Hold JavaScript dialogs open for the agent or the person to answer

CHANGELOG.md

@@ -14,10 +14,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - The agent can wait for its browser page to change instead of reading it again in a loop. `browser_info` takes `wait_for` (text that should appear) and `wait_gone` (text that should disappear), matched anywhere on the page, and answers as soon as the page shows it, or after 20 seconds with the page as it stands and a line saying the wait timed out.
 - The agent hears when the page in its session's browser breaks. Each page it reads, clicks or presses a key on answers with the console errors since its last look, once each: `console.error` calls, uncaught exceptions and resources that failed to load, cut to one short line, the first five and how many more. Warnings and other messages stay out.
 - An agent can close a project, with `close_project` or `lich close-project`: the tab leaves the window and its sessions stop, kept for a reopen as when you close the tab. The project the agent runs in and the home project are refused.
+- The agent and you answer the page's JavaScript dialogs in a session's browser. An alert, a confirm, a prompt or a "Leave this page?" the page opens shows as a card over the top of the page in the session's browser tab, naming the site that opened it, with its buttons and, for a prompt, a field. You answer it there, or the agent does with `browser_dialog`, and its cursor presses the card's button. The agent's click that opened a dialog answers at once with the dialog in it, and the agent hears of one you answered. Before, a button that showed an alert froze the page: the agent's click and every read after it waited thirty seconds and failed.
 
 ### Changed
 
 - The window holds less memory with many sessions open. A terminal off screen lets go of the pixels it drew, a few megabytes each, and redraws them in one frame when it comes back.
+- The browser tools answer an agent in the session's prompt language: the legend of the element list, the note that more elements wait below, the filled and checked marks, a download still running, a wait that timed out, the count of further console errors, and what an open dialog asks of it. The line tags (`url:`, `text:`, `downloaded:`, `console error:`, `dialog open:` and the rest) stay as they are in every language.
 
 ### Fixed
 

api/browser.go

@@ -20,6 +20,9 @@ var (
 	BrowserScroll     = define[BrowserScrollOptions, None]("browser.Scroll")
 	BrowserList       = define[SessionIDOptions, []BrowserHandle]("browser.List")
 	BrowserClose      = define[SessionIDOptions, None]("browser.Close")
+	// BrowserAnswerDialog answers the JavaScript dialog the page holds open,
+	// and answers with the page as it stands after it.
+	BrowserAnswerDialog = define[BrowserDialogOptions, BrowserPageInfo]("browser.AnswerDialog")
 
 	// The window's side: a pane that shows a session's page and passes the
 	// person's input to it, beside the agent driving the same page.
@@ -31,6 +34,9 @@ var (
 	BrowserKey     = define[BrowserKeyOptions, None]("browser.Key")
 	BrowserText    = define[BrowserTextOptions, None]("browser.Text")
 	BrowserNav     = define[BrowserNavOptions, None]("browser.Nav")
+	// BrowserAnswer is the person answering the page's open dialog in the
+	// pane, the window's side of BrowserAnswerDialog.
+	BrowserAnswer = define[BrowserDialogOptions, None]("browser.Answer")
 	// BrowserSelection is the text selected in the page, which the pane
 	// copies to the system clipboard: the headless browser's own clipboard
 	// is not the person's.
@@ -89,11 +95,42 @@ type BrowserState struct {
 	ByAgent bool   `json:"byAgent"`
 	URL     string `json:"url"`
 	Title   string `json:"title"`
+	// Dialog is the JavaScript dialog the page holds open until the person
+	// or the agent answers it; nil when none is.
+	Dialog *BrowserDialog `json:"dialog,omitempty"`
+}
+
+// BrowserDialog is a JavaScript dialog a session's page opened. Type is
+// Chrome's: alert, confirm, prompt or beforeunload. Default is a prompt's
+// default text; URL is the page that opened it. Answer, on one the person
+// answered, is DialogAccepted or DialogDismissed.
+type BrowserDialog struct {
+	Type    string `json:"type"`
+	Message string `json:"message"`
+	Default string `json:"default,omitempty"`
+	URL     string `json:"url"`
+	Answer  string `json:"answer,omitempty"`
+}
+
+// Dialog answers, as a page answer reports one the person gave.
+const (
+	DialogAccepted  = "accepted"
+	DialogDismissed = "dismissed"
+)
+
+// BrowserDialogOptions answers session ID's open dialog: Accept is OK (Leave
+// on a beforeunload), false is Cancel. Text is what a prompt returns on OK;
+// nil keeps its default text.
+type BrowserDialogOptions struct {
+	ID     string  `json:"id"`
+	Accept bool    `json:"accept"`
+	Text   *string `json:"text,omitempty"`
 }
 
 // BrowserAgentAct is one agent action on its page. Action is click, type,
 // press or scroll at a point; back, forward, reload or navigate, which the
-// pane's toolbar does; or "" for one that changes nothing on screen (reading
+// pane's toolbar does; accept or dismiss, the buttons of the pane's dialog
+// card; or "" for one that changes nothing on screen (reading
 // the page, a screenshot). X and Y are where it acted, in CSS pixels, when it
 // acted at a point; DY is a scroll's distance, positive down; URL is where a
 // navigate went.
@@ -274,6 +311,13 @@ type BrowserPageInfo struct {
 	// counts those past the cap.
 	ConsoleErrors     []string `json:"consoleErrors,omitempty"`
 	ConsoleErrorsMore int      `json:"consoleErrorsMore,omitempty"`
+	// Dialog is the JavaScript dialog the page holds open: until it is
+	// answered (BrowserAnswerDialog) the page runs no script, so the rest of the
+	// answer is the page as it stood when the dialog opened.
+	Dialog *BrowserDialog `json:"dialog,omitempty"`
+	// Dialogs are the ones the person answered in the pane since the agent's
+	// last page answer.
+	Dialogs []BrowserDialog `json:"dialogs,omitempty"`
 }
 
 // BrowserPointOptions is a point of session ID's page, in CSS pixels.

api/testdata/contract.golden

@@ -3,6 +3,8 @@ agentplugin.Status(None) []PluginStatus
 agentplugin.Update(PluginProviderOptions) None
 appupdate.Apply(None) None
 appupdate.Status(None) AppUpdateStatus
+browser.Answer(BrowserDialogOptions) None
+browser.AnswerDialog(BrowserDialogOptions) BrowserPageInfo
 browser.Attach(BrowserViewOptions) BrowserHandle
 browser.Back(SessionIDOptions) None
 browser.Click(BrowserClickOptions) BrowserPageInfo
@@ -311,6 +313,26 @@ AppUpdateStatus {
 	installCommand string
 }
 
+BrowserDialogOptions {
+	id string
+	accept bool
+	text,omitempty *string
+}
+
+BrowserPageInfo {
+	url string
+	title string
+	text string
+	interactive []BrowserInteractive
+	truncated bool
+	downloads,omitempty []BrowserDownload
+	waitTimedOut,omitempty bool
+	consoleErrors,omitempty []string
+	consoleErrorsMore,omitempty int
+	dialog,omitempty *BrowserDialog
+	dialogs,omitempty []BrowserDialog
+}
+
 BrowserViewOptions {
 	id string
 	w int
@@ -336,18 +358,6 @@ BrowserClickOptions {
 	...BrowserTarget
 }
 
-BrowserPageInfo {
-	url string
-	title string
-	text string
-	interactive []BrowserInteractive
-	truncated bool
-	downloads,omitempty []BrowserDownload
-	waitTimedOut,omitempty bool
-	consoleErrors,omitempty []string
-	consoleErrorsMore,omitempty int
-}
-
 BrowserPointOptions {
 	id string
 	x float64
@@ -428,6 +438,7 @@ BrowserState {
 	byAgent bool
 	url string
 	title string
+	dialog,omitempty *BrowserDialog
 }
 
 BrowserScreenshotOptions {
@@ -1761,13 +1772,6 @@ SessionExit {
 	code,omitempty *int
 }
 
-BrowserTarget {
-	index,omitempty *int
-	selector,omitempty string
-	x,omitempty *float64
-	y,omitempty *float64
-}
-
 BrowserInteractive {
 	index int
 	tag string
@@ -1780,6 +1784,21 @@ BrowserInteractive {
 	checked,omitempty *bool
 }
 
+BrowserDialog {
+	type string
+	message string
+	default,omitempty string
+	url string
+	answer,omitempty string
+}
+
+BrowserTarget {
+	index,omitempty *int
+	selector,omitempty string
+	x,omitempty *float64
+	y,omitempty *float64
+}
+
 ProfileUpdate {
 	name,omitempty string
 	color,omitempty *string

docs/browser-tab.md

@@ -72,8 +72,38 @@ where it was thrown, or an error Chrome logs itself, such as a resource that
 failed to load. Each is one line cut to 200 characters; past the first five, a
 `(N more console errors)` line counts the rest. Warnings, info and log
 messages are left out. The text is what the page logs, so a page that logs a
-form's value hands it to the agent; lich reads nothing else. These lines are
-English, outside the prompt-language catalogs, like the rest of the page answer.
+form's value hands it to the agent; lich reads nothing else.
+
+## Dialogs
+
+An `alert`, `confirm`, `prompt` or `beforeunload` the page opens stays open
+until someone answers it, and until then the page runs no script and takes no
+input. lich answers no dialog on its own:
+
+- The pane shows it as a card over the top of the page, naming the site that
+  opened it, with OK and Cancel (Leave and Stay for a `beforeunload`) and a
+  field for a `prompt`. The person answers there.
+- The agent's call that opened it answers at once, rather than hanging, with
+  the page as it stood and a `dialog open:` line; any other call on that page
+  fails with a message naming the dialog. `browser_dialog` (`lich browser
+  dialog accept|dismiss`) answers it, and the pane plays the agent's cursor
+  pressing the card's button. `text` is what a `prompt` returns on OK; left
+  out, it returns its default text.
+- Whichever answers first wins. A dialog the person answered reaches the
+  agent's next page answer as a `dialog answered:` line.
+
+Accepting a `beforeunload` less than a second after it opened waits out the
+rest of that second: Chrome aborts the navigation it held when it is accepted
+sooner, and reloads the page, which asks again.
+
+## Languages of the page answer
+
+The line tags of a page answer (`url:`, `title:`, `wait:`, `text:`,
+`interactive`, `downloaded:`, `downloading:`, `console error:`, `dialog
+open:`, `dialog answered:`) stay English: the tool descriptions name them. The
+prose around them, the element list's legend, the filled and checked marks,
+the note that more elements wait below, and what a held dialog asks of the
+agent, follows the session's prompt language.
 
 ## Downloads
 
@@ -104,5 +134,5 @@ window.
 
 Claude Code, Codex and opencode receive the tools at spawn. Antigravity,
 oh-my-pi, Crush, Cursor CLI and Kiro receive them from the lich MCP server the
-plugin registers. Downloads reach all eight the same way: in the answer of the
-same tools.
+plugin registers. Downloads and dialogs reach all eight the same way: in the
+answer of the same tools, and `browser_dialog` for all of them.

docs/ceilings.md

@@ -1012,6 +1012,18 @@ work when nobody knows it and that the call site never shows. The mechanism and
   pane is not held. A download still running after ten seconds is reported in progress and named again when it
   ends. No tool lists past downloads or cancels one, nothing caps their size, and closing the browser cancels one
   still running.
+- **A dialog a session's page opens holds the page until someone answers it** (`internal/browser/dialogs.go`,
+  `chrome_dialog.go`, `docs/browser-tab.md`): nothing answers it on its own, so an agent that never calls
+  `browser_dialog` and a person who never looks at the pane leave the page frozen, every other agent call failing
+  with the dialog's name, until the browser is closed. The agent's click that opened it answers with the page as it
+  stood, not as the dialog's answer left it. A dialog the page opens on a timer interrupts whichever call is
+  running. Accepting a `beforeunload` less than a second after it opened is held to that second: accepted sooner,
+  Chrome aborts the navigation it held and reloads the page, which asks again (3 of 3 at 300 ms, 3 of 6 at 400 ms,
+  none of 30 from 500 ms; Chrome for Testing 155 and Helium 0.19.2.1). The agent hears of a dialog the person
+  answered, at most twenty between two page answers, but not of one the agent itself answered. A held page cannot lay
+  out, so a pane opened or resized meanwhile shows it at the size it had, and lays it out at the pane's once the
+  dialog closes; a screenshot fails until then.
+  A window opened with Open in a window was not tried with a dialog.
 
 ## Languages
 

internal/browser/actions.go

@@ -70,13 +70,13 @@ func (s *Service) Info(id string) (PageInfo, error) {
 		return e
 	})
 	if err != nil {
-		s.drop(sess)
-		return PageInfo{}, err
+		return PageInfo{}, s.failed(sess, err)
 	}
 	s.remember(sess, info.URL, info.Title)
 	s.agentActed(sess, api.BrowserAgentAct{})
 	info.Downloads = s.untold(sess)
 	info.ConsoleErrors, info.ConsoleErrorsMore = s.consoleUntold(sess)
+	info.Dialogs = s.answeredUntold(sess)
 	return info, nil
 }
 
@@ -96,8 +96,7 @@ func (s *Service) Click(id string, t Target) error {
 		return e
 	})
 	if err != nil {
-		s.drop(sess)
-		return err
+		return s.failed(sess, err)
 	}
 	s.touch(sess)
 	s.agentActed(sess, api.BrowserAgentAct{Action: "click", X: &x, Y: &y})
@@ -165,8 +164,7 @@ func (s *Service) Screenshot(id, dest string) (string, error) {
 		return sess.page.Screenshot(ctx, dest)
 	})
 	if err != nil {
-		s.drop(sess)
-		return "", err
+		return "", s.failed(sess, err)
 	}
 	s.touch(sess)
 	s.agentActed(sess, api.BrowserAgentAct{})
@@ -198,8 +196,7 @@ func (s *Service) goTo(sess *session, u string) error {
 		download, err = s.navigate(ctx, sess, u)
 		return err
 	}); err != nil {
-		s.drop(sess)
-		return err
+		return s.failed(sess, err)
 	}
 	if download {
 		s.touch(sess)
@@ -273,8 +270,7 @@ func (s *Service) drive(id string, fn func(Page, context.Context) error) (*sessi
 	}
 	err = runPage(func(ctx context.Context) error { return fn(sess.page, ctx) })
 	if err != nil {
-		s.drop(sess)
-		return nil, err
+		return nil, s.failed(sess, err)
 	}
 	s.touch(sess)
 	return sess, nil

internal/browser/browser.go

@@ -12,6 +12,7 @@ import (
 	"time"
 
 	"github.com/chromedp/cdproto/network"
+	"github.com/lichdotdev/lich/api"
 )
 
 // idleAfter is how long a headless browser no pane shows sits unused before
@@ -81,8 +82,13 @@ type session struct {
 	// first consoleErrorMax of them; consoleMore counts the rest.
 	consoleErrors []string
 	consoleMore   int
-	page          Page
-	lastUsed      time.Time
+	// dialog is the JavaScript dialog the page holds open; answered are the
+	// ones the person answered since the agent's last page answer.
+	dialog   *api.BrowserDialog
+	dialogAt time.Time
+	answered []api.BrowserDialog
+	page     Page
+	lastUsed time.Time
 }
 
 // New starts a service that launches the system Chromium (chromium.FindBrowser)
@@ -152,8 +158,7 @@ func (s *Service) OpenVisible(owner string) (Handle, error) {
 		return s.promote(sess)
 	}
 	if err := runPage(sess.page.Focus); err != nil {
-		s.drop(sess)
-		return Handle{}, err
+		return Handle{}, s.failed(sess, err)
 	}
 	s.touch(sess)
 	return s.handleOf(sess), nil
@@ -170,8 +175,7 @@ func (s *Service) promote(sess *session) (Handle, error) {
 		cookies, err = sess.page.Cookies(ctx)
 		return err
 	}); err != nil {
-		s.drop(sess)
-		return Handle{}, err
+		return Handle{}, s.failed(sess, err)
 	}
 	s.mu.Lock()
 	s.detachLocked(sess)
@@ -273,7 +277,7 @@ func (s *Service) start(spec launchSpec) (Handle, error) {
 		id: newID(), owner: spec.owner, dir: spec.dir, url: spec.url, headed: spec.headed,
 		byAgent: spec.byAgent, page: page, lastUsed: s.now(),
 	}
-	page.Listen(s.frameSink(sess), s.infoSink(sess), s.downloadSink(sess), s.consoleSink(sess))
+	page.Listen(s.frameSink(sess), s.infoSink(sess), s.downloadSink(sess), s.consoleSink(sess), s.dialogSink(sess))
 	if err := runPage(func(ctx context.Context) error {
 		if len(spec.cookies) > 0 {
 			if err := page.SetCookies(ctx, spec.cookies); err != nil {