Add reason string to InvalidTxData error. (#137)

There are several different places where `Error::InvalidTxData` can be
produced; this adds a `String` value to it so that every place that
results in this error can also provide a helpful explanation.

src/database.rs

@@ -596,7 +596,7 @@ impl Database {
 
         let mut i: usize = 0;
         for t in txs.iter() {
-            let tx = Tx::try_from(t.as_slice()).map_err(|_| Error::InvalidTxData)?;
+            let tx = Tx::try_from(t.as_slice()).map_err(|e| Error::InvalidTxData(e.to_string()))?;
 
             let mut code = Default::default();
             let mut txid_wrapper: Vec<u8> = vec![];
@@ -642,7 +642,7 @@ impl Database {
                     .get_section(tx.code_sechash())
                     .and_then(|s| s.code_sec())
                     .map(|s| s.code.hash().0)
-                    .ok_or(Error::InvalidTxData)?;
+                    .ok_or(Error::InvalidTxData("no code hash".into()))?;
 
                 let code_hex = hex::encode(code.as_slice());
                 let unknown_type = "unknown".to_string();
@@ -653,7 +653,9 @@ impl Database {
                 // decode tx_transfer, tx_bond and tx_unbound to store the decoded data in their tables
                 // if the transaction has failed don't try to decode because the changes are not included and the data might not be correct
                 if return_code.unwrap() == 0 {
-                    let data = tx.data().ok_or(Error::InvalidTxData)?;
+                    let data = tx
+                        .data()
+                        .ok_or(Error::InvalidTxData("tx has no data".into()))?;
 
                     match type_tx.as_str() {
                         "tx_transfer" => {

src/error.rs

@@ -18,8 +18,8 @@ use tokio::sync::mpsc::error::SendError;
 pub enum Error {
     #[error("Invalid Block data")]
     InvalidBlockData,
-    #[error("Invalid Transaction data")]
-    InvalidTxData,
+    #[error("Invalid Transaction data (reason: {0})")]
+    InvalidTxData(String),
     #[error("Tendermint error: {0}")]
     TendermintError(#[from] TError),
     #[error("Tendermint rpc_error: {0}")]
@@ -71,7 +71,7 @@ impl IntoResponse for Error {
     fn into_response(self) -> Response {
         let status = match self {
             Error::InvalidBlockData => StatusCode::EXPECTATION_FAILED,
-            Error::InvalidTxData => StatusCode::EXPECTATION_FAILED,
+            Error::InvalidTxData(_) => StatusCode::EXPECTATION_FAILED,
             Error::DB(_) => StatusCode::NOT_FOUND,
             Error::HexError(_) => StatusCode::BAD_REQUEST,
             Error::TendermintError(_) => StatusCode::EXPECTATION_FAILED,

src/server/tx.rs

@@ -113,7 +113,7 @@ impl TxInfo {
     pub fn decode_tx(&mut self, checksums: &HashMap<String, String>) -> Result<(), Error> {
         if self.is_decrypted() {
             let Some(type_tx) = checksums.get(&self.code()) else {
-                return Err(Error::InvalidTxData);
+                return Err(Error::InvalidTxData("failed to get checksum".into()));
             };
 
             let decoded = match type_tx.as_str() {
@@ -152,19 +152,22 @@ impl TxInfo {
                     PendingTransfer::try_from_slice(&self.data()).map(TxDecoded::EthPoolBridge)?
                 }
                 _ => {
-                    return Err(Error::InvalidTxData);
+                    return Err(Error::InvalidTxData(format!(
+                        "unsupported type_tx {}",
+                        type_tx
+                    )));
                 }
             };
 
             self.set_tx(decoded);
 
             return Ok(());
         }
-        Err(Error::InvalidTxData)
+        Err(Error::InvalidTxData("tx is not decrypted".into()))
     }
 
     fn decode_ibc(tx_data: &[u8]) -> Result<IbcTx, Error> {
-        let msg = Any::decode(tx_data).map_err(|_| Error::InvalidTxData)?;
+        let msg = Any::decode(tx_data).map_err(|e| Error::InvalidTxData(e.to_string()))?;
         if msg.type_url.as_str() == MSG_TRANSFER_TYPE_URL
             && MsgTransfer::try_from(msg.clone()).is_ok()
         {