feat: display error stack when using .Fields() (#560)

context.go

@@ -23,7 +23,7 @@ func (c Context) Logger() Logger {
 // Only map[string]interface{} and []interface{} are accepted. []interface{} must
 // alternate string keys and arbitrary values, and extraneous ones are ignored.
 func (c Context) Fields(fields interface{}) Context {
- c.l.context = appendFields(c.l.context, fields)
+ c.l.context = appendFields(c.l.context, fields, c.l.stack)
  return c
 }
 

event.go

@@ -164,7 +164,7 @@ func (e *Event) Fields(fields interface{}) *Event {
  if e == nil {
  return e
  }
- e.buf = appendFields(e.buf, fields)
+ e.buf = appendFields(e.buf, fields, e.stack)
  return e
 }
 

fields.go

@@ -12,13 +12,13 @@ func isNilValue(i interface{}) bool {
  return (*[2]uintptr)(unsafe.Pointer(&i))[1] == 0
 }
 
-func appendFields(dst []byte, fields interface{}) []byte {
+func appendFields(dst []byte, fields interface{}, stack bool) []byte {
  switch fields := fields.(type) {
  case []interface{}:
  if n := len(fields); n&0x1 == 1 { // odd number
  fields = fields[:n-1]
  }
- dst = appendFieldList(dst, fields)
+ dst = appendFieldList(dst, fields, stack)
  case map[string]interface{}:
  keys := make([]string, 0, len(fields))
  for key := range fields {
@@ -28,13 +28,13 @@ func appendFields(dst []byte, fields interface{}) []byte {
  kv := make([]interface{}, 2)
  for _, key := range keys {
  kv[0], kv[1] = key, fields[key]
- dst = appendFieldList(dst, kv)
+ dst = appendFieldList(dst, kv, stack)
  }
  }
  return dst
 }
 
-func appendFieldList(dst []byte, kvList []interface{}) []byte {
+func appendFieldList(dst []byte, kvList []interface{}, stack bool) []byte {
  for i, n := 0, len(kvList); i < n; i += 2 {
  key, val := kvList[i], kvList[i+1]
  if key, ok := key.(string); ok {
@@ -74,6 +74,21 @@ func appendFieldList(dst []byte, kvList []interface{}) []byte {
  default:
  dst = enc.AppendInterface(dst, m)
  }
+
+ if stack && ErrorStackMarshaler != nil {
+ dst = enc.AppendKey(dst, ErrorStackFieldName)
+ switch m := ErrorStackMarshaler(val).(type) {
+ case nil:
+ case error:
+ if m != nil && !isNilValue(m) {
+ dst = enc.AppendString(dst, m.Error())
+ }
+ case string:
+ dst = enc.AppendString(dst, m)
+ default:
+ dst = enc.AppendInterface(dst, m)
+ }
+ }
  case []error:
  dst = enc.AppendArrayStart(dst)
  for i, err := range val {

pkgerrors/stacktrace_test.go

@@ -28,6 +28,22 @@ func TestLogStack(t *testing.T) {
  }
 }
 
+func TestLogStackFields(t *testing.T) {
+ zerolog.ErrorStackMarshaler = MarshalStack
+
+ out := &bytes.Buffer{}
+ log := zerolog.New(out)
+
+ err := fmt.Errorf("from error: %w", errors.New("error message"))
+ log.Log().Stack().Fields([]interface{}{"error", err}).Msg("")
+
+ got := out.String()
+ want := `\{"error":"from error: error message","stack":\[\{"func":"TestLogStackFields","line":"37","source":"stacktrace_test.go"\},.*\]\}\n`
+ if ok, _ := regexp.MatchString(want, got); !ok {
+ t.Errorf("invalid log output:\ngot: %v\nwant: %v", got, want)
+ }
+}
+
 func TestLogStackFromContext(t *testing.T) {
  zerolog.ErrorStackMarshaler = MarshalStack
 
@@ -38,7 +54,7 @@ func TestLogStackFromContext(t *testing.T) {
  log.Log().Err(err).Msg("") // not explicitly calling Stack()
 
  got := out.String()
- want := `\{"stack":\[\{"func":"TestLogStackFromContext","line":"37","source":"stacktrace_test.go"\},.*\],"error":"from error: error message"\}\n`
+ want := `\{"stack":\[\{"func":"TestLogStackFromContext","line":"53","source":"stacktrace_test.go"\},.*\],"error":"from error: error message"\}\n`
  if ok, _ := regexp.MatchString(want, got); !ok {
  t.Errorf("invalid log output:\ngot: %v\nwant: %v", got, want)
  }