fix(server): count keepalive ping as client activity (#17)

server/package.json

@@ -31,6 +31,7 @@
         "export-frontend-graphics": "tsx src/scripts/exportFrontendOptimizedGraphics.ts",
         "export-frontend-maps": "tsx src/scripts/exportFrontendOptimizedMaps.ts",
         "export-client-objs": "tsx src/scripts/exportClientObjs.ts",
+        "test:client-activity": "tsx src/scripts/testClientActivityPolicy.ts",
         "start": "node dist/server.js",
         "lint": "eslint './src/**/*.ts'",
         "world-map": "node scripts/build-world-map.cjs",

server/src/scripts/testClientActivityPolicy.ts

@@ -0,0 +1,41 @@
+import assert from "node:assert/strict";
+import { readFileSync } from "node:fs";
+import { resolve } from "node:path";
+
+const source = readFileSync(resolve(process.cwd(), "src/server.ts"), "utf8");
+const start = source.indexOf("function trackClientActivity");
+const end = source.indexOf("\n}\n\n(async () => {", start);
+
+assert.ok(start >= 0 && end > start, "trackClientActivity must remain present");
+
+const fn = source.slice(start, end + 2);
+const pingMatch = fn.match(/if \(isPingPacket\) \{([\s\S]*?)\n    \}/);
+assert.ok(pingMatch, "ping branch must remain explicit");
+
+const pingBranch = pingMatch[1];
+assert.match(fn, /ws\.packetCount = Number\(ws\.packetCount \?\? 0\) \+ 1;/, "all packets increment packetCount");
+assert.match(pingBranch, /ws\.lastActivityAt = now;/, "ping must refresh client liveness");
+assert.match(pingBranch, /return;/, "ping must return before non-ping accounting");
+
+for (const forbidden of [
+    "lastPacketAt",
+    "packetCountNonPing",
+    "recentPacketTimestamps",
+    "recentPacketIntervalsMs",
+    "packetTypeCounts",
+]) {
+    assert.ok(!pingBranch.includes(forbidden), `ping must not mutate non-ping metric: ${forbidden}`);
+}
+
+const pingBlockEnd = fn.indexOf("}", fn.indexOf("if (isPingPacket)"));
+const nonPingTail = fn.slice(pingBlockEnd + 1);
+assert.match(nonPingTail, /ws\.lastPacketAt = now;/, "non-ping packets still refresh lastPacketAt");
+assert.match(nonPingTail, /ws\.lastActivityAt = now;/, "non-ping packets still refresh activity");
+
+const idleStart = source.indexOf("function processIdleCharactersTick");
+const idleEnd = source.indexOf("\n}\n\nfunction getScoutIdleReferenceAt", idleStart);
+assert.ok(idleStart >= 0 && idleEnd > idleStart, "idle sweep must remain present");
+const idleFn = source.slice(idleStart, idleEnd + 2);
+assert.match(idleFn, /client\.lastActivityAt/, "idle cleanup must continue to use lastActivityAt");
+
+console.log("client activity policy tests passed");

server/src/server.ts

@@ -369,6 +369,9 @@ function trackClientActivity(ws: RuntimeClient, packageID: number) {
     ws.packetCount = Number(ws.packetCount ?? 0) + 1;
 
     if (isPingPacket) {
+        // A valid keepalive ping proves the client is still connected.
+        // Refresh only the idle timestamp; keep ping traffic out of non-ping accounting.
+        ws.lastActivityAt = now;
         return;
     }