E2E.Engine

API reference

Public types in the E2E.Engine namespace.

Classes

Type	Summary
AppLogEntry	One line of what the app did on its own, as an engine reports it to AppLog (upstream’s AppLogEntry): console output, an exception nothing caught, a failed request. The harness redacts and bounds it.
BoundingBox	A viewport-relative rectangle in CSS pixels.
BrowserCookie	A browser cookie. When setting one, give either Url, or Domain with an optional Path, never both.
BrowserDownload	A download the browser saved as an artifact of the attempt (upstream’s waitForDownload result, { path, absolutePath, suggestedFilename }).
BrowserDownloadContext	Handed to ReadAsync, once per file.
BrowserLease	One leased browser, as CancellationToken) returns it and CancellationToken) gets it back. A provider may derive from it and keep further fields: release gets that same object, while only the declared fields travel from the runner to the worker that attaches to it.
BrowserProviderDownloads	How a download reaches the runner from a browser on another machine. The browser saves every file to its own disk, where the runner cannot open it, so the engine points the browser’s downloads at Dir there and reads each finished file back through ReadAsync.
BrowserReleaseContext	Handed to release, once per lease.
BrowserRequest	What the engine asks a provider for: one browser for one worker slot, or for one attempt, of a run.
BrowserResponse	A response an engine observed, with its body still being read.
Dialog	A native dialog as a test’s handler sees it (upstream’s Dialog).
DialogHandler	What answers a native dialog (upstream’s DialogHandler): Accept, Dismiss, or a function that must call AcceptAsync(string) or DismissAsync() before it returns.
DocumentElement	A mutable control on a DocumentPage.
DocumentEngine	In-memory page engine for samples and tests that do not need a browser. Each open builds a fresh page from the route mapped on DocumentWorld. Actions mutate that page until the next open. app.back rebuilds the previous route, and app.restart and app.clearState drop the history and reopen the base URL. The document engine has no browser, so the Browser fixture is unsupported.
DocumentPage	One in-memory screen. Builder methods append controls in reading order.
DocumentWorld	Routes a DocumentEngine can open. Each open builds a new page from the mapped factory.
EngineFinishInfo	The facts handed to an engine’s finish (CancellationToken)), once per run and target after the last worker is gone, with the cleanup budget of one hook. Upstream’s EngineFinishInfo.
EngineFixtureContext	What an engine’s fixture gets from the attempt, once per attempt. Upstream’s EngineFixtureContext, of which the port has locator only: its fixtures take their own cancellation tokens, and record no steps of their own yet.
EngineInitInfo	What a worker’s init is given, once per worker, before its first attempt. Upstream’s EngineInitInfo.
EnginePrepareInfo	The facts handed to an engine’s prepare (CancellationToken)), once per run and target in the runner process, before any worker exists. Upstream’s EnginePrepareInfo.
EnginePrepareResult	What prepare learned that the run must honour. Upstream’s EnginePrepareResult.
EngineScreenshot	A captured viewport: PNG bytes, and how many image pixels one viewport (CSS) pixel takes.
EngineStartOptions	Passed to CancellationToken) once per test attempt.
KeyModifiers	The names of KeyModifier, which a recorded action and an MCP argument spell. Upstream’s KEYMODIFIERS and isKeyModifier.
LocatorAction	A deterministic action CancellationToken) carries out on one node.
LocatorAction.Check
LocatorAction.Clear
LocatorAction.DoubleTap	A double tap. Modifiers are held for both clicks, as for LocatorAction.Tap.
LocatorAction.Fill
LocatorAction.Focus
LocatorAction.Press
LocatorAction.PressSequentially	Focuses the node and types Text one character at a time.
LocatorAction.ScrollIntoView	Scrolls the node’s nearest scrollable container until the node is in the viewport.
LocatorAction.Select
LocatorAction.Swipe	Scrolls a scrollable node about three quarters of its height or width. The viewport swipe is CancellationToken).
LocatorAction.Tap	A tap. Modifiers are held for the click, and only an engine that declares TapModifiers receives them.
LocatorAction.Uncheck
NodeStates	Boolean states a platform can report for one node.
Observation	A redacted semantic snapshot of the current screen.
ObservationLimits	Limits from the engine contract. Engines cut names and text before they reach the model.
ProviderRecordContext	Handed to a provider’s RecordAsync, once per attempt that records video.
ProviderRecording	A recording a provider’s service makes of the browser or device it leased, as RecordAsync started it.
ProviderRecordingResult	What a stopped recording became: a file the provider wrote into the directory it was given, by name (File), or a recording its service keeps, by http(s) URL and media type (Url and MediaType).
ProviderRecordings	The recording seam every engine’s provider shares (upstream recording.ts): a hosted browser or device service recording the attempt itself, in place of the engine’s own capture. A provider’s RecordAsync starts a ProviderRecording for the lease the attempt rides; CancellationToken) ends it and checks what the provider handed back, so every engine turns a recording into a VideoSegment the same way.
ProviderRecordingStopContext	Handed to CancellationToken), once per recording.
ProviderRecordingTarget	Where the attempt’s recording lands and who made it, for CancellationToken).
RouteContinueOverrides	What ContinueAsync(RouteContinueOverrides) changes about the request before it goes to the network.
RouteFulfillResponse	How FulfillAsync(RouteFulfillResponse) answers a request. Give at most one of Json, Body, or Path; none is an empty body.
SemanticNode	One node of an observation tree. Ref is valid only for the observation it came from.
VideoFile	A video file in the attempt artifact directory.
VideoLink	A recording a hosted service keeps, by URL: the report links to it and the runner never downloads it.
VideoSegment	One recorded video of an attempt: a file the engine wrote into the attempt artifact directory (VideoFile), or a recording a hosted service keeps and links to (VideoLink).
WebBasicAuth	HTTP basic authentication the browser answers a 401 challenge with.
WebConnectOptions	Attach to a remote Chromium over CDP instead of launching one. Supplying ReconnectEndpoint opts into a persistent context instead.
WebEngine	Browser engine for the web target. It drives Chromium through Playwright, reads a semantic tree (role, name, text, test id, state), and performs the same node actions the document engine does. Install browsers once with playwright.ps1 install chromium from this project’s build output.
WebEngineOptions	Options of the browser engine: how it drives the app.
WebInitScript	A script every document runs before the page’s own, in every tab and frame: JavaScript source, a file of it, or a function source the page calls. A string converts to source.
WebMedia	User preferences a page reads through @media rules and matchMedia, as Playwright’s emulateMedia sets them. A feature left null keeps the browser’s own value, or the one an earlier call set.
WebRouteRequest	The request a route intercepted.
WebScreencastOptions	How the engine’s own screencast of the page records an attempt that records video: the frame size and the JPEG quality of the frames it encodes. Which attempts record is the config’s video, not an engine option. Upstream’s WebScreencastOptions.
WebViewport	A page size in CSS pixels.

Interfaces

Type	Summary
IBrowserProvider	A source of hosted browsers: the seam a hosted browser service plugs into (upstream BrowserProvider). In Worker scope CancellationToken) is called once per worker slot, for every slot at once, in the runner; a worker whose browser drops calls it again, from its own process, for a replacement. In Attempt scope every attempt start calls it from the worker. CancellationToken) is called exactly once per lease, by the process that acquired it, also after an acquire of another slot failed; a worker that dies first never calls it, and CancellationToken) releases what it left. A provider must not rely on runner-process state to serve a request from a worker. Nothing here knows any vendor.
IBrowserRoute	One intercepted request, as an engine hands it to a route handler. The harness has already validated each decision and takes at most one.
IBrowserSession	The browser-shaped surface an engine session can add on top of IEngineSession. The Browser fixture uses it, and fails with UNSUPPORTEDCAPABILITY when the session does not implement it. The harness has already validated every argument.
IEngine	The body of one target. Core knows this contract and never an engine’s internals. Version is the engine version. It is not part of the replay cache key: a recording re-finds its nodes at replay.
IEngineFixtureHost	An engine session that contributes a fixture, which the harness tells about the attempt when it starts. .NET-only: upstream’s engine declares fixtures, factories the harness calls with an EngineFixtureContext; the port’s session builds its own fixture (Device), so this hands it the context.
IEngineSession	One attempt’s session with the app. Disposed at the end of the attempt, after afterEach.
IPreparableEngine	An engine with upstream’s optional prepare and finish hooks (declared in engine/index.ts): what a run provisions once per target before any worker starts, such as a hosted device, and gives back after the last worker ended, so the provisioning happens once per run instead of per worker. The port has no test runner that calls them: a host that starts the engine on its own, as e2e explore and e2e mcp do, calls them around the one attempt (upstream’s openStandaloneAttempt), prepare when the session opens and finish when it closes, on every path; the mobile adapters’ MobileAppTest runs them once per test process. .NET-only name: upstream tests the engine handle for the members. WebEngine does not implement it, because it leases for the attempt it starts.

Enums

Type	Summary
BrowserProtocol	The protocol a leased browser’s endpoint speaks. .NET-only: upstream’s lease always carries a CDP endpoint.
BrowserProviderScope	How long a lease lives. Worker (the default) is one browser per worker slot, acquired in prepare and released in finish. Attempt is a fresh browser per attempt, acquired when the attempt starts and released when it ends, reconnected through the lease’s ReconnectEndpoint after a transport drop.
DialogType	The kind of a native dialog, independent of its message (upstream’s Dialog[‘type’]).
EngineCapabilities	Capabilities the harness reads off an engine. An engine never calls a model.
KeyModifier	A key held for a click, as a Shift-click extends a selection. Upstream’s KeyModifier (engine/contract.ts). ControlOrMeta is Control, or Meta on macOS.
Momentum	Fling strength of a swipe: how far the gesture travels. Upstream’s Momentum (none, slow, fast).
ScrollDirection	Which way a scroll moves the content into view. Down reveals what is below.
WebColorScheme	The prefers-color-scheme a page reports.
WebReducedMotion	The prefers-reduced-motion a page reports.