add a configurable timeout for responses received from the server

if no response after the timeout, the request responds with an error

new option is `WithResponseTimeout(x time.Duration)`

api/requests/client.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
+	"time"
 
 	"github.com/gorilla/websocket"
 	uuid "github.com/nu7hatch/gouuid"
@@ -23,6 +24,9 @@ type Client struct {
 	// The backing websocket connection to the OBS websocket server.
 	Conn *websocket.Conn
 
+	// The time we're willing to wait to receive a response from the server.
+	ResponseTimeout time.Duration
+
 	// Raw JSON message responses from the websocker server.
 	IncomingResponses chan json.RawMessage
 
@@ -85,7 +89,12 @@ func (c *Client) SendRequest(params Params, response Response) error {
 		return err
 	}
 
-	msg := <-c.IncomingResponses
+	var msg json.RawMessage
+	select {
+	case msg = <-c.IncomingResponses:
+	case <-time.After(c.ResponseTimeout * time.Millisecond):
+		return fmt.Errorf("Timed out receiving response from server for request %q", params.GetRequestType())
+	}
 
 	// OBS websocket seems to return already pretty-printed JSON in its
 	// responses, so we compact the response to print it on just one line.

client.go

@@ -9,6 +9,7 @@ import (
 	"net/http"
 	"net/url"
 	"os"
+	"time"
 
 	"github.com/andreykaipov/goobs/api/events"
 	"github.com/andreykaipov/goobs/api/requests"
@@ -77,6 +78,15 @@ func WithRequestHeader(x http.Header) Option {
 	}
 }
 
+// WithResponseTimeout sets the time we're willing to wait to receive a response
+// from the server for any request, before responding with an error. It's in
+// milliseconds. The default timeout is 10 seconds.
+func WithResponseTimeout(x time.Duration) Option {
+	return func(o *Client) {
+		o.ResponseTimeout = time.Duration(x)
+	}
+}
+
 type discard struct{}
 
 func (o *discard) Printf(format string, v ...interface{}) {}
@@ -93,8 +103,10 @@ It also opens up a connection, so be sure to check the error.
 */
 func New(host string, opts ...Option) (*Client, error) {
 	c := &Client{
-		Client: &requests.Client{},
-		host:   host,
+		Client: &requests.Client{
+			ResponseTimeout: 10000,
+		},
+		host: host,
 	}
 
 	for _, opt := range opts {