diff --git a/src/klotski_core/short_code/short_code.h b/src/klotski_core/short_code/short_code.h
index 2bf5156..59726e5 100644
--- a/src/klotski_core/short_code/short_code.h
+++ b/src/klotski_core/short_code/short_code.h
@@ -35,7 +35,7 @@ namespace klotski {
     public:
         enum Mode {NORMAL, FAST};
 
-        inline bool valid() const;
+        bool valid() const;
         static void speed_up(enum Mode mode);
         static bool check(uint32_t short_code);
 
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 720b745..fb7085d 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -21,13 +21,12 @@ include_directories(../src/klotski_core/raw_code)
 include_directories(../src/klotski_core/short_code)
 include_directories(../src/klotski_core/common_code)
 
-add_executable(test_basic utils.cc all_cases.cc raw_code.cc common_code.cc)
+add_executable(test_basic utils.cc all_cases.cc)
 target_link_libraries(test_basic PUBLIC ${TEST_DEPS} md5)
 add_test(NAME basic COMMAND test_basic)
 
-# TODO: combine into basic after develop complete
-add_executable(test_raw_code raw_code.cc)
-target_link_libraries(test_raw_code ${TEST_DEPS})
-add_test(NAME raw_code COMMAND test_raw_code)
+add_executable(test_codec short_code.cc raw_code.cc common_code.cc)
+target_link_libraries(test_codec ${TEST_DEPS})
+add_test(NAME codec COMMAND test_codec)
 
 ################################################################
diff --git a/test/common_code.cc b/test/common_code.cc
index 57533d9..eea92c7 100644
--- a/test/common_code.cc
+++ b/test/common_code.cc
@@ -65,8 +65,10 @@ TEST(CommonCode, code_string) {
 }
 
 TEST(CommonCode, operators) {
-    EXPECT_EQ(CommonCode(TEST_CODE), CommonCode(TEST_CODE)); // operator `==`
+    std::cout.setstate(std::ios::failbit); // hide std::cout content
     std::cout << "TEST OUTPUT -> " << CommonCode(TEST_CODE) << std::endl; // ostream test
+    std::cout.clear();
+    EXPECT_EQ(CommonCode(TEST_CODE), CommonCode(TEST_CODE)); // operator `==`
     EXPECT_EQ((uint64_t)CommonCode(TEST_CODE), TEST_CODE); // convert as uint64_t
 }
 
diff --git a/test/raw_code.cc b/test/raw_code.cc
index ebd2bce..ba26c71 100644
--- a/test/raw_code.cc
+++ b/test/raw_code.cc
@@ -28,8 +28,10 @@ TEST(RawCode, code_verify) {
 }
 
 TEST(RawCode, operators) {
-    EXPECT_EQ(RawCode(TEST_CODE), RawCode(TEST_CODE)); // operator `==`
+    std::cout.setstate(std::ios::failbit); // hide std::cout content
     std::cout << "TEST OUTPUT" << std::endl << RawCode(TEST_CODE); // ostream test
+    std::cout.clear();
+    EXPECT_EQ(RawCode(TEST_CODE), RawCode(TEST_CODE)); // operator `==`
     EXPECT_EQ((uint64_t)RawCode(TEST_CODE), TEST_CODE); // convert as uint64_t
 }
 
diff --git a/test/short_code.cc b/test/short_code.cc
new file mode 100644
index 0000000..a45ed08
--- /dev/null
+++ b/test/short_code.cc
@@ -0,0 +1,117 @@
+#include <thread>
+#include <algorithm>
+#include "all_cases.h"
+#include "short_code.h"
+#include "gtest/gtest.h"
+
+using klotski::AllCases;
+using klotski::ShortCode;
+using klotski::CommonCode;
+using klotski::BasicRanges;
+
+const static uint64_t TEST_CODE = 4091296;
+const static std::string TEST_CODE_STR = "4WVE1";
+
+TEST(ShortCode, speed_up) {
+    std::thread threads[4];
+
+    /// speed up to normal mode
+    EXPECT_EQ(BasicRanges::status(), BasicRanges::NO_INIT);
+    for (auto &t : threads) {
+        t = std::thread(ShortCode::speed_up, ShortCode::NORMAL);
+    }
+    EXPECT_EQ(BasicRanges::status(), BasicRanges::BUILDING);
+    for (auto &t : threads) {
+        t.join();
+    }
+    EXPECT_EQ(BasicRanges::status(), BasicRanges::AVAILABLE);
+
+    /// speed up to fast mode
+    EXPECT_EQ(AllCases::status(), AllCases::NO_INIT);
+    for (auto &t : threads) {
+        t = std::thread(ShortCode::speed_up, ShortCode::FAST);
+    }
+    EXPECT_EQ(AllCases::status(), AllCases::BUILDING);
+    for (auto &t : threads) {
+        t.join();
+    }
+    EXPECT_EQ(AllCases::status(), AllCases::AVAILABLE);
+}
+
+TEST(ShortCode, code_verify) {
+    std::thread threads[16];
+    auto test = [](uint64_t head) {
+        for (const auto &range : AllCases::fetch()[head]) {
+            auto code = (uint32_t)ShortCode::from_common_code(head << 32 | range);
+            EXPECT_EQ(ShortCode::check(code), true); // test static `check` interface
+            auto tmp = ShortCode::unsafe_create(code); // test dynamic `valid` interface
+            EXPECT_EQ(tmp.valid(), true);
+        }
+    };
+    for (uint64_t head = 0; head < 16; ++head) {
+        threads[head] = std::thread(test, head); // ensure that short code fast mode enabled
+    }
+    for (auto &t : threads) {
+        t.join();
+    }
+}
+
+TEST(ShortCode, code_string) {
+    std::thread threads[16];
+    auto test = [](uint64_t head) {
+        for (const auto &range : AllCases::fetch()[head]) {
+            std::string code_str;
+            auto short_code = ShortCode::from_common_code(head << 32 | range);
+
+            code_str = short_code.to_string();
+            EXPECT_EQ(code_str.size(), 5); // length = 5
+            for (const auto &c : code_str) {
+                EXPECT_EQ(
+                    ((c >= '1' && c <= '9') || (c >= 'A' && c <= 'Z'))
+                        && (c != 'I' && c != 'L' && c != 'O'), true
+                );
+            }
+            EXPECT_EQ(ShortCode::from_string(code_str), short_code); // test upper cases
+            std::transform(code_str.begin(), code_str.end(), code_str.begin(), ::tolower);
+            EXPECT_EQ(ShortCode::from_string(code_str), short_code); // test lower cases
+        }
+    };
+    for (uint64_t head = 0; head < 16; ++head) {
+        threads[head] = std::thread(test, head); // ensure that short code fast mode enabled
+    }
+    for (auto &t : threads) {
+        t.join();
+    }
+}
+
+TEST(ShortCode, operators) {
+    std::cout.setstate(std::ios::failbit); // hide std::cout content
+    std::cout << "TEST OUTPUT -> " << ShortCode(TEST_CODE) << std::endl; // ostream test
+    std::cout.clear();
+    EXPECT_EQ(ShortCode(TEST_CODE), ShortCode(TEST_CODE)); // operator `==`
+    EXPECT_EQ((uint32_t)ShortCode(TEST_CODE), TEST_CODE); // convert as uint64_t
+}
+
+TEST(ShortCode, code_convert) {
+    EXPECT_STREQ(ShortCode(TEST_CODE).to_string().c_str(), TEST_CODE_STR.c_str());
+    EXPECT_EQ(ShortCode(ShortCode(TEST_CODE).to_string()), ShortCode(TEST_CODE));
+    EXPECT_EQ(ShortCode(TEST_CODE).to_common_code(), CommonCode::from_short_code(TEST_CODE));
+    EXPECT_EQ(ShortCode(TEST_CODE).unwrap(), TEST_CODE);
+}
+
+TEST(ShortCode, constructors) {
+    EXPECT_EQ(ShortCode(TEST_CODE).unwrap(), TEST_CODE);
+    EXPECT_EQ(ShortCode(TEST_CODE_STR).unwrap(), TEST_CODE);
+    EXPECT_EQ(ShortCode(CommonCode::from_short_code(TEST_CODE)).unwrap(), TEST_CODE);
+}
+
+TEST(ShortCode, initializate) {
+    EXPECT_EQ(ShortCode::create(TEST_CODE).unwrap(), TEST_CODE);
+    EXPECT_EQ(ShortCode::from_string(TEST_CODE_STR).unwrap(), TEST_CODE);
+    EXPECT_EQ(ShortCode::unsafe_create(TEST_CODE).unwrap(), TEST_CODE);
+
+    auto common_code = CommonCode::from_short_code(TEST_CODE);
+    EXPECT_EQ(ShortCode::from_common_code(common_code).unwrap(), TEST_CODE);
+    EXPECT_EQ(ShortCode::from_common_code(common_code.unwrap()).unwrap(), TEST_CODE);
+    EXPECT_EQ(ShortCode::from_common_code(common_code.to_string()).unwrap(), TEST_CODE);
+}