Make blob the default binaryType

Fixes #67

websockets/websockets.go

@@ -137,6 +137,7 @@ func (r *WebSocketsAPI) websocket(c sobek.ConstructorCall) *sobek.Object {
 		obj:             rt.NewObject(),
 		tagsAndMeta:     params.tagsAndMeta,
 		sendPings:       ping{timestamps: make(map[string]time.Time)},
+		binaryType:      blobBinaryType,
 	}
 
 	// Maybe have this after the goroutine below ?!?
@@ -421,10 +422,6 @@ func (w *webSocket) loop() {
 	}
 }
 
-const binarytypeError = `websocket's binaryType hasn't been set to either "blob" or "arraybuffer", ` +
-	`but a binary message has been received. ` +
-	`"blob" is still not the default so the websocket is erroring out`
-
 func (w *webSocket) queueMessage(msg *message) {
 	w.tq.Queue(func() error {
 		if w.readyState != OPEN {
@@ -446,12 +443,7 @@ func (w *webSocket) queueMessage(msg *message) {
 
 		if msg.mtype == websocket.BinaryMessage {
 			var data any
-			// Lets error out for a k6 release, at least, when there's no binaryType set.
-			// In the future, we'll use "blob" as default, as per spec:
-			// https://developer.mozilla.org/en-US/docs/Web/API/WebSocket/binaryType
 			switch w.binaryType {
-			case "":
-				return errors.New(binarytypeError)
 			case blobBinaryType:
 				var err error
 				data, err = rt.New(w.blobConstructor, rt.ToValue([]interface{}{msg.data}))
@@ -461,7 +453,7 @@ func (w *webSocket) queueMessage(msg *message) {
 			case arraybufferBinaryType:
 				data = rt.NewArrayBuffer(msg.data)
 			default:
-				return fmt.Errorf(`unknown binaryType %s, the supported ones are "blob" and "arraybuffer"`, w.binaryType)
+				return fmt.Errorf(`unknown binaryType %q, the supported ones are "blob" and "arraybuffer"`, w.binaryType)
 			}
 			must(rt, ev.DefineDataProperty("data", rt.ToValue(data), sobek.FLAG_FALSE, sobek.FLAG_FALSE, sobek.FLAG_TRUE))
 		} else {

websockets/websockets_test.go

@@ -319,8 +319,8 @@ func TestBinaryState(t *testing.T) {
 			}
 		})
 
-		if (ws.binaryType != "") {
-			throw new Error("Wrong binaryType value, expected empty got "+ ws.binaryType)
+		if (ws.binaryType != "blob") {
+			throw new Error("Wrong binaryType value, expected to be blob got "+ ws.binaryType)
 		}
 
 		var thrown = false;
@@ -330,11 +330,10 @@ func TestBinaryState(t *testing.T) {
 			thrown = true
 		}
 		if (!thrown) {
-			throw new Error("Expects ws.binaryType to not be writable")
+			throw new Error("Expects ws.binaryType to be writable only with valid values")
 		}
 	`))
-	require.Error(t, err)
-	require.ErrorContains(t, err, binarytypeError)
+	require.NoError(t, err)
 	logs := hook.Drain()
 	require.Len(t, logs, 0)
 }
@@ -349,21 +348,21 @@ func TestBinaryType_Default(t *testing.T) {
 		ws.addEventListener("open", () => {
 			const sent = new Uint8Array([164,41]).buffer
 			ws.send(sent)
-			ws.onmessage = (e) => {
+			ws.onmessage = async (e) => {
 				if (!(e.data instanceof Blob)) {
 					throw new Error("Wrong event.data type; expected: Blob, got: "+ typeof e.data)
 				}
+				const received = await e.data.arrayBuffer();
 
-				if (sent.byteLength !== e.data.arrayBuffer().byteLength) {
-					throw new Error("The data received isn't equal to the data sent")
+				if (sent.byteLength !== received.byteLength) {
+					throw new Error("The data received " + received.byteLength +" isn't equal to the data sent "+ sent.byteLength)
 				}
 
 				ws.close()
 			}
 		})
 	`))
-	require.Error(t, err)
-	require.ErrorContains(t, err, binarytypeError)
+	require.NoError(t, err)
 	logs := hook.Drain()
 	require.Len(t, logs, 0)
 }