Health box and summary update as each WAN check ends (closes #206)

The health box and the summary were drawn only once every check in a
round had ended, so a target that never answers held them back until
its timeout, after the rows already showed the network was back. tick
now redraws both with each WAN host's row. The "Health:" debug log line
moved from updateHealthBox to the end of the round, so it is still
written once per round.

Model: opus-5-5

README.md

@@ -107,6 +107,9 @@ Below it, a summary line covers the WAN hosts only:
   history
 - `Checks`: the rounds run since the page loaded or the interval changed
 
+The health box and the summary take in a WAN host's result as soon as its row
+shows it.
+
 When no WAN host answers, the page checks 4 of them, picked at random, every
 half second. As soon as one answers, a new round starts.
 
@@ -363,7 +366,8 @@ The page is built with Vite and Tailwind CSS v4. All its code is in
 - `HostState` and `AppState`: one host's history and status, and the whole
   page's state.
 - `measureLatency`: one check. `tick`: one round, which checks every host in
-  parallel and draws each row as soon as its check ends.
+  parallel. It draws each row as soon as its check ends, and with a WAN host's
+  row also the summary and the health box.
 - `SparklineRenderer`: the graphs. `buildUI`, `updateHostRow`, `updateSummary`
   and `updateHealthBox`: the page and its parts.
 - `Reporter`: builds and posts the reports. `buildReport` is a pure function of

test/unit/main.test.js

@@ -831,6 +831,44 @@ test("once every WAN target's check has failed, the summary's Reachable slot rea
     assert.equal(elements["#summary-reachable"].className, "text-red-400");
 });
 
+// The network has just come back: every WAN target's last check failed, so
+// the health box reads OFFLINE. In this round every WAN target but one
+// answers after 10ms, and the one never answers. Each element of the summary
+// and the health box is a plain object, as in the tests above; the debug
+// log's panel is not there.
+test("at a 30000ms interval, the summary and the health box take in each WAN target's answer while another WAN target's check is still waiting", async (t) => {
+    CONFIG.updateInterval = 30000;
+    t.mock.method(globalThis.document, "getElementById", (id) =>
+        id.startsWith("summary-") || id.startsWith("health-")
+            ? (elements[`#${id}`] ??= {})
+            : null,
+    );
+    const state = new AppState([]);
+    for (const host of state.wan) {
+        host.pushSample(Date.now(), { latency: null, error: "timeout" });
+    }
+    const silent = state.wan[0];
+    mockTargets(t, (url) => (url === silent.url ? Infinity : 10));
+    // The third tick, as in the tests above.
+    state.tickCount = 2;
+
+    const round = tick(state, new AbortController().signal);
+    t.mock.timers.tick(10);
+    assert.equal(await settled(round), "still waiting");
+    assert.equal(elements["#health-text"].textContent, "HEALTHY");
+    assert.equal(
+        elements["#summary-reachable"].textContent,
+        `${state.wan.length - 1}/${state.wan.length}`,
+    );
+    assert.equal(elements["#summary-max"].textContent, "10");
+    // Checks counts finished rounds only.
+    assert.equal(elements["#summary-checks"].textContent, 2);
+
+    t.mock.timers.tick(CONFIG.requestTimeout - 10);
+    assert.notEqual(await settled(round), "still waiting");
+    assert.equal(elements["#summary-checks"].textContent, 3);
+});
+
 // In the next two tests each of the header's clocks is a plain object, made
 // the first time updateClocks looks it up and kept in elements under "#" and
 // its id.

web/src/main.js

@@ -1126,11 +1126,6 @@ function updateHealthBox(state) {
     el.textContent = labels[health];
     el.className = textColors[health];
     box.className = `mt-4 p-3 rounded-lg border font-mono text-sm text-center ${boxColors[health]}`;
-
-    if (health === "offline" || health === "degraded")
-        log.warning(`Health: ${labels[health]}`);
-    else if (health === "slow") log.warning(`Health: ${labels[health]}`);
-    else if (health === "healthy") log.notice(`Health: ${labels[health]}`);
 }
 
 // Writes the local time, with its time zone's name, and the UTC time into
@@ -1301,12 +1296,13 @@ export async function tick(state, signal, onOffline) {
 
     log.debug(`Tick #${state.tickCount + 1} started`);
 
-    // Each host's row shows its result as soon as its check ends. The
-    // result is discarded if by then the user has paused or the next round
-    // has given up this one's checks, and in the first tick (tickCount is
-    // still 0), which is discarded as a whole below. The row is looked up
-    // when the check ends, as a pin click may have re-sorted the rows since
-    // the round started.
+    // Each host's row shows its result as soon as its check ends, and a WAN
+    // host's result goes into the summary and the health box at the same
+    // time. The result is discarded if by then the user has paused or the
+    // next round has given up this one's checks, and in the first tick
+    // (tickCount is still 0), which is discarded as a whole below. The row
+    // is looked up when the check ends, as a pin click may have re-sorted
+    // the rows since the round started.
     await Promise.all(
         state.allHosts.map(async (host) => {
             const r = await measureLatency(host.url, signal, host.method);
@@ -1316,6 +1312,10 @@ export async function tick(state, signal, onOffline) {
             logCheck(host, r);
             host.pushSample(ts, r);
             updateHostRow(host, state.allHosts.indexOf(host));
+            if (state.wan.includes(host)) {
+                updateSummary(state);
+                updateHealthBox(state);
+            }
             log.debug(`${host.name}: ${r.error ? r.error : r.latency + "ms"}`);
         }),
     );
@@ -1342,9 +1342,15 @@ export async function tick(state, signal, onOffline) {
         sortAndRebuildWAN(state);
     }
 
+    // Redraw the summary and the health box: a pause greys them out too, and
+    // Checks now counts this round.
     updateSummary(state);
     updateHealthBox(state);
 
+    const health = state.healthStatus();
+    if (health === "healthy") log.notice("Health: HEALTHY");
+    else log.warning(`Health: ${health.toUpperCase()}`);
+
     const reachable = state.allHosts.filter(
         (h) => h.status === "online",
     ).length;