diff --git a/src/klotski_core/common_code/common_code.h b/src/klotski_core/common_code/common_code.h
index fbb45ea..4f7ad87 100644
--- a/src/klotski_core/common_code/common_code.h
+++ b/src/klotski_core/common_code/common_code.h
@@ -123,6 +123,9 @@ inline bool operator==(uint64_t c1, const CommonCode &c2) noexcept { return c1 =
 inline bool operator!=(uint64_t c1, const CommonCode &c2) noexcept { return c1 != c2.unwrap(); }
 inline bool operator==(const CommonCode &c1, uint64_t c2) noexcept { return c1.unwrap() == c2; }
 inline bool operator!=(const CommonCode &c1, uint64_t c2) noexcept { return c1.unwrap() != c2; }
+
+inline bool operator<(const CommonCode &c1, const CommonCode &c2) noexcept { return c1.unwrap() < c2.unwrap(); }
+inline bool operator>(const CommonCode &c1, const CommonCode &c2) noexcept { return c1.unwrap() > c2.unwrap(); }
 inline bool operator==(const CommonCode &c1, const CommonCode &c2) noexcept { return c1.unwrap() == c2.unwrap(); }
 inline bool operator!=(const CommonCode &c1, const CommonCode &c2) noexcept { return c1.unwrap() != c2.unwrap(); }
 
diff --git a/test/codec/common_code.cc b/test/codec/common_code.cc
index acfdf53..169dec3 100644
--- a/test/codec/common_code.cc
+++ b/test/codec/common_code.cc
@@ -103,6 +103,9 @@ TEST(CommonCode, operators) {
     EXPECT_NE(TEST_CODE + 1, CommonCode(TEST_CODE)); // uint64_t != CommonCode
     EXPECT_NE(CommonCode(TEST_CODE), TEST_CODE + 1); // CommonCode != uint64_t
     EXPECT_NE(CommonCode(TEST_CODE), CommonCode::unsafe_create(TEST_CODE + 1)); // CommonCode != CommonCode
+
+    EXPECT_LT(CommonCode(TEST_CODE), CommonCode::unsafe_create(TEST_CODE + 1)); // CommonCode < CommonCode
+    EXPECT_GT(CommonCode::unsafe_create(TEST_CODE + 1), CommonCode(TEST_CODE)); // CommonCode > CommonCode
 }
 
 TEST(CommonCode, code_convert) {
diff --git a/test/group/group.cc b/test/group/group.cc
index e82bed7..d04ff9b 100644
--- a/test/group/group.cc
+++ b/test/group/group.cc
@@ -1,14 +1,20 @@
 #include <thread>
+#include <algorithm>
 #include "md5.h"
 #include "group.h"
 #include "gtest/gtest.h"
 
+#include "group/size.h"
+
 using klotski::Group;
 using klotski::AllCases;
 using klotski::CommonCode;
 
 using klotski::TYPE_ID_LIMIT;
 using klotski::ALL_CASES_SIZE_SUM;
+using klotski::GROUP_ALL_CASES_SIZE;
+
+using klotski::TYPE_ID_LIMIT;
 
 const char BLOCK_NUM_MD5[] = "46a7b3af6d039cbe2f7eaebdd196c6a2";
 
@@ -62,10 +68,26 @@ TEST(Group, block_num) {
 }
 
 TEST(Group, all_cases) {
+    std::vector<std::vector<CommonCode>> all_cases;
+    for (uint32_t type_id = 0; type_id < TYPE_ID_LIMIT; ++type_id) {
+        all_cases.emplace_back(Group::all_cases(type_id)); // build test data
+    }
 
-    // TODO: all_cases number
-    // TODO: combine test
-    // TODO: data order
-    // TODO: test every cases (type_id)
+    std::vector<uint64_t> combine_cases;
+    combine_cases.reserve(ALL_CASES_SIZE_SUM);
+    for (uint32_t id = 0; id < TYPE_ID_LIMIT; ++id) {
+        EXPECT_EQ(all_cases[id].size(), GROUP_ALL_CASES_SIZE[id]); // verify cases number
+        for (auto &&common_code : all_cases[id]) {
+            EXPECT_EQ(Group::type_id(common_code), id); // verify type id
+            combine_cases.emplace_back(common_code.unwrap());
+        }
+        std::is_sorted(all_cases[id].begin(), all_cases[id].end()); // verify data order
+    }
+    EXPECT_EQ(combine_cases.size(), ALL_CASES_SIZE_SUM); // verify sum
 
+    auto all_cases_release = AllCases::release();
+    std::stable_sort(combine_cases.begin(), combine_cases.end());
+    for (uint32_t i = 0; i < combine_cases.size(); ++i) {
+        EXPECT_EQ(combine_cases[i], all_cases_release[i]); // verify after combined
+    }
 }