Add error return value from page.on handlers

browser/page_mapping.go

@@ -2,6 +2,7 @@ package browser
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"time"
 
@@ -457,7 +458,7 @@ func mapPageOn(vu moduleVU, p *common.Page) func(common.PageOnEventName, sobek.C
 		// Run the the event handler in the task queue to
 		// ensure that the handler is executed on the event loop.
 		tq := vu.taskQueueRegistry.get(ctx, p.TargetID())
-		eventHandler := func(event common.PageOnEvent) {
+		eventHandler := func(event common.PageOnEvent) error {
 			mapping := pageOnEvent.mapp(vu, event)
 
 			done := make(chan struct{})
@@ -480,8 +481,11 @@ func mapPageOn(vu moduleVU, p *common.Page) func(common.PageOnEventName, sobek.C
 				select {
 				case <-done:
 				case <-ctx.Done():
+					return errors.New("iteration ended before page.on handler completed executing")
 				}
 			}
+
+			return nil
 		}
 
 		return p.On(eventName, eventHandler) //nolint:wrapcheck

browser/sync_page_mapping.go

@@ -121,13 +121,15 @@ func syncMapPage(vu moduleVU, p *common.Page) mapping { //nolint:gocognit,cyclop
 				_, err := handler(sobek.Undefined(), vu.Runtime().ToValue(mapping))
 				return err
 			}
-			runInTaskQueue := func(a common.PageOnEvent) {
+			runInTaskQueue := func(a common.PageOnEvent) error {
 				tq.Queue(func() error {
 					if err := mapMsgAndHandleEvent(a.ConsoleMessage); err != nil {
 						return fmt.Errorf("executing page.on handler: %w", err)
 					}
 					return nil
 				})
+
+				return nil
 			}
 
 			return p.On(event, runInTaskQueue) //nolint:wrapcheck

common/page.go

@@ -207,6 +207,8 @@ type ConsoleMessage struct {
 	Type string
 }
 
+type PageOnHandler func(PageOnEvent) error
+
 // Page stores Page/tab related context.
 type Page struct {
 	BaseEventEmitter
@@ -245,7 +247,7 @@ type Page struct {
 	backgroundPage bool
 
 	eventCh         chan Event
-	eventHandlers   map[PageOnEventName][]func(PageOnEvent)
+	eventHandlers   map[PageOnEventName][]PageOnHandler
 	eventHandlersMu sync.RWMutex
 
 	mainFrameSession *FrameSession
@@ -284,7 +286,7 @@ func NewPage(
 		Keyboard:         NewKeyboard(ctx, s),
 		jsEnabled:        true,
 		eventCh:          make(chan Event),
-		eventHandlers:    make(map[PageOnEventName][]func(PageOnEvent)),
+		eventHandlers:    make(map[PageOnEventName][]PageOnHandler),
 		frameSessions:    make(map[cdp.FrameID]*FrameSession),
 		workers:          make(map[target.SessionID]*Worker),
 		vu:               k6ext.GetVU(ctx),
@@ -483,17 +485,21 @@ func (p *Page) urlTagName(url string, method string) (string, bool) {
 	p.eventHandlersMu.RLock()
 	defer p.eventHandlersMu.RUnlock()
 	for _, h := range p.eventHandlers[EventPageMetricCalled] {
-		func() {
+		err := func() error {
 			// Handlers can register other handlers, so we need to
 			// unlock the mutex before calling the next handler.
 			p.eventHandlersMu.RUnlock()
 			defer p.eventHandlersMu.RLock()
 
 			// Call and wait for the handler to complete.
-			h(PageOnEvent{
+			return h(PageOnEvent{
 				Metric: em,
 			})
 		}()
+		if err != nil {
+			p.logger.Debugf("urlTagName", "handler returned an error: %v", err)
+			return "", false
+		}
 	}
 
 	// If a match was found then the name field in em will have been updated.
@@ -521,9 +527,13 @@ func (p *Page) onConsoleAPICalled(event *cdpruntime.EventConsoleAPICalled) {
 	p.eventHandlersMu.RLock()
 	defer p.eventHandlersMu.RUnlock()
 	for _, h := range p.eventHandlers[EventPageConsoleAPICalled] {
-		h(PageOnEvent{
+		err := h(PageOnEvent{
 			ConsoleMessage: m,
 		})
+		if err != nil {
+			p.logger.Debugf("onConsoleAPICalled", "handler returned an error: %v", err)
+			return
+		}
 	}
 }
 
@@ -1194,12 +1204,12 @@ type PageOnEvent struct {
 // On subscribes to a page event for which the given handler will be executed
 // passing in the ConsoleMessage associated with the event.
 // The only accepted event value is 'console'.
-func (p *Page) On(event PageOnEventName, handler func(PageOnEvent)) error {
+func (p *Page) On(event PageOnEventName, handler PageOnHandler) error {
 	p.eventHandlersMu.Lock()
 	defer p.eventHandlersMu.Unlock()
 
 	if _, ok := p.eventHandlers[event]; !ok {
-		p.eventHandlers[event] = make([]func(PageOnEvent), 0, 1)
+		p.eventHandlers[event] = make([]PageOnHandler, 0, 1)
 	}
 	p.eventHandlers[event] = append(p.eventHandlers[event], handler)
 

tests/page_test.go

@@ -1251,14 +1251,16 @@ func TestPageOn(t *testing.T) {
 			)
 
 			// Console Messages should be multiplexed for every registered handler
-			eventHandlerOne := func(event common.PageOnEvent) {
+			eventHandlerOne := func(event common.PageOnEvent) error {
 				defer close(done1)
 				tc.assertFn(t, event.ConsoleMessage)
+				return nil
 			}
 
-			eventHandlerTwo := func(event common.PageOnEvent) {
+			eventHandlerTwo := func(event common.PageOnEvent) error {
 				defer close(done2)
 				tc.assertFn(t, event.ConsoleMessage)
+				return nil
 			}
 
 			// eventHandlerOne and eventHandlerTwo will be called from a

tests/remote_obj_test.go

@@ -81,9 +81,10 @@ func TestConsoleLogParse(t *testing.T) {
 
 			done := make(chan bool)
 
-			eventHandler := func(event common.PageOnEvent) {
+			eventHandler := func(event common.PageOnEvent) error {
 				defer close(done)
 				assert.Equal(t, tt.want, event.ConsoleMessage.Text)
+				return nil
 			}
 
 			// eventHandler will be called from a separate goroutine from within