From c5b1037a5973b1d2977486254ce286fb77ea3db6 Mon Sep 17 00:00:00 2001
From: Russ Egan <russellegan@gmail.com>
Date: Thu, 3 Oct 2019 13:38:30 -0500
Subject: [PATCH] =?UTF-8?q?when=20passing=20a=20single,=20bare=20value=20t?=
 =?UTF-8?q?o=20logger=20functions=E2=80=A6?=
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if the bare value is an error, use the key “error”
---
 core.go      |  6 ++++--
 core_test.go | 22 ++++++++++++++++++++++
 2 files changed, 26 insertions(+), 2 deletions(-)
 create mode 100644 core_test.go

diff --git a/core.go b/core.go
index df2a7e2..52e3fc5 100644
--- a/core.go
+++ b/core.go
@@ -132,8 +132,10 @@ func (l *Core) sweetenFields(args []interface{}) []zap.Field {
 		if len(args) == 1 {
 			// passed a bare arg with no key.  We'll handle this
 			// as a special case
-			fields = append(fields, zap.Any("", args[0]))
-			return fields
+			if err, ok := args[0].(error); ok {
+				return append(fields, zap.Error(err))
+			}
+			return append(fields, zap.Any("", args[0]))
 		}
 
 		// Make sure this element isn't a dangling key.
diff --git a/core_test.go b/core_test.go
new file mode 100644
index 0000000..6bbd3ab
--- /dev/null
+++ b/core_test.go
@@ -0,0 +1,22 @@
+package flume
+
+import (
+	"errors"
+	"github.com/stretchr/testify/assert"
+	"go.uber.org/zap"
+	"testing"
+)
+
+func TestSweetenFields(t *testing.T) {
+
+	// single value, instead of key/value pairs
+	c := NewCore("asdf")
+	fields := c.sweetenFields([]interface{}{1})
+
+	assert.Equal(t, []zap.Field{zap.Int("", 1)}, fields)
+
+	// if the bare value is an error, use the key "error"
+	err := errors.New("blue")
+	fields = c.sweetenFields([]interface{}{err})
+	assert.Equal(t, []zap.Field{zap.NamedError("error", err)}, fields)
+}