diff --git a/test/ffi/codec.cc b/test/ffi/codec.cc
index 94a653d..7a5b9d3 100644
--- a/test/ffi/codec.cc
+++ b/test/ffi/codec.cc
@@ -18,14 +18,17 @@ const static uint32_t TEST_SHORT_CODE_ERR = 29670987;
 const static uint64_t TEST_COMMON_CODE_ERR = 0x1'2190'2300;
 const static uint64_t TEST_RAW_CODE_ERR = 0x0A34'182B'3810'2D21;
 
+const static char TEST_SHORT_CODE_STR_ERR[] = "R50EH";
+const static char TEST_COMMON_CODE_STR_ERR[] = "123J432A9";
+
 TEST(FFI, codec_warm_up) {
-    // short code normal mode check
+    /// short code normal mode check
     EXPECT_EQ(is_short_code_available(), BasicRanges::status() == BasicRanges::AVAILABLE);
     short_code_enable();
     EXPECT_EQ(is_short_code_available(), true);
     EXPECT_EQ(is_short_code_available(), BasicRanges::status() == BasicRanges::AVAILABLE);
 
-    // short code fast mode check
+    /// short code fast mode check
     EXPECT_EQ(is_short_code_available_fast(), AllCases::status() == AllCases::AVAILABLE);
     short_code_enable_fast();
     EXPECT_EQ(is_short_code_available_fast(), true);
@@ -42,3 +45,32 @@ TEST(FFI, codec_checker) {
     EXPECT_EQ(common_code_check(TEST_COMMON_CODE_OK), true);
     EXPECT_NE(common_code_check(TEST_COMMON_CODE_ERR), true);
 }
+
+TEST(FFI, codec_string) {
+    EXPECT_EQ(SHORT_CODE_STR_SIZE, 6);
+    EXPECT_EQ(COMMON_CODE_STR_SIZE, 10);
+
+    /// short code string verify
+    uint32_t short_code;
+    char short_code_buffer[SHORT_CODE_STR_SIZE];
+    EXPECT_EQ(short_code_to_string(TEST_SHORT_CODE_ERR, short_code_buffer), false);
+    EXPECT_EQ(short_code_from_string(TEST_SHORT_CODE_STR_ERR, &short_code), false);
+
+    EXPECT_EQ(short_code_to_string(TEST_SHORT_CODE_OK, short_code_buffer), true);
+    EXPECT_EQ(short_code_from_string(short_code_buffer, &short_code), true);
+    EXPECT_EQ(short_code, TEST_SHORT_CODE_OK);
+
+    /// common code string verify
+    uint64_t common_code;
+    char common_code_buffer[COMMON_CODE_STR_SIZE];
+    EXPECT_EQ(common_code_to_string(TEST_COMMON_CODE_ERR, common_code_buffer), false);
+    EXPECT_EQ(common_code_from_string(TEST_COMMON_CODE_STR_ERR, &common_code), false);
+
+    EXPECT_EQ(common_code_to_string(TEST_COMMON_CODE_OK, common_code_buffer), true);
+    EXPECT_EQ(common_code_from_string(common_code_buffer, &common_code), true);
+    EXPECT_EQ(common_code, TEST_COMMON_CODE_OK);
+
+    EXPECT_EQ(common_code_to_string_shorten(TEST_COMMON_CODE_OK, common_code_buffer), true);
+    EXPECT_EQ(common_code_from_string(common_code_buffer, &common_code), true);
+    EXPECT_EQ(common_code, TEST_COMMON_CODE_OK);
+}