Quote non-string values if necessary

text_formatter.go

@@ -184,7 +184,12 @@ func (f *TextFormatter) appendValue(b *bytes.Buffer, value interface{}) {
 			b.WriteString(f.quoteString(errmsg))
 		}
 	default:
-		fmt.Fprint(b, value)
+		s := fmt.Sprint(value)
+		if !f.needsQuoting(s) {
+			b.WriteString(s)
+		} else {
+			b.WriteString(f.quoteString(s))
+		}
 	}
 }
 

text_formatter_test.go

@@ -6,6 +6,7 @@ import (
 	"strings"
 	"testing"
 	"time"
+	"fmt"
 )
 
 func TestQuoting(t *testing.T) {
@@ -83,6 +84,16 @@ func TestEscaping_DefaultQuoteCharacter(t *testing.T) {
 	}
 }
 
+func TestEscaping_Time(t *testing.T) {
+	tf := &TextFormatter{DisableColors: true}
+	ts := time.Now()
+
+	b, _ := tf.Format(WithField("test", ts))
+	if !bytes.Contains(b, []byte(fmt.Sprintf("\"%s\"", ts.Format("2006-01-02 15:04:05.999999999 -0700 MST")))) {
+		t.Errorf("escaping expected for %q (result was %q)", ts, string(b))
+	}
+}
+
 func TestEscaping_CustomQuoteCharacter(t *testing.T) {
 	tf := &TextFormatter{DisableColors: true}