Merge pull request #508 from dunglas/fix/logging-error-handling

fix: improve logging errors

docs/hub/debug.md

@@ -1,7 +1,7 @@
 # Debug the Mercure.rocks Hub
 
 The hub is shipped with [`pprof`](https://blog.golang.org/pprof),
-a profiler allowing to find bottlenecks, memory leaks and blocked goroutines 
+a profiler allowing to find bottlenecks, memory leaks and blocked goroutines
 among other things.
 
 To enable the profiler, add the `debug` global directive to your `Caddyfile`:
@@ -19,14 +19,16 @@ You can use [the `pprof` tool](https://golang.org/pkg/net/http/pprof/) to visual
 
 ## Examples
 
-Tip: type `web` when in interative mode to display a visual representation of the profile. 
-
 Look at the heap profile:
 
-   go tool pprof http://localhost:2019/debug/pprof/heap
+```console
+go tool pprof -http=:8080 http://localhost:2019/debug/pprof/heap
+```
 
 Look at the past memory allocations:
 
-    go tool pprof http://localhost:2019/debug/pprof/allocs
+```console
+go tool pprof -http=:8080 http://localhost:2019/debug/pprof/allocs
+```
 
 See `http://localhost:2019/debug/pprof/` for the list of available data.

log.go

@@ -2,6 +2,8 @@ package mercure
 
 import "go.uber.org/zap/zapcore"
 
+// stringArray has been copied from https://github.com/uber-go/zap/blob/master/array.go#L250-L257
+// Copyright (c) 2016 Uber Technologies, Inc.
 type stringArray []string
 
 func (ss stringArray) MarshalLogArray(arr zapcore.ArrayEncoder) error {

subscriber.go

@@ -1,6 +1,7 @@
 package mercure
 
 import (
+	"fmt"
 	"net/url"
 	"sync"
 
@@ -229,10 +230,14 @@ func (s *Subscriber) MarshalLogObject(enc zapcore.ObjectEncoder) error {
 		enc.AddString("remote_addr", s.RemoteAddr)
 	}
 	if s.TopicSelectors != nil {
-		enc.AddArray("topic_selectors", stringArray(s.TopicSelectors))
+		if err := enc.AddArray("topic_selectors", stringArray(s.TopicSelectors)); err != nil {
+			return fmt.Errorf("log error: %w", err)
+		}
 	}
 	if s.Topics != nil {
-		enc.AddArray("topics", stringArray(s.Topics))
+		if err := enc.AddArray("topics", stringArray(s.Topics)); err != nil {
+			return fmt.Errorf("log error: %w", err)
+		}
 	}
 
 	return nil

update.go

@@ -1,6 +1,8 @@
 package mercure
 
 import (
+	"fmt"
+
 	"github.com/gofrs/uuid"
 	"go.uber.org/zap/zapcore"
 )
@@ -25,7 +27,9 @@ func (u *Update) MarshalLogObject(enc zapcore.ObjectEncoder) error {
 	enc.AddString("id", u.ID)
 	enc.AddString("type", u.Type)
 	enc.AddUint64("retry", u.Retry)
-	enc.AddArray("topics", stringArray(u.Topics))
+	if err := enc.AddArray("topics", stringArray(u.Topics)); err != nil {
+		return fmt.Errorf("log error: %w", err)
+	}
 	enc.AddBool("private", u.Private)
 
 	if u.Debug {