Verifying the AntHill client against the running app

AntHill.Client is WPF + BlazorWebView. bUnit cannot reproduce its router or its input path, so UI truth claims must be checked against the running window.

1. Launch with a debugging port and attach

hub start application=src/AntHill.Client/bin/Debug/net10.0-windows10.0.19041.0/win-x64/AntHill.Client.exe
     env={"WEBVIEW2_ADDITIONAL_BROWSER_ARGUMENTS": "--remote-debugging-port=9223"}

Then in eval, a one-shot CDP call per request (the socket does not survive between eval calls):

const cdp = async (method, params = {}) => {
  const list = await (await fetch("http://localhost:9223/json/list")).json();
  const t = list.find(x => x.type === "page");          // url is https://0.0.0.1/
  return await new Promise((res, rej) => {
    const ws = new WebSocket(t.webSocketDebuggerUrl);
    ws.onopen = () => ws.send(JSON.stringify({ id: 1, method, params }));
    ws.onmessage = m => { const d = JSON.parse(m.data); if (d.id === 1) { ws.close(); res(d.result ?? d.error); } };
    setTimeout(() => rej(new Error("timeout")), 10000);
  });
};
const js = async e => (await cdp("Runtime.evaluate", { expression: e, returnByValue: true, awaitPromise: true })).result?.value;

• In-app navigation: history.pushState({}, '', '/settings'); dispatchEvent(new PopStateEvent('popstate')) (location.href = … reloads the host page instead).
• Screenshot a bar: cdp("Page.captureScreenshot", { clip: { x, y, width, height, scale: 2 } }), write the base64 to a png under _diag/, read it. .gitignore covers t-*.log and _diag/, not images, so delete any png written anywhere else.
• Client boot to first paint is ~10s on a real catalogue. Sample on a loop rather than sleeping once, or you will attribute the wrong state to the wrong moment.

2. Force a real outage rather than trusting a unit test

Settings live at %LOCALAPPDATA%\BigAntStudios\AntHill\settings.json (NOT %LOCALAPPDATA%\AntHill, which is the Velopack install and is wiped on update; see ClientPaths).

{ "ServerUrl": "http://localhost:5252", "IsConfigured": true }

Back it up, repoint at a dead port, relaunch, observe, restore, verify by reading the file back. This is the only way to see the offline branch of any status UI.

3. Mouse side buttons

They need real OS input, because CDP-synthesised events bypass the layer under test. For the hook, the mouse_event codes and the contamination check, see webview2-wpf-input-and-history.

4. Two traps that make the client show stale truth

Silent-null unreachability. CatalogueSync.RefreshIfChangedAsync returns null when the server cannot be reached, deliberately, because the local copy is still usable. Any status UI reading fetch outcomes therefore sees no failure and reports "connected" through an outage. Read CatalogueSync.LastContact (written by every path that speaks to the server, including the manual sync button) instead.

Retained query parameters. Blazor writes a [SupplyParameterFromQuery] property only when the key is present in the address. Same-route navigation reuses the page instance, so the property keeps its previous value: /source-control?asset=X then a bare /source-control left the "this asset" panel live on the old asset. Parse the query out of Nav.Uri each render instead. bUnit re-supplies parameters and cannot reproduce this; do not write a bUnit "regression test" for it, since it passes with the fix stashed. Verify in the running client.

5. Test gate

For MSB3026/3027/3021 with "locked by: AntHill.Web / Microsoft Visual Studio" (a file lock: the suite never ran), see anthill-shared-css-verify.