decoder reconnect

CHANGELOG.md

@@ -11,6 +11,7 @@ The application version is maintained in `package.json` and displayed in the adm
 - Personal mobile profiles show last successful data retrieval, stale-data and failed-update warnings, and a Retry button without replacing loaded statistics or active forms. Requests time out after 15 seconds and cannot overlap.
 - Browser coverage for Race Day start/pause/resume/finish and switching to the next queued heat, against a simulated decoder socket.
 - Browser coverage for opening the OBS overlay as a real popup window (not a direct URL load): compact layout, and live clock updates that freeze on pause, polling independently of the admin page.
+- Browser coverage for decoder auto-reconnect after a dropped socket (simulated network interruption): reconnects onto exactly one connection, never a duplicate, and stops retrying once auto-reconnect is turned off.
 
 ### Fixed
 

ROADMAP.md

@@ -56,10 +56,12 @@ Acceptance: each configured channel distinguishes an open socket from actual rec
 - [x] Add a bounded live message sample/log with pause, clear and copy controls.
 - [x] Show why an incoming passing was ignored or rejected without changing lap validation.
 - [x] Add simulated-socket tests for receiving, parsing, disconnecting and open status.
-- [ ] Verify automatic reconnect against a real decoder/network interruption.
+- [x] Verify automatic reconnect against a simulated decoder/network interruption (raw socket drop, not a clean close), checking for duplicate connections and correct reconnect-timer behavior.
 - [x] Document IP/port/channel setup and the difference between decoder connection and incoming data.
 
-Verified 2026-09-08: 128 logic/API tests and browser smoke tests passed, including mobile profile retention during network loss and recovery via Retry. Real decoder/network reconnect remains a hardware check.
+Verified 2026-09-08: 128 logic/API tests and browser smoke tests passed, including mobile profile retention during network loss and recovery via Retry.
+
+Verified 2026-09-09: a browser test (`tests/browser_decoder_reconnect.js`) drops a real TCP connection to a simulated decoder socket and confirms the frontend detects it, waits for the ~2s reconnect timer in `src/decoder_runtime.js`, and settles on exactly one live connection afterward - never two at once. Disabling auto-reconnect through the real Settings form (not a raw state patch, which never reaches an already-loaded page) correctly stops further retries after a drop. Reconnecting against physically real AMMC hardware remains a separate hardware-in-the-loop check this suite cannot cover.
 
 ## 3. Clearer practice follow-up
 

tests/browser_decoder_reconnect.js

@@ -0,0 +1,59 @@
+import assert from "node:assert/strict";
+import { startFakeDecoder } from "./browser_fake_decoder.js";
+
+export async function runDecoderReconnectSmoke({ evaluate, navigate, savedState, waitFor, pause, base }) {
+  const patchState = async patch => {
+    const current = await savedState();
+    Object.assign(current, patch);
+    const response = await fetch(base + "/api/state", { method: "POST", headers: { "Content-Type": "application/json" }, body: JSON.stringify(current) });
+    assert.equal(response.ok, true);
+  };
+  const badgeOnline = () => evaluate('document.getElementById("connectionBadge")?.classList.contains("badge-online")');
+
+  const decoder = await startFakeDecoder();
+  try {
+    const seeded = await savedState();
+    await patchState({ settings: { ...seeded.settings, autoReconnect: true, wsUrl: `ws://127.0.0.1:${decoder.port}` } });
+
+    await navigate("events", "eventForm");
+    await waitFor(async () => await badgeOnline(), "decoder connects on page load");
+    assert.equal(decoder.activeConnections(), 1, "exactly one live connection after the initial connect");
+    assert.equal(decoder.totalConnections(), 1, "a clean initial connect makes exactly one connection attempt");
+
+    // Simulate a real network/decoder interruption: drop the TCP connection with a raw
+    // reset rather than a clean WS close handshake, the way a lost cable or a decoder
+    // power-cycle actually would - see src/decoder_runtime.js's wsClient.onclose.
+    decoder.dropConnections();
+    await waitFor(async () => (await badgeOnline()) === false, "badge shows offline once the drop is detected");
+    assert.equal(decoder.activeConnections(), 0, "no lingering connection right after the drop");
+
+    // decoder_runtime.js schedules exactly one reconnect attempt 2000ms after onclose.
+    await waitFor(async () => decoder.totalConnections() >= 2, "a reconnect attempt reaches the decoder socket");
+    await waitFor(async () => await badgeOnline(), "badge shows online again after auto-reconnect");
+    assert.equal(decoder.totalConnections(), 2, "auto-reconnect made exactly one new connection attempt, not several");
+    assert.equal(decoder.activeConnections(), 1, "auto-reconnect settles on exactly one live connection, not a duplicate");
+    console.log("PASS decoder auto-reconnects after a dropped socket onto exactly one connection");
+
+    // A second drop must not leave a stray reconnect timer running once autoReconnect is
+    // turned off - the retry loop should stop, not silently keep firing in the background.
+    // Toggling it through the real Settings form (not a raw state patch) matters here:
+    // a raw backend patch never reaches this already-loaded page's in-memory state, only
+    // a fresh navigation would, and that would also drop and reopen the live connection.
+    await navigate("settings", "settingsForm");
+    await waitFor(async () => await badgeOnline(), "decoder is connected on the settings page");
+    await evaluate('document.querySelector("#settingsForm [name=autoReconnect]").checked = false');
+    await evaluate('document.getElementById("settingsForm").requestSubmit()');
+    const connectionsBeforeDrop = decoder.totalConnections();
+    decoder.dropConnections();
+    await waitFor(async () => (await badgeOnline()) === false, "badge shows offline after the second drop");
+    await pause(3000);
+    assert.equal(decoder.totalConnections(), connectionsBeforeDrop, "no reconnect attempt is made once autoReconnect is disabled");
+    assert.equal(await badgeOnline(), false, "stays offline with autoReconnect disabled");
+    assert.equal(decoder.activeConnections(), 0, "no duplicate or stray connection appears while disabled");
+    console.log("PASS disabling auto-reconnect stops further reconnect attempts after a drop");
+  } finally {
+    const cleanup = await savedState();
+    await patchState({ settings: { ...cleanup.settings, autoReconnect: false } });
+    await decoder.close();
+  }
+}

tests/browser_fake_decoder.js

@@ -21,7 +21,9 @@ export async function startFakeDecoder() {
   // plain server.close() would wait forever for them to end; track and destroy them
   // explicitly instead. closeAllConnections() does not reach upgraded sockets.
   const sockets = new Set();
+  let totalConnections = 0;
   server.on("upgrade", (req, socket) => {
+    totalConnections += 1;
     sockets.add(socket);
     socket.on("close", () => sockets.delete(socket));
     const key = req.headers["sec-websocket-key"];
@@ -32,6 +34,12 @@ export async function startFakeDecoder() {
   await new Promise((resolve, reject) => { server.once("error", reject); server.listen(port, "127.0.0.1", resolve); });
   return {
     port,
+    activeConnections: () => sockets.size,
+    totalConnections: () => totalConnections,
+    // Drops every currently-open socket with a raw TCP reset (not a clean WS close
+    // handshake) to simulate a decoder/network interruption, while the server keeps
+    // listening so the frontend's own reconnect logic has somewhere to reconnect to.
+    dropConnections: () => { for (const socket of sockets) socket.destroy(); },
     close: () => new Promise(resolve => {
       for (const socket of sockets) socket.destroy();
       server.close(() => resolve());

tests/browser_smoke.js

@@ -2,6 +2,7 @@ import { runOverlaySmoke } from "./browser_overlays.js";
 import { runRaceSetupSmoke } from "./browser_race_setup.js";
 import { runRaceDaySmoke } from "./browser_race_day.js";
 import { runObsPopupSmoke } from "./browser_obs_popup.js";
+import { runDecoderReconnectSmoke } from "./browser_decoder_reconnect.js";
 import assert from "node:assert/strict";
 import { spawn } from "node:child_process";
 import { existsSync, mkdtempSync, rmSync } from "node:fs";
@@ -134,6 +135,7 @@ try {
   await runRaceSetupSmoke({ evaluate, navigate, fill, savedState, waitFor, pause });
   await runRaceDaySmoke({ evaluate, navigate, fill, savedState, waitFor, pause, base, dialogs });
   await runObsPopupSmoke({ evaluate, navigate, fill, savedState, waitFor, pause, base, debugPort, dialogs, realClick });
+  await runDecoderReconnectSmoke({ evaluate, navigate, savedState, waitFor, pause, base });
   await navigate("classes", "classForm");
   await send("Network.emulateNetworkConditions", { offline: true, latency: 0, downloadThroughput: -1, uploadThroughput: -1 });
   await fill("classForm", { name: "Offline Draft" });