Add WriteOnly example

example_test.go

@@ -59,3 +59,45 @@ func ExampleDial() {
 
 	c.Close(websocket.StatusNormalClosure, "")
 }
+
+func ExampleWriteOnly() {
+	fn := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		c, err := websocket.Accept(w, r, websocket.AcceptOptions{})
+		if err != nil {
+			log.Println(err)
+			return
+		}
+		defer c.Close(websocket.StatusInternalError, "the sky is falling")
+
+		ctx, cancel := context.WithTimeout(r.Context(), time.Minute*10)
+		defer cancel()
+
+		go func() {
+			defer cancel()
+			_, _, err := c.Reader(ctx)
+			if err == nil {
+				c.Close(websocket.StatusPolicyViolation, "server doesn't accept data messages")
+			}
+		}()
+
+		t := time.NewTicker(time.Second * 30)
+		defer t.Stop()
+
+		for {
+			select {
+			case <-ctx.Done():
+				c.Close(websocket.StatusNormalClosure, "")
+				return
+			case <-t.C:
+				err = wsjson.Write(ctx, c, "hi")
+				if err != nil {
+					log.Println(err)
+					return
+				}
+			}
+		}
+	})
+
+	err := http.ListenAndServe("localhost:8080", fn)
+	log.Fatal(err)
+}

websocket.go

@@ -21,6 +21,9 @@ import (
 // All methods may be called concurrently except for Reader, Read
 // and SetReadLimit.
 //
+// You must always read from the connection. Otherwise control
+// frames will not be handled. See the docs on Reader.
+//
 // Please be sure to call Close on the connection when you
 // are finished with it to release the associated resources.
 type Conn struct {
@@ -299,7 +302,7 @@ func (c *Conn) handleControl(ctx context.Context, h header) error {
 // You must read from the connection for close frames to be read.
 // If you do not expect any data messages from the peer, just call
 // Reader in a separate goroutine and close the connection with StatusPolicyViolation
-// when it returns. Example at // TODO
+// when it returns. See the WriteOnly example.
 //
 // Only one Reader may be open at a time.
 //