Add WebSocket transport and working CLI example + unit tests

conn_ws.go

@@ -0,0 +1,44 @@
+package ownwire_sdk
+
+import (
+	"context"
+	"fmt"
+
+	"nhooyr.io/websocket"
+)
+
+type WsConn struct {
+	conn *websocket.Conn
+}
+
+func DialWs(ctx context.Context, url string) (*WsConn, error) {
+	conn, _, err := websocket.Dial(ctx, url, nil)
+	if err != nil {
+		return nil, err
+	}
+	return &WsConn{conn: conn}, nil
+}
+
+func (c *WsConn) WriteText(ctx context.Context, s string) error {
+	return c.conn.Write(ctx, websocket.MessageText, []byte(s))
+}
+
+func (c *WsConn) ReadText(ctx context.Context) (string, error) {
+	msg_type, data, err := c.conn.Read(ctx)
+	if err != nil {
+		return "", err
+	}
+
+	if msg_type != websocket.MessageText {
+		// We only expect text frames. If something else arrives, surface it.
+		return "", fmt.Errorf("unexpected websocket message type: %v", msg_type)
+	}
+
+	return string(data), nil
+}
+
+func (c *WsConn) Close() error {
+	// Normal closure.
+	return c.conn.Close(websocket.StatusNormalClosure, "normal")
+}
+