should use sleeper generator for operations

browser.go

@@ -34,7 +34,7 @@ type Browser struct {
 	ctx           context.Context
 	ctxCancel     func()
 	timeoutCancel func()
-	sleeper       utils.Sleeper
+	sleeper       func() utils.Sleeper
 
 	// BrowserContextID is the id for incognito window
 	BrowserContextID proto.BrowserBrowserContextID
@@ -61,7 +61,7 @@ type Browser struct {
 // New creates a controller
 func New() *Browser {
 	b := &Browser{
-		sleeper:     Sleeper,
+		sleeper:     DefaultSleeper,
 		lock:        &sync.Mutex{},
 		slowmotion:  defaults.Slow,
 		quiet:       defaults.Quiet,

context.go

@@ -34,9 +34,9 @@ func (b *Browser) CancelTimeout() *Browser {
 }
 
 // Sleeper for chained sub-operations
-func (b *Browser) Sleeper(sleeper utils.Sleeper) *Browser {
+func (b *Browser) Sleeper(sleeper func() utils.Sleeper) *Browser {
 	newObj := *b
-	newObj.sleeper = sleeper
+	newObj.sleeper = ensureSleeper(sleeper)
 	return &newObj
 }
 
@@ -67,9 +67,9 @@ func (p *Page) CancelTimeout() *Page {
 }
 
 // Sleeper for chained sub-operations
-func (p *Page) Sleeper(sleeper utils.Sleeper) *Page {
+func (p *Page) Sleeper(sleeper func() utils.Sleeper) *Page {
 	newObj := *p
-	newObj.sleeper = sleeper
+	newObj.sleeper = ensureSleeper(sleeper)
 	return &newObj
 }
 
@@ -100,8 +100,8 @@ func (el *Element) CancelTimeout() *Element {
 }
 
 // Sleeper for chained sub-operations
-func (el *Element) Sleeper(sleeper utils.Sleeper) *Element {
+func (el *Element) Sleeper(sleeper func() utils.Sleeper) *Element {
 	newObj := *el
-	newObj.sleeper = sleeper
+	newObj.sleeper = ensureSleeper(sleeper)
 	return &newObj
 }

element.go

@@ -21,7 +21,7 @@ type Element struct {
 	ctx           context.Context
 	ctxCancel     func()
 	timeoutCancel func()
-	sleeper       utils.Sleeper
+	sleeper       func() utils.Sleeper
 
 	page *Page
 
@@ -405,7 +405,7 @@ func (el *Element) WaitStable(interval time.Duration) error {
 
 // Wait doc is similar to the method MustWait
 func (el *Element) Wait(js string, params ...interface{}) error {
-	return utils.Retry(el.ctx, el.sleeper, func() (bool, error) {
+	return utils.Retry(el.ctx, el.sleeper(), func() (bool, error) {
 		res, err := el.Eval(js, params...)
 		if err != nil {
 			return true, err

element_test.go

@@ -91,7 +91,7 @@ func (s *S) TestHover() {
 func (s *S) TestElementContext() {
 	p := s.page.MustNavigate(srcFile("fixtures/click.html"))
 	el := p.MustElement("button").Timeout(time.Minute).CancelTimeout()
-	s.Error(el.Click(proto.InputMouseButtonLeft))
+	s.Error(el.Sleeper(rod.DefaultSleeper).Click(proto.InputMouseButtonLeft))
 }
 
 func (s *S) TestIframes() {

examples_test.go

@@ -11,6 +11,7 @@ import (
 	"github.com/go-rod/rod/lib/input"
 	"github.com/go-rod/rod/lib/launcher"
 	"github.com/go-rod/rod/lib/proto"
+	"github.com/go-rod/rod/lib/utils"
 )
 
 // Example_basic is a simple test that opens https://github.com/, searches for
@@ -195,9 +196,11 @@ func Example_customize_retry_strategy() {
 	page := browser.MustPage("https://github.com")
 
 	// sleep for 0.5 seconds before every retry
-	sleeper := func(context.Context) error {
-		time.Sleep(time.Second / 2)
-		return nil
+	sleeper := func() utils.Sleeper {
+		return func(context.Context) error {
+			time.Sleep(time.Second / 2)
+			return nil
+		}
 	}
 	el, _ := page.Sleeper(sleeper).Element("input")
 

lib/utils/utils.go

@@ -168,7 +168,7 @@ func Sleep(seconds float64) {
 }
 
 // Sleeper sleeps for sometime, returns the reason to wake, if ctx is done release resource
-type Sleeper func(ctx context.Context) error
+type Sleeper func(context.Context) error
 
 // ErrMaxSleepCount ...
 var ErrMaxSleepCount = errors.New("max sleep count")

page.go

@@ -30,7 +30,7 @@ type Page struct {
 	ctx           context.Context
 	ctxCancel     func()
 	timeoutCancel func()
-	sleeper       utils.Sleeper
+	sleeper       func() utils.Sleeper
 
 	browser *Browser
 
@@ -542,9 +542,9 @@ func (p *Page) EvalWithOptions(opts *EvalOptions) (*proto.RuntimeRemoteObject, e
 
 // Wait js function until it returns true
 func (p *Page) Wait(thisID proto.RuntimeRemoteObjectID, js string, params Array) error {
-	sleeper := p.sleeper
+	sleeper := p.sleeper()
 	if sleeper == nil {
-		sleeper = func(_ context.Context) error {
+		sleeper = func(context.Context) error {
 			return newErr(ErrWaitJSTimeout, js, js)
 		}
 	}

query.go

@@ -141,9 +141,9 @@ func (p *Page) ElementByJS(opts *EvalOptions) (*Element, error) {
 	var res *proto.RuntimeRemoteObject
 	var err error
 
-	sleeper := p.sleeper
+	sleeper := p.sleeper()
 	if sleeper == nil {
-		sleeper = func(_ context.Context) error {
+		sleeper = func(context.Context) error {
 			return newErr(ErrElementNotFound, opts, opts.JS)
 		}
 	}
@@ -230,9 +230,9 @@ func (p *Page) ElementsByJS(opts *EvalOptions) (Elements, error) {
 // The query can be plain text or css selector or xpath.
 // It will search nested iframes and shadow doms too.
 func (p *Page) Search(from, to int, queries ...string) (Elements, error) {
-	sleeper := p.sleeper
+	sleeper := p.sleeper()
 	if sleeper == nil {
-		sleeper = func(_ context.Context) error {
+		sleeper = func(context.Context) error {
 			return newErr(ErrElementNotFound, queries, fmt.Sprintf("%v", queries))
 		}
 	}

setup_test.go

@@ -63,7 +63,7 @@ func Test(t *testing.T) {
 	s.browser = rod.New().ControlURL("").Client(s.client).MustConnect().
 		DefaultViewport(&proto.EmulationSetDeviceMetricsOverride{
 			Width: 800, Height: 600, DeviceScaleFactor: 1,
-		})
+		}).Sleeper(rod.DefaultSleeper)
 
 	defer s.browser.MustClose()
 

utils.go

@@ -22,9 +22,18 @@ import (
 // CDPCall type for cdp.Client.CDPCall
 type CDPCall func(ctx context.Context, sessionID, method string, params interface{}) ([]byte, error)
 
-// Sleeper is the default sleeper for retry, it uses backoff to grow the interval.
+// DefaultSleeper generates the default sleeper for retry, it uses backoff to grow the interval.
 // The growth looks like: A(0) = 100ms, A(n) = A(n-1) * random[1.9, 2.1), A(n) < 1s
-var Sleeper = utils.BackoffSleeper(100*time.Millisecond, time.Second, nil)
+var DefaultSleeper = func() utils.Sleeper {
+	return utils.BackoffSleeper(100*time.Millisecond, time.Second, nil)
+}
+
+func ensureSleeper(gen func() utils.Sleeper) func() utils.Sleeper {
+	if gen == nil {
+		return func() utils.Sleeper { return nil }
+	}
+	return gen
+}
 
 // Array of any type
 type Array []interface{}