add hash encode/decode test

src/hash.rs

@@ -86,3 +86,20 @@ pub fn decode<T: AsRef<str>>(string: T) -> Result<Vec<u8>> {
         Ok(bs58::decode(data).into_vec()?)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::hash::{decode, encode};
+
+    #[test]
+    fn test_encode_decode() {
+        let content = "Hello, World!".as_bytes();
+
+        let encoded = encode(content);
+        let decoded = decode(encoded);
+
+        assert!(decoded.is_ok());
+
+        assert_eq!(content, decoded.unwrap());
+    }
+}