From 8bc9fa951faedf83f2ee18c0b47794da1197ceea Mon Sep 17 00:00:00 2001
From: michael1011 <me@michael1011.at>
Date: Thu, 2 Jan 2025 17:57:05 +0100
Subject: [PATCH] chore: nicer CLN error parsing

---
 boltzr/src/lightning/cln/mod.rs | 50 ++++++++++++++++++++++++++++++++-
 1 file changed, 49 insertions(+), 1 deletion(-)

diff --git a/boltzr/src/lightning/cln/mod.rs b/boltzr/src/lightning/cln/mod.rs
index e149a499..c32d4f64 100644
--- a/boltzr/src/lightning/cln/mod.rs
+++ b/boltzr/src/lightning/cln/mod.rs
@@ -4,6 +4,7 @@ use crate::lightning::cln::cln_rpc::{
     ListconfigsResponse,
 };
 use alloy::hex;
+use anyhow::anyhow;
 use async_trait::async_trait;
 use serde::{Deserialize, Serialize};
 use std::fs;
@@ -76,7 +77,8 @@ impl Cln {
                 recurrence_label: None,
                 recurrence_counter: None,
             })
-            .await?;
+            .await
+            .map_err(Self::parse_error)?;
 
         Ok(res.into_inner().invoice)
     }
@@ -93,6 +95,34 @@ impl Cln {
             .await?;
         Ok(res.into_inner())
     }
+
+    fn parse_error(status: tonic::Status) -> anyhow::Error {
+        let mut msg = status.message();
+
+        const MESSAGE_PREFIXES: &[&str] = &["message: \"", "message\":\"", "message\\\":\\\""];
+        const MESSAGE_SUFFIXES: &[&str] = &["\", data:", "\\\"}", "\"}"];
+
+        'outer: loop {
+            for prefix in MESSAGE_PREFIXES {
+                if let Some(start) = msg.find(prefix) {
+                    for suffix in MESSAGE_SUFFIXES {
+                        if let Some(end) = msg.rfind(suffix) {
+                            msg = &msg[start + prefix.len()..end];
+                            continue 'outer;
+                        }
+                    }
+                }
+            }
+
+            break;
+        }
+
+        if msg.is_empty() {
+            return anyhow!("{}", status.code().to_string());
+        }
+
+        anyhow!(msg.to_owned())
+    }
 }
 
 #[async_trait]
@@ -137,3 +167,21 @@ impl BaseClient for Cln {
         Ok(())
     }
 }
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use rstest::*;
+
+    #[rstest]
+    #[case("Error calling method Xpay: RpcError { code: Some(203), message: \"Destination said it doesn't know invoice: incorrect_or_unknown_payment_details\", data: None }", "Destination said it doesn't know invoice: incorrect_or_unknown_payment_details")]
+    #[case("Failed: could not route or connect directly to 02ead25af6e0271c5167d6fd05545d2d538995ce3e16ad780a1010fc4e91522202: {\"code\":400,\"message\":\"Unable to connect, no address known for peer\"}", "Unable to connect, no address known for peer")]
+    #[case("Error calling method FetchInvoice: RpcError { code: Some(1003), message: \"Failed: could not route or connect directly to 02ee337aec2b12fef609a57d1c32834fe3107d315acaf8f5206ccf94dc2a9baa8c: {\"code\":400,\"message\":\"Unable to connect, no address known for peer\"}\", data: None }", "Unable to connect, no address known for peer")]
+    #[case("Error calling method FetchInvoice: RpcError { code: Some(1003), message: \"Failed: could not route or connect directly to 02ee337aec2b12fef609a57d1c32834fe3107d315acaf8f5206ccf94dc2a9baa8c: {\\\"code\\\":400,\\\"message\\\":\\\"Unable to connect, no address known for peer\\\"}\", data: None }", "Unable to connect, no address known for peer")]
+    #[case("gRPC error", "gRPC error")]
+    #[case("", "The operation was cancelled")]
+    fn test_parse_error(#[case] msg: &str, #[case] expected: &str) {
+        let error = Cln::parse_error(tonic::Status::new(tonic::Code::Cancelled, msg));
+        assert_eq!(error.to_string(), expected);
+    }
+}