diff --git a/src/rust_ffi/src/codec/common_code.rs b/src/rust_ffi/src/codec/common_code.rs
index 9d411d7..a6d0765 100644
--- a/src/rust_ffi/src/codec/common_code.rs
+++ b/src/rust_ffi/src/codec/common_code.rs
@@ -228,3 +228,13 @@ impl CommonCode {
         )
     }
 }
+
+#[cfg(test)]
+mod tests {
+    const TEST_CODE: u64 = 0x1_A9BF_0C00;
+    const TEST_CODE_STR: &str = "1A9BF0C00";
+    const TEST_CODE_STR_SHR: &str = "1A9BF0C";
+
+    const TEST_CODE_ERR: u64 = 0x1_A9BF_FC00;
+    const TEST_CODE_STR_ERR: &str = "123J432A9";
+}
diff --git a/src/rust_ffi/src/codec/raw_code.rs b/src/rust_ffi/src/codec/raw_code.rs
index 819fc14..5ad0724 100644
--- a/src/rust_ffi/src/codec/raw_code.rs
+++ b/src/rust_ffi/src/codec/raw_code.rs
@@ -313,3 +313,9 @@ impl RawCode {
         )
     }
 }
+
+#[cfg(test)]
+mod tests {
+    const TEST_CODE: u64 = 0x0_603_EDF_5CA_FFF_5E2;
+    const TEST_CODE_ERR: u64 = 0x0_A34_182_B38_102_D21;
+}
diff --git a/src/rust_ffi/src/codec/short_code.rs b/src/rust_ffi/src/codec/short_code.rs
index 203b309..eeeef12 100644
--- a/src/rust_ffi/src/codec/short_code.rs
+++ b/src/rust_ffi/src/codec/short_code.rs
@@ -258,3 +258,12 @@ impl ShortCode {
         codec_ffi::short_code_enable_fast();
     }
 }
+
+#[cfg(test)]
+mod tests {
+    const TEST_CODE: u32 = 4091296;
+    const TEST_CODE_STR: &str = "4WVE1";
+
+    const TEST_CODE_ERR: u32 = 29670987;
+    const TEST_CODE_STR_ERR: &str = "R50EH";
+}