feat: add ReadJSON and WriteJSON to ws connection (#5)

* feat: add ReadJSON and WriteJSON to ws connection

* fix: add CloudWeGo license header

Co-authored-by: Nicholas <[email protected]>

json.go

@@ -0,0 +1,48 @@
+// Copyright 2017 The Gorilla WebSocket Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+//
+// This file may have been modified by CloudWeGo authors. All CloudWeGo
+// Modifications are Copyright 2022 CloudWeGo Authors.
+
+package websocket
+
+import (
+ "encoding/json"
+ "io"
+)
+
+// WriteJSON writes the JSON encoding of v as a message.
+//
+// See the documentation for encoding/json Marshal for details about the
+// conversion of Go values to JSON.
+func (c *Conn) WriteJSON(v interface{}) error {
+ w, err := c.NextWriter(TextMessage)
+ if err != nil {
+ return err
+ }
+ err1 := json.NewEncoder(w).Encode(v)
+ err2 := w.Close()
+ if err1 != nil {
+ return err1
+ }
+ return err2
+}
+
+// ReadJSON reads the next JSON-encoded message from the connection and stores
+// it in the value pointed to by v.
+//
+// See the documentation for the encoding/json Unmarshal function for details
+// about the conversion of JSON to a Go value.
+func (c *Conn) ReadJSON(v interface{}) error {
+ _, r, err := c.NextReader()
+ if err != nil {
+ return err
+ }
+ err = json.NewDecoder(r).Decode(v)
+ if err == io.EOF {
+ // One value is expected in the message.
+ err = io.ErrUnexpectedEOF
+ }
+ return err
+}

json_test.go

@@ -0,0 +1,94 @@
+// Copyright 2017 The Gorilla WebSocket Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+//
+// This file may have been modified by CloudWeGo authors. All CloudWeGo
+// Modifications are Copyright 2022 CloudWeGo Authors.
+
+package websocket
+
+import (
+ "bytes"
+ "encoding/json"
+ "io"
+ "reflect"
+ "testing"
+)
+
+func TestJSON(t *testing.T) {
+ var buf bytes.Buffer
+ wc := newTestConn(nil, &buf, true)
+ rc := newTestConn(&buf, nil, false)
+
+ var actual, expect struct {
+ A int
+ B string
+ }
+ expect.A = 1
+ expect.B = "hello"
+
+ if err := wc.WriteJSON(&expect); err != nil {
+ t.Fatal("write", err)
+ }
+
+ if err := rc.ReadJSON(&actual); err != nil {
+ t.Fatal("read", err)
+ }
+
+ if !reflect.DeepEqual(&actual, &expect) {
+ t.Fatal("equal", actual, expect)
+ }
+}
+
+func TestPartialJSONRead(t *testing.T) {
+ var buf0, buf1 bytes.Buffer
+ wc := newTestConn(nil, &buf0, true)
+ rc := newTestConn(&buf0, &buf1, false)
+
+ var v struct {
+ A int
+ B string
+ }
+ v.A = 1
+ v.B = "hello"
+
+ messageCount := 0
+
+ // Partial JSON values.
+
+ data, err := json.Marshal(v)
+ if err != nil {
+ t.Fatal(err)
+ }
+ for i := len(data) - 1; i >= 0; i-- {
+ if err := wc.WriteMessage(TextMessage, data[:i]); err != nil {
+ t.Fatal(err)
+ }
+ messageCount++
+ }
+
+ // Whitespace.
+
+ if err := wc.WriteMessage(TextMessage, []byte(" ")); err != nil {
+ t.Fatal(err)
+ }
+ messageCount++
+
+ // Close.
+
+ if err := wc.WriteMessage(CloseMessage, FormatCloseMessage(CloseNormalClosure, "")); err != nil {
+ t.Fatal(err)
+ }
+
+ for i := 0; i < messageCount; i++ {
+ err := rc.ReadJSON(&v)
+ if err != io.ErrUnexpectedEOF {
+ t.Error("read", i, err)
+ }
+ }
+
+ err = rc.ReadJSON(&v)
+ if _, ok := err.(*CloseError); !ok {
+ t.Error("final", err)
+ }
+}