From 833bbd9e7f96c16288d1fa27aadf8817384db05b Mon Sep 17 00:00:00 2001
From: Piotr Grabowski <avelanarius@gmail.com>
Date: Thu, 18 Jul 2024 14:46:49 +0200
Subject: [PATCH] Print more error details in LogAndHandlePanic (#542)

Before this change, panics handled by `LogAndHandlePanic` were logged to
the Quesma UI with only the stack trace - without any details about the
error itself (for example without
`runtime error: comparing uncomparable type []string`). This made
debugging panics harder.

This commit adds the error information from `commonRecovery` also to
`LogAndHandlePanic`.

Before:
```
quesma request failed: panic recovered goroutine 3436 [running]:
runtime/debug.Stack() /Users/piotrgrabowski/sdk/go1.23rc1/src/runtime/debug/stack.go:26
+0x64 quesma/quesma/recovery.LogAndHandlePanic({0x1011f2510, 0x14004aaac90}
...
```

After:
<pre>
quesma request failed: Panic recovered: <b>runtime error: comparing
uncomparable type []string</b>
goroutine 3027 [running]: runtime/debug.Stack()
/Users/piotrgrabowski/sdk/go1.23rc1/src/runtime/debug/stack.go:26
+0x64 quesma/quesma/recovery.LogAndHandlePanic({0x102b0a510,
0x14003944330}
...
</pre>

Co-authored-by: Jacek Migdal <jacek@quesma.com>
---
 quesma/quesma/recovery/recovery_strategies.go | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/quesma/quesma/recovery/recovery_strategies.go b/quesma/quesma/recovery/recovery_strategies.go
index 00cea1fca..955d2ea31 100644
--- a/quesma/quesma/recovery/recovery_strategies.go
+++ b/quesma/quesma/recovery/recovery_strategies.go
@@ -16,18 +16,20 @@ import (
 // make the recovery simple as possible.
 var PanicCounter atomic.Int64
 
-func commonRecovery(r any, panicLogger func() *zerolog.Event) {
-	PanicCounter.Add(1)
-	var err error
+func recoveredToError(r any) error {
 	switch t := r.(type) {
 	case string:
-		err = errors.New(t)
+		return errors.New(t)
 	case error:
-		err = t
+		return t
 	default:
-		err = errors.New("unknown error")
+		return errors.New("unknown error")
 	}
-	panicLogger().Msgf("Panic recovered: %s\n%s", err, string(debug.Stack()))
+}
+
+func commonRecovery(r any, panicLogger func() *zerolog.Event) {
+	PanicCounter.Add(1)
+	panicLogger().Msgf("Panic recovered: %s\n%s", recoveredToError(r), string(debug.Stack()))
 }
 
 func LogPanic() {
@@ -49,6 +51,6 @@ func LogAndHandlePanic(ctx context.Context, cleanupHandler func(err error)) {
 		commonRecovery(r, func() *zerolog.Event {
 			return logger.ErrorWithCtx(ctx)
 		})
-		cleanupHandler(errors.New("panic recovered " + string(debug.Stack())))
+		cleanupHandler(errors.New("Panic recovered: " + recoveredToError(r).Error() + "\n" + string(debug.Stack())))
 	}
 }