Add three test cases covering:
- Immediate match on an already-present element
- Polling match on an element added after a 200ms setTimeout delay
- Timeout error on a non-existent element with a short timeout
Add mcp_wait_for_selector.html test fixture that injects a #delayed
element after 200ms via setTimeout for the polling test.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Adds a waitForSelector tool to the MCP server that polls for a CSS
selector match with a configurable timeout (default 5000ms). Returns the
backendNodeId of the matched element for use with click/fill tools.
The tool runs the session event loop between selector checks, so
dynamically-created elements are found as they appear from JS execution
or network responses.
When running mcp server, it initialized lp.mcp.Server in the main thread
which also implicitly created the V8 isolate in the main thread.
When processing requests (like calling the goto tool) inside mcpThread,
V8 would assert that the isolate doesn't match the current thread.
Fixes#1938
The Context's call_arena should be based on the source, e.g. the IsolateWorld
or the Page, not always the page. There's no rule that says all Contexts have
to be a subset of the Page, and thus some might live longer and by doing so
outlive the page_arena.
Also, on context cleanup, isolate worlds now cleanup their identity.
detachFromTarget and setAutoAttach(false) both null bc.session_id
without notifying the client. Per the CDP spec, detaching a session
must fire a Target.detachedFromTarget event so the driver stops
sending messages on the stale session ID.
Capture the session_id before nulling it and fire the event in both
code paths. Add tests covering the event emission and the no-session
edge case.
Fixes#1819
This contribution was developed with AI assistance (Claude Code + Codex).
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Small tweaks to https://github.com/lightpanda-io/browser/pull/1896
Improve the wait ergonomics with an Option with default parameter. Revert
page pointer logic to original (don't think that change was necessary).
History: We started with 1 context and thus only had 1 identity map. Frames
were added, and we tried to stick with 1 identity map per context. That didn't
work - it breaks cross-frame scripting. We introduced "Origin" so that all
frames on the same origin share the same objects. That almost worked, by
the v8::Inspector isn't bound by a Context's SecurityToken. So we tried 1 global
identity map. But that doesn't work. CDP IsolateWorlds do, in fact, need some
isolation. They need new v8::Objects created in their context, even if the
object already exists in the main context.
In the end, you end up with something like this: A page (and all its frames)
needs 1 view of the data. And each IsolateWorld needs it own view. This commit
introduces a js.Identity which is referenced by the context. The Session has a
js.Identity (used by all pages), and each IsolateWorld has its own js.Identity.
As a bonus, the arena pool memory-leak detection has been moved out of the
session and into the ArenaPool. This means _all_ arena pool access is audited
(in debug mode). This seems superfluous, but it's actually necessary since
IsolateWorlds (which now own their own identity) can outlive the Page so there's
no clear place to "check" for leaks - except on ArenaPool deinit.
js.Origin was added to allow frames on the same origin to share our zig<->js
maps / identity. It assumes that scripts on different origins will never be
allowed (by v8) to access the same zig instances.
If two different origins DID access the same zig instance, we'd have a few
different problems. First, while the mapping would exist in Origin1's
identity_map, when the zig instance was returned to a script in Origin2, it
would not be found in Origin2's identity_map, and thus create a new v8::Object.
Thus we'd end up with 2 v8::Objects for the same Zig instance. This is
potentially not the end of the world, but not great either as any zig-native
data _would_ be shared (it's the same instance after all), but js-native data
wouldn't.
The real problem this introduces though is with Finalizers. A weak reference
that falls out of scope in Origin1 will get cleaned up, even though it's still
referenced from Origin2.
Now, under normal circumstances, this isn't an issue; v8 _does_ ensure that
cross-origin access isn't allowed (because we set a SecurityToken on the
v8::Context). But it seems like the v8::Inspector isn't bound by these
restrictions and can happily access and share objects across origin.
The simplest solution I can come up with is to move the mapping from the Origin
to the Session. This does mean that objects might live longer than they have to.
When all references to an origin go out of scope, we can do some cleanup. Not
so when the Session owns this data. But really, how often are iframes on
different origins being created and deleted within the lifetime of a page?
When Origins were first introduces, the Session got burdened with having to
manage multiple lifecycles:
1 - The page-surviving data (e.g. history)
2 - The root page lifecycle (e.g. page_arena, queuedNavigation)
3 - The origin lookup
This commit doesn't change that, but it makes the session responsible for
_a lot_ more of the root page lifecycle (#2 above).
I lied. js.Origin still exists, but it's a shell of its former self. It only
exists to store the SecurityToken name that is re-used for every context with
the same origin.
The v8 namespace leaks into Session.
MutationObserver and IntersectionObserver are now back to using weak/strong refs
which was one of the failing cases before this change.
We now pay attention to the type of event that causes the unhandled exception.
This allows us to trigger the window.rejectionhandled event when that is the
correct type. It also lets us no-op for other event types which should not
trigger rejectionhandled or unhandledrejection.
Fixes stackoverflow in github integration.
- Refactor `wait` and `_wait` to handle `page` as `*Page` instead of `**Page`, preventing stale references during navigations.
- Update `networkidle` wait condition to use `_notified_network_idle == .done`.
- Document `--wait_ms` and `--wait_until` options in `Config.zig` help text.
