LiveTest API
LiveTest is the runtime control surface for real Fission hosts. It lets tests and manual QA drive the current frame without calculating coordinates by hand. Native hosts expose /health and /cmd; Web test builds expose the same command contract through Chromium.
Enable the server by launching an app with FISSION_TEST_CONTROL_PORT.
FISSION_TEST_CONTROL_PORT=9876 cargo run -p counter
Then check readiness:
curl -s http://127.0.0.1:9876/health
Command shape
All commands go to POST /cmd with JSON.
curl -s http://127.0.0.1:9876/cmd -H 'content-type: application/json' -d '{"cmd":"GetTree"}'
Prefer LiveTestClient in Rust tests and curl for quick manual QA or screenshot capture.
For Web, build and serve the application with fission test --target web, or set FISSION_WEB_TEST_CONTROL=1 on the command that compiles the WASM application, then connect to the served URL. This is a compile-time switch: setting it only while serving the already-built files or while running the Rust browser test does not install the bridge. Rebuild the WASM output after changing it.
FISSION_WEB_TEST_CONTROL=1 ./platforms/web/build-wasm.sh
Ordinary production Web builds deliberately omit globalThis.__FISSION_TEST__.
Then use the browser client:
use fission_test_driver::{BrowserTestOptions, LiveTestClient};
let client = LiveTestClient::launch_browser(
BrowserTestOptions::new("http://127.0.0.1:8123/platforms/web/")
.fission_canvas(),
)?;
client.pump()?;
client.assert_text_visible("Ready")?;
client.simulate_resize(390, 844)?;
let narrow_png = client.capture_screenshot_png()?;
client.simulate_resize(1280, 900)?;
Web screenshots are composited Chromium page captures. The initial driver does not claim Firefox/WebKit coverage or trusted browser clipboard, file, accessibility, and IME event coverage.
For any website, including a Fission Static site or SSR application, use the
same client API with website mode. This needs no test bridge and works with
ordinary rendered HTML, including real server navigation and browser session
cookies:
let client = LiveTestClient::launch_browser(
BrowserTestOptions::new("http://127.0.0.1:3000/sign-in").website(),
)?;
client.fill_text_semantic_identifier("sign-in.email", "[email protected]")?;
client.tap_selector(SelectorQuery::role_label("button", "Sign in"))?;
client.wait_for_text("Welcome", 5_000)?;
Website mode uses standard HTML labels, accessible roles, element ids and
data-testid attributes. It also understands Fission semantic identifiers when
present. It drives Chromium through the test process and does not add a remotely
accessible test endpoint to the application.
Keep this client alive to resize the same page while retaining app state and
route. Enable Web test control on the compiling command, for example
FISSION_WEB_TEST_CONTROL=1 ./platforms/web/build-wasm.sh, and serve the build
through the existing fission serve-web --project-dir . helper or your test host.
Resize uses CSS pixels, preserves the configured device scale and mobile mode
(scale 1 and desktop mode by default), validates dimensions, and waits
for actual viewport/canvas/submitted-layout frame dimensions and paint within
the options timeout (capped at 60 seconds). A changed size must advance the
frame acknowledgement; repeating the same size verifies the current frame.
Raw Web bridge SimulateResize explicitly fails because it lacks host control.
On failure inspect observed state and retry after repair, or drop/relaunch a
closed client. Plain DOM mode (BrowserTestOptions::new(url)) remains the
minimal host-resize and screenshot mode. Use .website() when the test needs
semantic selectors, form interaction, navigation or text assertions on any
rendered website.
See SimulateResize
for limits and recovery. Inspect narrow and wide PNG content after checking
dimensions.
Selector-driven actions
curl -s http://127.0.0.1:9876/cmd -H 'content-type: application/json' -d '{"cmd":"TapSelector","query":{"selector":{"kind":"semantic_identifier","identifier":"settings.save"}}}'
Selectors can target semantic identifiers, explicit widget ids, labels, role plus label, test/accessibility identifiers, duplicate indexes, and scopes.
Screenshots
curl -s http://127.0.0.1:9876/cmd -H 'content-type: application/json' -d '{"cmd":"Screenshot","path":".artifacts/manual/settings.png"}'
Use Screenshot to save a file on the app host. Use CaptureScreenshot when the caller needs the PNG bytes returned as base64 for a custom QA tool. Screenshots are used for visual QA, store assets, and golden comparisons.
See LiveTest commands for the complete reference.
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