Fix parsing of electrum error response

daemon/src/wallet.rs

@@ -1,5 +1,5 @@
 use crate::model::WalletInfo;
-use anyhow::{anyhow, bail, Context, Result};
+use anyhow::{anyhow, Context, Result};
 use bdk::bitcoin::util::bip32::ExtendedPrivKey;
 use bdk::bitcoin::util::psbt::PartiallySignedTransaction;
 use bdk::bitcoin::{Amount, PublicKey, Transaction, Txid};
@@ -124,27 +124,22 @@ impl Wallet {
     }
 }
 
-fn parse_rpc_protocol_error_code(error_value: &Value) -> anyhow::Result<i64> {
-    let json_map = match error_value {
-        serde_json::Value::Object(map) => map,
-        _ => bail!("Json error is not json object "),
-    };
-
-    let error_code_value = match json_map.get("code") {
-        Some(val) => val,
-        None => bail!("No error code field"),
-    };
-
-    let error_code_number = match error_code_value {
-        serde_json::Value::Number(num) => num,
-        _ => bail!("Error code is not a number"),
-    };
-
-    if let Some(int) = error_code_number.as_i64() {
-        Ok(int)
-    } else {
-        bail!("Error code is not an unsigned integer")
-    }
+fn parse_rpc_protocol_error_code(error_value: &Value) -> Result<i64> {
+    let json = error_value
+        .as_str()
+        .context("Not a string")?
+        .split_terminator("RPC error: ")
+        .nth(1)
+        .context("Unknown error code format")?;
+
+    let error = serde_json::from_str::<RpcError>(json).context("Error has unexpected format")?;
+
+    Ok(error.code)
+}
+
+#[derive(serde::Deserialize)]
+struct RpcError {
+    code: i64,
 }
 
 /// Bitcoin error codes: https://github.com/bitcoin/bitcoin/blob/97d3500601c1d28642347d014a6de1e38f53ae4e/src/rpc/protocol.h#L23
@@ -160,3 +155,17 @@ impl From<RpcErrorCode> for i64 {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn parse_error_response() {
+        let response = serde_json::Value::String(r#"sendrawtransaction RPC error: {"code":-27,"message":"Transaction already in block chain"}"#.to_owned());
+
+        let code = parse_rpc_protocol_error_code(&response).unwrap();
+
+        assert_eq!(code, -27);
+    }
+}