Skip to content

Commit 369c1bd

Browse files
psrajatsywhangabhinav
authored
feat: support custom ReflectType encoder (#1039)
This adds support for overriding the mechanism we use to encode `ReflectType` fields. That is, in the following, log.Info("foo", zap.Reflect("bar", baz)) It allows `baz` to be serialized using a third-party JSON library by providing a custom ReflectedEncoder in the zapcore.EncoderConfig. `encoding/json`'s Encoder type is a valid ReflectedEncoder. Resolves #1034 Co-authored-by: Sung Yoon Whang <[email protected]> Co-authored-by: Abhinav Gupta <[email protected]>
1 parent 9367581 commit 369c1bd

5 files changed

+119
-7
lines changed

‎zapcore/encoder.go

+4
Original file line numberDiff line numberDiff line change
@@ -22,6 +22,7 @@ package zapcore
2222

2323
import (
2424
"encoding/json"
25+
"io"
2526
"time"
2627

2728
"go.uber.org/zap/buffer"
@@ -331,6 +332,9 @@ type EncoderConfig struct {
331332
// Unlike the other primitive type encoders, EncodeName is optional. The
332333
// zero value falls back to FullNameEncoder.
333334
EncodeName NameEncoder `json:"nameEncoder" yaml:"nameEncoder"`
335+
// Configure the encoder for interface{} type objects.
336+
// If not provided, objects are encoded using json.Encoder
337+
NewReflectedEncoder func(io.Writer) ReflectedEncoder `json:"-" yaml:"-"`
334338
// Configures the field separator used by the console encoder. Defaults
335339
// to tab.
336340
ConsoleSeparator string `json:"consoleSeparator" yaml:"consoleSeparator"`

‎zapcore/json_encoder.go

+7-6
Original file line numberDiff line numberDiff line change
@@ -22,7 +22,6 @@ package zapcore
2222

2323
import (
2424
"encoding/base64"
25-
"encoding/json"
2625
"math"
2726
"sync"
2827
"time"
@@ -64,7 +63,7 @@ type jsonEncoder struct {
6463

6564
// for encoding generic values by reflection
6665
reflectBuf *buffer.Buffer
67-
reflectEnc *json.Encoder
66+
reflectEnc ReflectedEncoder
6867
}
6968

7069
// NewJSONEncoder creates a fast, low-allocation JSON encoder. The encoder
@@ -88,6 +87,11 @@ func newJSONEncoder(cfg EncoderConfig, spaced bool) *jsonEncoder {
8887
cfg.LineEnding = DefaultLineEnding
8988
}
9089

90+
// If no EncoderConfig.NewReflectedEncoder is provided by the user, then use default
91+
if cfg.NewReflectedEncoder == nil {
92+
cfg.NewReflectedEncoder = defaultReflectedEncoder
93+
}
94+
9195
return &jsonEncoder{
9296
EncoderConfig: &cfg,
9397
buf: bufferpool.Get(),
@@ -152,10 +156,7 @@ func (enc *jsonEncoder) AddInt64(key string, val int64) {
152156
func (enc *jsonEncoder) resetReflectBuf() {
153157
if enc.reflectBuf == nil {
154158
enc.reflectBuf = bufferpool.Get()
155-
enc.reflectEnc = json.NewEncoder(enc.reflectBuf)
156-
157-
// For consistency with our custom JSON encoder.
158-
enc.reflectEnc.SetEscapeHTML(false)
159+
enc.reflectEnc = enc.NewReflectedEncoder(enc.reflectBuf)
159160
} else {
160161
enc.reflectBuf.Reset()
161162
}

‎zapcore/json_encoder_impl_test.go

+1-1
Original file line numberDiff line numberDiff line change
@@ -508,7 +508,7 @@ func assertJSON(t *testing.T, expected string, enc *jsonEncoder) {
508508
}
509509

510510
func assertOutput(t testing.TB, cfg EncoderConfig, expected string, f func(Encoder)) {
511-
enc := &jsonEncoder{buf: bufferpool.Get(), EncoderConfig: &cfg}
511+
enc := NewJSONEncoder(cfg).(*jsonEncoder)
512512
f(enc)
513513
assert.Equal(t, expected, enc.buf.String(), "Unexpected encoder output after adding.")
514514

‎zapcore/json_encoder_test.go

+66
Original file line numberDiff line numberDiff line change
@@ -21,6 +21,7 @@
2121
package zapcore_test
2222

2323
import (
24+
"io"
2425
"testing"
2526
"time"
2627

@@ -171,3 +172,68 @@ func TestJSONEmptyConfig(t *testing.T) {
171172
})
172173
}
173174
}
175+
176+
// Encodes any object into empty json '{}'
177+
type emptyReflectedEncoder struct {
178+
writer io.Writer
179+
}
180+
181+
func (enc *emptyReflectedEncoder) Encode(obj interface{}) error {
182+
_, err := enc.writer.Write([]byte("{}"))
183+
return err
184+
}
185+
186+
func TestJSONCustomReflectedEncoder(t *testing.T) {
187+
tests := []struct {
188+
name string
189+
field zapcore.Field
190+
expected string
191+
}{
192+
{
193+
name: "encode custom map object",
194+
field: zapcore.Field{
195+
Key: "data",
196+
Type: zapcore.ReflectType,
197+
Interface: map[string]interface{}{
198+
"foo": "hello",
199+
"bar": 1111,
200+
},
201+
},
202+
expected: `{"data":{}}`,
203+
},
204+
{
205+
name: "encode nil object",
206+
field: zapcore.Field{
207+
Key: "data",
208+
Type: zapcore.ReflectType,
209+
},
210+
expected: `{"data":null}`,
211+
},
212+
}
213+
214+
for _, tt := range tests {
215+
tt := tt
216+
t.Run(tt.name, func(t *testing.T) {
217+
t.Parallel()
218+
219+
enc := zapcore.NewJSONEncoder(zapcore.EncoderConfig{
220+
NewReflectedEncoder: func(writer io.Writer) zapcore.ReflectedEncoder {
221+
return &emptyReflectedEncoder{
222+
writer: writer,
223+
}
224+
},
225+
})
226+
227+
buf, err := enc.EncodeEntry(zapcore.Entry{
228+
Level: zapcore.DebugLevel,
229+
Time: time.Now(),
230+
LoggerName: "logger",
231+
Message: "things happened",
232+
}, []zapcore.Field{tt.field})
233+
if assert.NoError(t, err, "Unexpected JSON encoding error.") {
234+
assert.JSONEq(t, tt.expected, buf.String(), "Incorrect encoded JSON entry.")
235+
}
236+
buf.Free()
237+
})
238+
}
239+
}

‎zapcore/reflected_encoder.go

+41
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,41 @@
1+
// Copyright (c) 2016 Uber Technologies, Inc.
2+
//
3+
// Permission is hereby granted, free of charge, to any person obtaining a copy
4+
// of this software and associated documentation files (the "Software"), to deal
5+
// in the Software without restriction, including without limitation the rights
6+
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
7+
// copies of the Software, and to permit persons to whom the Software is
8+
// furnished to do so, subject to the following conditions:
9+
//
10+
// The above copyright notice and this permission notice shall be included in
11+
// all copies or substantial portions of the Software.
12+
//
13+
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14+
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15+
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
16+
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17+
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
18+
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
19+
// THE SOFTWARE.
20+
21+
package zapcore
22+
23+
import (
24+
"encoding/json"
25+
"io"
26+
)
27+
28+
// ReflectedEncoder serializes log fields that can't be serialized with Zap's
29+
// JSON encoder. These have the ReflectType field type.
30+
// Use EncoderConfig.NewReflectedEncoder to set this.
31+
type ReflectedEncoder interface {
32+
// Encode encodes and writes to the underlying data stream.
33+
Encode(interface{}) error
34+
}
35+
36+
func defaultReflectedEncoder(w io.Writer) ReflectedEncoder {
37+
enc := json.NewEncoder(w)
38+
// For consistency with our custom JSON encoder.
39+
enc.SetEscapeHTML(false)
40+
return enc
41+
}

0 commit comments

Comments
 (0)