doc to resolve go-rod#229

examples_test.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"math/rand"
+	"sync"
 	"time"
 
 	"github.com/go-rod/rod"
@@ -416,8 +417,7 @@ func Example_handle_events() {
 
 	// Listen for all events of console output.
 	go page.EachEvent(func(e *proto.RuntimeConsoleAPICalled) {
-		log := page.MustObjectsToJSON(e.Args).Join(" ")
-		fmt.Println(log)
+		fmt.Println(page.MustObjectsToJSON(e.Args))
 		close(done)
 	})()
 
@@ -458,7 +458,7 @@ func Example_handle_events() {
 	<-done
 
 	// Output:
-	// hello world
+	// [hello world]
 }
 
 // Shows how to intercept requests and modify
@@ -540,3 +540,49 @@ func ExamplePage_Event() {
 		fmt.Println(msg.Method, msg.Params)
 	}
 }
+
+// It's a common practice to concurrently use a pool of resources in Go, it's not special for rod.
+func ExamplePage_pool() {
+	browser := rod.New().MustConnect()
+	defer browser.MustClose()
+
+	// we create a pool that will hold at most 3 pages
+	pool := make(chan *rod.Page, 3)
+	for i := 0; i < cap(pool); i++ {
+		pool <- nil
+	}
+
+	// a function to get an item from the pool
+	getOnePage := func() (*rod.Page, func()) {
+		page := <-pool
+		if page == nil {
+			page = browser.MustPage("")
+		}
+		return page, func() { pool <- page }
+	}
+
+	yourJob := func() {
+		page, payback := getOnePage()
+		defer payback()
+
+		page.MustNavigate("http://example.com").MustWaitLoad()
+		fmt.Println(page.MustInfo().Title)
+	}
+
+	// run jobs concurrently
+	wg := sync.WaitGroup{}
+	for range "...." {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			yourJob()
+		}()
+	}
+	wg.Wait()
+
+	// Output:
+	// Example Domain
+	// Example Domain
+	// Example Domain
+	// Example Domain
+}

input.go

@@ -271,6 +271,9 @@ type Touch struct {
 
 // Start a touch action
 func (t *Touch) Start(points ...*proto.InputTouchPoint) error {
+	// TODO: https://crbug.com/613219
+	_, _ = t.page.Root().Eval(`new Promise(r => requestAnimationFrame(r)`)
+
 	return proto.InputDispatchTouchEvent{
 		Type:        proto.InputDispatchTouchEventTypeTouchStart,
 		TouchPoints: points,

page.go

@@ -462,12 +462,6 @@ func (p *Page) WaitIdle(timeout time.Duration) (err error) {
 // WaitLoad waits for the `window.onload` event, it returns immediately if the event is already fired.
 func (p *Page) WaitLoad() error {
 	_, err := p.Evaluate(jsHelper(js.WaitLoad))
-	if err != nil {
-		return err
-	}
-
-	// TODO: https://crbug.com/613219
-	_, err = p.Root().Eval(`new Promise(r => requestAnimationFrame(() => requestAnimationFrame(r)))`)
 	return err
 }
 

page_test.go

@@ -566,11 +566,11 @@ func (t T) NativeDrag(got.Skip) { // devtools doesn't support to use mouse event
 }
 
 func (t T) Touch() {
-	page := t.newPage("")
+	page := t.newPage("").MustEmulate(devices.IPad)
 
-	page.MustEmulate(devices.IPad).
-		MustNavigate(t.srcFile("fixtures/touch.html")).
-		MustWaitLoad()
+	wait := page.WaitNavigation(proto.PageLifecycleEventNameLoad)
+	page.MustNavigate(t.srcFile("fixtures/touch.html"))
+	wait()
 
 	touch := page.Touch
 
@@ -813,14 +813,22 @@ func (t T) PageWaitLoadErr() {
 func (t T) PageGoBackGoForward() {
 	p := t.newPage("").MustReload()
 
-	p.
-		MustNavigate(t.srcFile("fixtures/click.html")).MustWaitLoad().
-		MustNavigate(t.srcFile("fixtures/selector.html")).MustWaitLoad()
+	wait := p.WaitNavigation(proto.PageLifecycleEventNameDOMContentLoaded)
+	p.MustNavigate(t.srcFile("fixtures/click.html"))
+	wait()
+
+	wait = p.WaitNavigation(proto.PageLifecycleEventNameDOMContentLoaded)
+	p.MustNavigate(t.srcFile("fixtures/selector.html"))
+	wait()
 
-	p.MustNavigateBack().MustWaitLoad()
+	wait = p.WaitNavigation(proto.PageLifecycleEventNameDOMContentLoaded)
+	p.MustNavigateBack()
+	wait()
 	t.Regex("fixtures/click.html$", p.MustInfo().URL)
 
-	p.MustNavigateForward().MustWaitLoad()
+	wait = p.WaitNavigation(proto.PageLifecycleEventNameDOMContentLoaded)
+	p.MustNavigateForward()
+	wait()
 	t.Regex("fixtures/selector.html$", p.MustInfo().URL)
 }
 

setup_test.go

@@ -43,7 +43,7 @@ type T struct {
 }
 
 type TesterPool struct {
-	list   chan T
+	list   chan *T
 	logger *log.Logger
 }
 
@@ -58,7 +58,7 @@ func newTesterPool(t *testing.T) TesterPool {
 	lf := got.New(t).Open(true, "tmp", logName)
 
 	cp := TesterPool{
-		list:   make(chan T, parallel),
+		list:   make(chan *T, parallel),
 		logger: log.New(lf, "", log.Ltime),
 	}
 
@@ -70,21 +70,15 @@ func newTesterPool(t *testing.T) TesterPool {
 		}()
 	})
 
-	wg := &sync.WaitGroup{}
-	wg.Add(parallel)
 	for i := 0; i < parallel; i++ {
-		go func() {
-			cp.list <- cp.new()
-			wg.Done()
-		}()
+		cp.list <- nil
 	}
-	wg.Wait()
 
 	return cp
 }
 
 // new tester
-func (cp TesterPool) new() T {
+func (cp TesterPool) new() *T {
 	u := launcher.New().MustLaunch()
 
 	mc := newMockClient(cdp.New(u).Logger(cp.logger))
@@ -97,7 +91,7 @@ func (cp TesterPool) new() T {
 
 	page := getOnePage(browser)
 
-	return T{
+	return &T{
 		mc:      mc,
 		browser: browser,
 		page:    page,
@@ -111,6 +105,9 @@ func (cp TesterPool) get(t *testing.T) T {
 	}
 
 	tester := <-cp.list
+	if tester == nil {
+		tester = cp.new()
+	}
 	t.Cleanup(func() { cp.list <- tester })
 
 	if !testing.Short() {
@@ -132,11 +129,11 @@ func (cp TesterPool) get(t *testing.T) T {
 
 	heartBeat(tester)
 
-	return tester
+	return *tester
 }
 
 // when concurrently run tests, indicate the busy ones
-func heartBeat(t T) {
+func heartBeat(t *T) {
 	if !testing.Short() {
 		return
 	}