chore: minor improvements

otelx/attribute.go

@@ -10,6 +10,8 @@ import (
  "go.opentelemetry.io/otel/attribute"
 )
 
+const nullString = "<null>"
+
 func StringAttrs(attrs map[string]string) []attribute.KeyValue {
  s := []attribute.KeyValue{}
  for k, v := range attrs {
@@ -27,16 +29,17 @@ func Nullable[V any, VN *V | sql.Null[V], A func(string, V) attribute.KeyValue](
  switch v := any(v).(type) {
  case *V:
  if v == nil {
- return attribute.String(k, "<nil>")
+ return attribute.String(k, nullString)
  }
  return a(k, *v)
  case sql.Null[V]:
  if !v.Valid {
- return attribute.String(k, "<nil>")
+ return attribute.String(k, nullString)
  }
  return a(k, v.V)
  }
- return attribute.String(k, "unsupported type")
+ // This should never happen, as the type switch above is exhaustive to the generic type VN.
+ return attribute.String(k, fmt.Sprintf("<got unsupported type %T>", v))
 }
 
 func NullString[V *string | sql.Null[string]](k string, v V) attribute.KeyValue {
@@ -45,7 +48,7 @@ func NullString[V *string | sql.Null[string]](k string, v V) attribute.KeyValue
 
 func NullStringer(k string, v fmt.Stringer) attribute.KeyValue {
  if v == nil {
- return attribute.String(k, "<nil>")
+ return attribute.String(k, nullString)
  }
  return attribute.String(k, v.String())
 }