Add RawJSON field type

context.go

@@ -79,6 +79,15 @@ func (c Context) Bytes(key string, val []byte) Context {
 	return c
 }
 
+// RawJSON adds already encoded JSON to context.
+//
+// No sanity check is performed on b; it must not contain carriage returns and
+// be valid JSON.
+func (c Context) RawJSON(key string, b []byte) Context {
+	c.l.context = append(json.AppendKey(c.l.context, key), b...)
+	return c
+}
+
 // AnErr adds the field key with err as a string to the logger context.
 func (c Context) AnErr(key string, err error) Context {
 	if err != nil {

event.go

@@ -218,6 +218,15 @@ func (e *Event) Bytes(key string, val []byte) *Event {
 	return e
 }
 
+// RawJSON adds already encoded JSON to the log line under key.
+//
+// No sanity check is performed on b; it must not contain carriage returns and
+// be valid JSON.
+func (e *Event) RawJSON(key string, b []byte) *Event {
+	e.buf = append(json.AppendKey(e.buf, key), b...)
+	return e
+}
+
 // AnErr adds the field key with err as a string to the *Event context.
 // If err is nil, no field is added.
 func (e *Event) AnErr(key string, err error) *Event {

log_test.go

@@ -78,6 +78,7 @@ func TestWith(t *testing.T) {
 	out := &bytes.Buffer{}
 	ctx := New(out).With().
 		Str("foo", "bar").
+		RawJSON("json", []byte(`{"some":"json"}`)).
 		AnErr("some_err", nil).
 		Err(errors.New("some error")).
 		Bool("bool", true).
@@ -98,7 +99,7 @@ func TestWith(t *testing.T) {
 	caller := fmt.Sprintf("%s:%d", file, line+3)
 	log := ctx.Caller().Logger()
 	log.Log().Msg("")
-	if got, want := out.String(), `{"foo":"bar","error":"some error","bool":true,"int":1,"int8":2,"int16":3,"int32":4,"int64":5,"uint":6,"uint8":7,"uint16":8,"uint32":9,"uint64":10,"float32":11,"float64":12,"time":"0001-01-01T00:00:00Z","caller":"`+caller+`"}`+"\n"; got != want {
+	if got, want := out.String(), `{"foo":"bar","json":{"some":"json"},"error":"some error","bool":true,"int":1,"int8":2,"int16":3,"int32":4,"int64":5,"uint":6,"uint8":7,"uint16":8,"uint32":9,"uint64":10,"float32":11,"float64":12,"time":"0001-01-01T00:00:00Z","caller":"`+caller+`"}`+"\n"; got != want {
 		t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
 	}
 }
@@ -142,6 +143,7 @@ func TestFields(t *testing.T) {
 		Caller().
 		Str("string", "foo").
 		Bytes("bytes", []byte("bar")).
+		RawJSON("json", []byte(`{"some":"json"}`)).
 		AnErr("some_err", nil).
 		Err(errors.New("some error")).
 		Bool("bool", true).
@@ -161,7 +163,7 @@ func TestFields(t *testing.T) {
 		Time("time", time.Time{}).
 		TimeDiff("diff", now, now.Add(-10*time.Second)).
 		Msg("")
-	if got, want := out.String(), `{"caller":"`+caller+`","string":"foo","bytes":"bar","error":"some error","bool":true,"int":1,"int8":2,"int16":3,"int32":4,"int64":5,"uint":6,"uint8":7,"uint16":8,"uint32":9,"uint64":10,"float32":11,"float64":12,"dur":1000,"time":"0001-01-01T00:00:00Z","diff":10000}`+"\n"; got != want {
+	if got, want := out.String(), `{"caller":"`+caller+`","string":"foo","bytes":"bar","json":{"some":"json"},"error":"some error","bool":true,"int":1,"int8":2,"int16":3,"int32":4,"int64":5,"uint":6,"uint8":7,"uint16":8,"uint32":9,"uint64":10,"float32":11,"float64":12,"dur":1000,"time":"0001-01-01T00:00:00Z","diff":10000}`+"\n"; got != want {
 		t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
 	}
 }