Limit browser implementation to hold a single browserContext

common/browser.go

@@ -50,8 +50,7 @@ type Browser struct {
 	// A *Connection is saved to this field, see: connect().
 	conn connection
 
-	contextsMu     sync.RWMutex
-	contexts       map[cdp.BrowserContextID]*BrowserContext
+	context        *BrowserContext
 	defaultContext *BrowserContext
 
 	// Cancel function to stop event listening
@@ -103,7 +102,6 @@ func newBrowser(
 		state:               int64(BrowserStateOpen),
 		browserProc:         browserProc,
 		browserOpts:         browserOpts,
-		contexts:            make(map[cdp.BrowserContextID]*BrowserContext),
 		pages:               make(map[target.ID]*Page),
 		sessionIDtoTargetID: make(map[target.SessionID]target.ID),
 		vu:                  k6ext.GetVU(ctx),
@@ -137,23 +135,19 @@ func (b *Browser) disposeContext(id cdp.BrowserContextID) error {
 		return fmt.Errorf("disposing browser context ID %s: %w", id, err)
 	}
 
-	b.contextsMu.Lock()
-	defer b.contextsMu.Unlock()
-	delete(b.contexts, id)
+	b.context = nil
 
 	return nil
 }
 
-// getDefaultBrowserContextOrByID returns the BrowserContext for the given page ID.
+// getDefaultBrowserContextOrMatchedID returns the BrowserContext for the given browser context ID.
 // If the browser context is not found, the default BrowserContext is returned.
-func (b *Browser) getDefaultBrowserContextOrByID(id cdp.BrowserContextID) *BrowserContext {
-	b.contextsMu.RLock()
-	defer b.contextsMu.RUnlock()
-	browserCtx := b.defaultContext
-	if bctx, ok := b.contexts[id]; ok {
-		browserCtx = bctx
-	}
-	return browserCtx
+func (b *Browser) getDefaultBrowserContextOrMatchedID(id cdp.BrowserContextID) *BrowserContext {
+	if b.context == nil || b.context.id != id {
+		return b.defaultContext
+	}
+
+	return b.context
 }
 
 func (b *Browser) getPages() []*Page {
@@ -227,7 +221,7 @@ func (b *Browser) onAttachedToTarget(ev *target.EventAttachedToTarget) {
 
 	var (
 		targetPage = ev.TargetInfo
-		browserCtx = b.getDefaultBrowserContextOrByID(targetPage.BrowserContextID)
+		browserCtx = b.getDefaultBrowserContextOrMatchedID(targetPage.BrowserContextID)
 	)
 
 	if !b.isAttachedPageValid(ev, browserCtx) {
@@ -377,11 +371,8 @@ func (b *Browser) onDetachedFromTarget(ev *target.EventDetachedFromTarget) {
 }
 
 func (b *Browser) newPageInContext(id cdp.BrowserContextID) (*Page, error) {
-	b.contextsMu.RLock()
-	browserCtx, ok := b.contexts[id]
-	b.contextsMu.RUnlock()
-	if !ok {
-		return nil, fmt.Errorf("missing browser context: %s", id)
+	if b.context == nil || b.context.id != id {
+		return nil, fmt.Errorf("missing browser context %s, current context is %s", id, b.context.id)
 	}
 
 	ctx, cancel := context.WithTimeout(b.ctx, b.browserOpts.Timeout)
@@ -393,7 +384,7 @@ func (b *Browser) newPageInContext(id cdp.BrowserContextID) (*Page, error) {
 
 	waitForPage, removeEventHandler := createWaitForEventHandler(
 		ctx,
-		browserCtx, // browser context will emit the following event:
+		b.context, // browser context will emit the following event:
 		[]string{EventBrowserContextPage},
 		func(e any) bool {
 			tid := <-targetID
@@ -494,15 +485,11 @@ func (b *Browser) Close() {
 
 // Contexts returns list of browser contexts.
 func (b *Browser) Contexts() []api.BrowserContext {
-	b.contextsMu.RLock()
-	defer b.contextsMu.RUnlock()
-
-	contexts := make([]api.BrowserContext, 0, len(b.contexts))
-	for _, b := range b.contexts {
-		contexts = append(contexts, b)
+	if b.context == nil {
+		return []api.BrowserContext{}
 	}
 
-	return contexts
+	return []api.BrowserContext{b.context}
 }
 
 // IsConnected returns whether the WebSocket connection to the browser process
@@ -513,6 +500,10 @@ func (b *Browser) IsConnected() bool {
 
 // NewContext creates a new incognito-like browser context.
 func (b *Browser) NewContext(opts goja.Value) (api.BrowserContext, error) {
+	if b.context != nil {
+		return nil, errors.New("existing browser context must be closed before creating a new one")
+	}
+
 	action := target.CreateBrowserContext().WithDisposeOnDetach(true)
 	browserContextID, err := action.Do(cdp.WithExecutor(b.ctx, b.conn))
 	b.logger.Debugf("Browser:NewContext", "bctxid:%v", browserContextID)
@@ -525,13 +516,11 @@ func (b *Browser) NewContext(opts goja.Value) (api.BrowserContext, error) {
 		k6ext.Panic(b.ctx, "parsing newContext options: %w", err)
 	}
 
-	b.contextsMu.Lock()
-	defer b.contextsMu.Unlock()
 	browserCtx, err := NewBrowserContext(b.ctx, b, browserContextID, browserCtxOpts, b.logger)
 	if err != nil {
 		return nil, fmt.Errorf("new context: %w", err)
 	}
-	b.contexts[browserContextID] = browserCtx
+	b.context = browserCtx
 
 	return browserCtx, nil
 }

common/browser_test.go

@@ -31,11 +31,11 @@ func TestBrowserNewPageInContext(t *testing.T) {
 		var err error
 		vu := k6test.NewVU(t)
 		ctx = k6ext.WithVU(ctx, vu)
-		b.contexts[id], err = NewBrowserContext(ctx, b, id, nil, nil)
+		b.context, err = NewBrowserContext(ctx, b, id, nil, nil)
 		require.NoError(t, err)
 		return &testCase{
 			b:  b,
-			bc: b.contexts[id],
+			bc: b.context,
 		}
 	}
 

tests/browser_test.go

@@ -22,22 +22,48 @@ import (
 
 func TestBrowserNewPage(t *testing.T) {
 	b := newTestBrowser(t)
-	p := b.NewPage(nil)
+	p1 := b.NewPage(nil)
 	l := len(b.Contexts())
 	assert.Equal(t, 1, l, "expected there to be 1 browser context, but found %d", l)
 
-	p2 := b.NewPage(nil)
-	l = len(b.Contexts())
-	assert.Equal(t, 2, l, "expected there to be 2 browser context, but found %d", l)
+	_, err := b.Browser.NewPage(nil)
+	assert.EqualError(t, err, "new page: existing browser context must be closed before creating a new one")
 
-	err := p.Close(nil)
+	err = p1.Close(nil)
 	require.NoError(t, err)
 	l = len(b.Contexts())
-	assert.Equal(t, 2, l, "expected there to be 2 browser contexts after first page close, but found %d", l)
-	err = p2.Close(nil)
-	require.NoError(t, err)
+	assert.Equal(t, 1, l, "expected there to be 1 browser context, but found %d", l)
+
+	_, err = b.Browser.NewPage(nil)
+	assert.EqualError(t, err, "new page: existing browser context must be closed before creating a new one")
+
+	b.Contexts()[0].Close()
+	l = len(b.Contexts())
+	assert.Equal(t, 0, l, "expected there to be 0 browser context, but found %d", l)
+
+	_ = b.NewPage(nil)
 	l = len(b.Contexts())
-	assert.Equal(t, 2, l, "expected there to be 2 browser contexts after second page close, but found %d", l)
+	assert.Equal(t, 1, l, "expected there to be 1 browser context, but found %d", l)
+}
+
+func TestBrowserNewContext(t *testing.T) {
+	b := newTestBrowser(t)
+	bc1, err := b.NewContext(nil)
+	assert.NoError(t, err)
+	l := len(b.Contexts())
+	assert.Equal(t, 1, l, "expected there to be 1 browser context, but found %d", l)
+
+	_, err = b.NewContext(nil)
+	assert.EqualError(t, err, "existing browser context must be closed before creating a new one")
+
+	bc1.Close()
+	l = len(b.Contexts())
+	assert.Equal(t, 0, l, "expected there to be 0 browser context, but found %d", l)
+
+	_, err = b.NewContext(nil)
+	assert.NoError(t, err)
+	l = len(b.Contexts())
+	assert.Equal(t, 1, l, "expected there to be 1 browser context, but found %d", l)
 }
 
 func TestTmpDirCleanup(t *testing.T) {

tests/keyboard_test.go

@@ -12,9 +12,8 @@ import (
 )
 
 func TestKeyboardPress(t *testing.T) {
-	tb := newTestBrowser(t)
-
 	t.Run("all_keys", func(t *testing.T) {
+		tb := newTestBrowser(t)
 		p := tb.NewPage(nil)
 		kb := p.GetKeyboard()
 		layout := keyboardlayout.GetKeyboardLayout("us")
@@ -27,6 +26,7 @@ func TestKeyboardPress(t *testing.T) {
 	})
 
 	t.Run("backspace", func(t *testing.T) {
+		tb := newTestBrowser(t)
 		p := tb.NewPage(nil)
 		kb := p.GetKeyboard()
 
@@ -43,6 +43,7 @@ func TestKeyboardPress(t *testing.T) {
 	})
 
 	t.Run("combo", func(t *testing.T) {
+		tb := newTestBrowser(t)
 		p := tb.NewPage(nil)
 		kb := p.GetKeyboard()
 
@@ -68,6 +69,7 @@ func TestKeyboardPress(t *testing.T) {
 
 	t.Run("meta", func(t *testing.T) {
 		t.Skip("FIXME") // See https://github.com/grafana/xk6-browser/issues/424
+		tb := newTestBrowser(t)
 		p := tb.NewPage(nil)
 		kb := p.GetKeyboard()
 
@@ -92,6 +94,7 @@ func TestKeyboardPress(t *testing.T) {
 	})
 
 	t.Run("type does not split on +", func(t *testing.T) {
+		tb := newTestBrowser(t)
 		p := tb.NewPage(nil)
 		kb := p.GetKeyboard()
 
@@ -105,6 +108,7 @@ func TestKeyboardPress(t *testing.T) {
 	})
 
 	t.Run("capitalization", func(t *testing.T) {
+		tb := newTestBrowser(t)
 		p := tb.NewPage(nil)
 		kb := p.GetKeyboard()
 
@@ -130,6 +134,7 @@ func TestKeyboardPress(t *testing.T) {
 	})
 
 	t.Run("type not affected by shift", func(t *testing.T) {
+		tb := newTestBrowser(t)
 		p := tb.NewPage(nil)
 		kb := p.GetKeyboard()
 
@@ -146,6 +151,7 @@ func TestKeyboardPress(t *testing.T) {
 	})
 
 	t.Run("newline", func(t *testing.T) {
+		tb := newTestBrowser(t)
 		p := tb.NewPage(nil)
 		kb := p.GetKeyboard()
 
@@ -163,6 +169,7 @@ func TestKeyboardPress(t *testing.T) {
 
 	// Replicates the test from https://playwright.dev/docs/api/class-keyboard
 	t.Run("selection", func(t *testing.T) {
+		tb := newTestBrowser(t)
 		p := tb.NewPage(nil)
 		kb := p.GetKeyboard()
 

tests/network_manager_test.go

@@ -74,11 +74,10 @@ func TestBasicAuth(t *testing.T) {
 		validPassword = "validpass"
 	)
 
-	browser := newTestBrowser(t, withHTTPServer())
-
 	auth := func(tb testing.TB, user, pass string) api.Response {
 		tb.Helper()
 
+		browser := newTestBrowser(t, withHTTPServer())
 		bc, err := browser.NewContext(
 			browser.toGojaValue(struct {
 				HttpCredentials *common.Credentials `js:"httpCredentials"` //nolint:revive