diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 322945c..253ba7b 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -14,16 +14,26 @@ add_library(md5 STATIC ../third_party/md5/md5.cpp)
 
 ################################################################
 
-include_directories(../src/klotski_core/utils)
-add_executable(test_utils utils.cc)
-target_link_libraries(test_utils PUBLIC ${TEST_DEPS})
-add_test(NAME utils COMMAND test_utils)
+#include_directories(../src/klotski_core/utils)
+#add_executable(test_utils utils.cc)
+#target_link_libraries(test_utils PUBLIC ${TEST_DEPS})
+#add_test(NAME utils COMMAND test_utils)
+
+################################################################
+
+#include_directories(../src/klotski_core/all_cases)
+#add_executable(test_all_cases all_cases.cc)
+#target_link_libraries(test_all_cases PUBLIC ${TEST_DEPS} md5)
+#add_test(NAME all_cases COMMAND test_all_cases)
 
 ################################################################
 
+include_directories(../src/klotski_core/utils)
 include_directories(../src/klotski_core/all_cases)
-add_executable(test_all_cases all_cases.cc)
-target_link_libraries(test_all_cases PUBLIC ${TEST_DEPS} md5)
-add_test(NAME all_cases COMMAND test_all_cases)
+
+add_executable(test_basic utils.cc all_cases.cc common_code.cc)
+target_link_libraries(test_basic PUBLIC ${TEST_DEPS} md5)
+
+add_test(NAME basic COMMAND test_basic)
 
 ################################################################
diff --git a/test/all_cases.cc b/test/all_cases.cc
index 37aa211..dcb2326 100644
--- a/test/all_cases.cc
+++ b/test/all_cases.cc
@@ -1,3 +1,4 @@
+#include <thread>
 #include <cstdint>
 #include "md5.h"
 #include "all_cases.h"
@@ -9,12 +10,28 @@ using klotski::ALL_CASES_SIZE;
 using klotski::BASIC_RANGES_SIZE;
 using klotski::ALL_CASES_SIZE_SUM;
 
+const int TEST_THREAD_NUM = 8;
+
 /// basic ranges constants
 const char BASIC_RANGES_MD5[] = "6f385dc171e201089ff96bb010b47212";
 
 /// all cases constants
 const char ALL_CASES_MD5[] = "3888e9fab8d3cbb50908b12b147cfb23";
 
+/// basic ranges mutex check
+TEST(AllCases, basic_ranges_mutex) {
+    std::thread threads[TEST_THREAD_NUM];
+    EXPECT_EQ(BasicRanges::status(), BasicRanges::NO_INIT);
+    for (auto &t : threads) {
+        t = std::thread(BasicRanges::build);
+    }
+    EXPECT_EQ(BasicRanges::status(), BasicRanges::BUILDING);
+    for (auto &t : threads) {
+        t.join();
+    }
+    EXPECT_EQ(BasicRanges::status(), BasicRanges::AVAILABLE);
+}
+
 /// basic ranges size check
 TEST(AllCases, basic_ranges_size) {
     auto &basic_ranges = BasicRanges::fetch();
@@ -33,6 +50,20 @@ TEST(AllCases, basic_ranges_data) {
     EXPECT_STREQ(basic_ranges_md5.c_str(), BASIC_RANGES_MD5);
 }
 
+/// basic ranges mutex check
+TEST(AllCases, all_cases_mutex) {
+    std::thread threads[TEST_THREAD_NUM];
+    EXPECT_EQ(AllCases::status(), AllCases::NO_INIT);
+    for (auto &t : threads) {
+        t = std::thread(AllCases::build);
+    }
+    EXPECT_EQ(AllCases::status(), AllCases::BUILDING);
+    for (auto &t : threads) {
+        t.join();
+    }
+    EXPECT_EQ(AllCases::status(), AllCases::AVAILABLE);
+}
+
 /// all cases size check
 TEST(AllCases, all_cases_size) {
     auto &all_cases = AllCases::fetch();
diff --git a/test/common_code.cc b/test/common_code.cc
new file mode 100644
index 0000000..8366fbc
--- /dev/null
+++ b/test/common_code.cc
@@ -0,0 +1,3 @@
+#include "gtest/gtest.h"
+
+