decoder reconnect

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();
+  }
+}