()
 
-TEST(WFTimerTask, task_unittest)
+TEST(task_unittest, WFTimerTask)
 {
 	std::mutex mutex;
 	std::condition_variable cond;
@@ -56,7 +56,7 @@ TEST(WFTimerTask, task_unittest)
 	EXPECT_LE(ed - st, 10000000) << "Timer Task too slow";
 }
 
-TEST(WFCounterTask1, task_unittest)
+TEST(task_unittest, WFCounterTask1)
 {
 	std::mutex mutex;
 	std::condition_variable cond;
@@ -92,7 +92,7 @@ TEST(WFCounterTask1, task_unittest)
 	lock.unlock();
 }
 
-TEST(WFCounterTask2, task_unittest)
+TEST(task_unittest, WFCounterTask2)
 {
 	std::mutex mutex;
 	std::condition_variable cond;
@@ -125,7 +125,7 @@ TEST(WFCounterTask2, task_unittest)
 	lock.unlock();
 }
 
-TEST(WFGoTask, task_unittest)
+TEST(task_unittest, WFGoTask)
 {
 	srand(time(NULL));
 	std::mutex mutex;
@@ -155,7 +155,7 @@ TEST(WFGoTask, task_unittest)
 	EXPECT_EQ(edit_inner, 100);
 }
 
-TEST(WFThreadTask, task_unittest)
+TEST(task_unittest, WFThreadTask)
 {
 	std::mutex mutex;
 	std::condition_variable cond;
@@ -195,7 +195,7 @@ TEST(WFThreadTask, task_unittest)
 	lock.unlock();
 }
 
-TEST(WFFileIOTask, task_unittest)
+TEST(task_unittest, WFFileIOTask)
 {
 	srand(time(NULL));
 	std::mutex mutex;