Fix interface conversion when Kind() == string but v.(string) panics

redactrus.go

@@ -1,6 +1,7 @@
 package redactrus
 
 import (
+	"fmt"
 	"reflect"
 	"regexp"
 
@@ -56,9 +57,20 @@ func (h *Hook) Fire(e *logrus.Entry) error {
 			}
 
 			// Redact based on value matching in Data fields
+			// Handle fmt.Stringer type
+			if vv, ok := v.(fmt.Stringer); ok {
+				e.Data[k] = re.ReplaceAllString(vv.String(), "$1[REDACTED]$2")
+				continue
+			}
+
 			switch reflect.TypeOf(v).Kind() {
 			case reflect.String:
-				e.Data[k] = re.ReplaceAllString(v.(string), "$1[REDACTED]$2")
+				switch vv := v.(type) {
+				case string:
+					e.Data[k] = re.ReplaceAllString(vv, "$1[REDACTED]$2")
+				default:
+					e.Data[k] = re.ReplaceAllString(fmt.Sprint(v), "$1[REDACTED]$2")
+				}
 				continue
 			}
 		}

redactrus_test.go

@@ -151,3 +151,36 @@ func TestNilField(t *testing.T) {
 	assert.Nil(t, err)
 	assert.Equal(t, logrus.Fields{"Nil": nil}, logEntry.Data)
 }
+
+type stringerValue struct {
+	value string
+}
+
+func (v stringerValue) String() string {
+	return v.value
+}
+
+func TestStringer(t *testing.T) {
+	logEntry := &logrus.Entry{
+		Data: logrus.Fields{"Stringer": stringerValue{"kind is fmt.Stringer"}},
+	}
+	h = &Hook{RedactionList: []string{"kind"}}
+	err := h.Fire(logEntry)
+
+	assert.Nil(t, err)
+	assert.Equal(t, logrus.Fields{"Stringer": "[REDACTED] is fmt.Stringer"}, logEntry.Data)
+}
+
+type TypedString string
+
+// Logrus fields can have re-typed strings so test we handle this edge case
+func TestTypedStringValue(t *testing.T) {
+	logEntry := &logrus.Entry{
+		Data: logrus.Fields{"TypedString": TypedString("kind is string")},
+	}
+	h = &Hook{RedactionList: []string{"kind"}}
+	err := h.Fire(logEntry)
+
+	assert.Nil(t, err)
+	assert.Equal(t, logrus.Fields{"TypedString": "[REDACTED] is string"}, logEntry.Data)
+}