diff --git a/light-client-db-common/src/lib.rs b/light-client-db-common/src/lib.rs
index 69ef4abf..82752ff2 100644
--- a/light-client-db-common/src/lib.rs
+++ b/light-client-db-common/src/lib.rs
@@ -2,6 +2,10 @@ use anyhow::anyhow;
 use anyhow::Context;
 use serde::{de::DeserializeOwned, Deserialize, Serialize};
 use web_sys::js_sys::{Atomics, Int32Array, Uint8Array};
+
+#[cfg(test)]
+pub mod tests;
+
 #[derive(Serialize, Deserialize, Debug)]
 /// Represent a key-value pair
 pub struct KV {
diff --git a/light-client-db-common/src/tests.rs b/light-client-db-common/src/tests.rs
new file mode 100644
index 00000000..86362598
--- /dev/null
+++ b/light-client-db-common/src/tests.rs
@@ -0,0 +1,33 @@
+use wasm_bindgen_test::wasm_bindgen_test;
+use web_sys::js_sys::{Int32Array, SharedArrayBuffer, Uint8Array};
+
+use crate::{write_command_with_payload, InputCommand, OutputCommand};
+
+#[wasm_bindgen_test]
+fn test_command_conversion() {
+    assert_eq!(InputCommand::DbRequest as i32, 2);
+    assert_eq!(OutputCommand::DbResponse as i32, 2);
+    assert!(InputCommand::try_from(20 as i32).is_ok());
+    assert!(OutputCommand::try_from(20 as i32).is_ok());
+}
+
+#[wasm_bindgen_test]
+// #[test]
+fn test_command_write() {
+    let arr_buf = SharedArrayBuffer::new(100);
+    let i32arr = Int32Array::new(&arr_buf);
+    let u8arr = Uint8Array::new(&arr_buf);
+    write_command_with_payload(
+        InputCommand::DbRequest as i32,
+        vec![1, 2, 3, 4],
+        &i32arr,
+        &u8arr,
+    )
+    .unwrap();
+    assert_eq!(i32arr.get_index(0), InputCommand::DbRequest as i32);
+    let mut buf = vec![0u8; 100];
+    u8arr.copy_to(&mut buf);
+    let result =
+        bincode::deserialize::<Vec<i32>>(&buf[8..i32arr.get_index(1) as usize + 8]).unwrap();
+    assert_eq!(result, vec![1, 2, 3, 4]);
+}