Logs don't panic when receiving a `nil` *time.Time

log/log.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"net/http"
 	"os"
+	"reflect"
 	"runtime"
 	"sort"
 	"strings"
@@ -267,7 +268,12 @@ func addFields(logger *logrus.Entry, keyValuePairs []interface{}) *logrus.Entry
 				case time.Duration:
 					logger = logger.WithField(name, ShortDur(v))
 				case fmt.Stringer:
-					logger = logger.WithField(name, v.String())
+					vOf := reflect.ValueOf(v)
+					if vOf.Kind() == reflect.Pointer && vOf.IsNil() {
+						logger = logger.WithField(name, "nil")
+					} else {
+						logger = logger.WithField(name, v.String())
+					}
 				default:
 					logger = logger.WithField(name, v)
 				}

log/log_test.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"net/http/httptest"
 	"testing"
+	"time"
 
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
@@ -91,9 +92,20 @@ var _ = Describe("Logger", func() {
 			SetLogSourceLine(true)
 			Error("A crash happened")
 			// NOTE: This assertion breaks if the line number above changes
-			Expect(hook.LastEntry().Data[" source"]).To(ContainSubstring("/log/log_test.go:92"))
+			Expect(hook.LastEntry().Data[" source"]).To(ContainSubstring("/log/log_test.go:93"))
 			Expect(hook.LastEntry().Message).To(Equal("A crash happened"))
 		})
+
+		It("logs fmt.Stringer as a string", func() {
+			t := time.Now()
+			Error("Simple Message", "key1", t)
+			Expect(hook.LastEntry().Data["key1"]).To(Equal(t.String()))
+		})
+		It("logs nil fmt.Stringer as nil", func() {
+			var t *time.Time
+			Error("Simple Message", "key1", t)
+			Expect(hook.LastEntry().Data["key1"]).To(Equal("nil"))
+		})
 	})
 
 	Describe("Levels", func() {