background routine: add context cancel support

integration_tests/websocket_test.go

@@ -271,6 +271,7 @@ func (suite *WebSocketTestSuite) TestWebSocketMissingInvoice() {
 func (suite *WebSocketTestSuite) TearDownSuite() {
 	suite.invoiceUpdateSubCancelFn()
 	suite.websocketServer.Close()
+	clearTable(suite.service, "invoices")
 }
 
 func TestWebSocketSuite(t *testing.T) {

lib/service/invoicesubscription.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"database/sql"
 	"encoding/hex"
+	"fmt"
 	"strings"
 	"time"
 
@@ -122,6 +123,10 @@ func (svc *LndhubService) InvoiceUpdateSubscription(ctx context.Context) error {
 		return err
 	}
 	for {
+		select {
+		case <-ctx.Done():
+			return fmt.Errorf("Context was canceled")
+		default:
 			// receive the next invoice update
 			rawInvoice, err := invoiceSubscriptionStream.Recv()
 			if err != nil {
@@ -150,4 +155,5 @@ func (svc *LndhubService) InvoiceUpdateSubscription(ctx context.Context) error {
 				sentry.CaptureException(processingError)
 			}
 		}
+	}
 }