Wait for round two before adding spare lobbies

tests/unit/autoscaling-snapshot.test.ts

@@ -1,7 +1,9 @@
 import { afterEach, beforeEach, expect, it, vi } from 'vitest';
 import { newFixture, type Fixture } from '../helpers/fixture.js';
 import { prepareNativeHost } from '../helpers/native-host.js';
+import { gameEvent } from '../helpers/telemetry.js';
 import { scalingSettings, type ScalingPolicy } from '../../src/lib/autoscaling.js';
+import type { GameEvent } from '../../src/lib/telemetry.js';
 
 let fixture: Fixture;
 beforeEach(async () => {
@@ -9,6 +11,7 @@ beforeEach(async () => {
     fixture = await newFixture([]);
 });
 afterEach(async () => {
+    vi.useRealTimers();
     await fixture.cleanup();
 });
 const town = 't6_zombie_town_1',
@@ -56,9 +59,90 @@ it('separates variants, deduplicates pending identities, and initializes additiv
     const snapshot = scalingSnapshot(policy);
     expect(snapshot.members).toHaveLength(1);
     expect(snapshot.members[0].state).toBe('creating');
+    expect(snapshot.members[0].round).toBeNull();
     expect(snapshot.reservedNames).toEqual([town]);
 });
 
+async function occupiedLobby() {
+    vi.useFakeTimers({ toFake: ['Date'] });
+    await prepareNativeHost([town]);
+    const { db } = await import('../../src/lib/server/db/index.js');
+    const { scalingSnapshot } = await import('../../src/lib/server/autoscaling/snapshot.js');
+    const now = Date.now();
+    const iso = (offset = 0) => new Date(now + offset).toISOString();
+    db()
+        .prepare(
+            `INSERT INTO servers(name,game,map,map_slug,container_state,container_checked_at,last_seen_at,last_checked_at,last_players,active_since,game_started_at)
+            VALUES(?,'t6','zm_transit','town','running',?,?,?,1,?,?)`
+        )
+        .run(town, iso(), iso(), iso(), iso(-120_000), iso(-60_000));
+    const report = (event: GameEvent['event'], round = 2, offset = -1000, players = 1) => {
+        const payload = {
+            ...gameEvent(event, round, players, town, 'zm_transit'),
+            receivedAt: iso(offset)
+        };
+        db()
+            .prepare(
+                `INSERT OR REPLACE INTO server_telemetry(server,round,players,received_at,payload) VALUES(?,?,?,?,?)`
+            )
+            .run(town, round, players, payload.receivedAt, JSON.stringify(payload));
+    };
+    return { db, now, iso, report, member: () => scalingSnapshot(policy, now).members[0] };
+}
+
+it.each(['round_change', 'heartbeat'] as const)(
+    'exposes the current occupied round from fresh %s reports',
+    async (event) => {
+        const { member, report } = await occupiedLobby();
+        expect(member()).toMatchObject({ state: 'occupied', source: 'rcon', round: null });
+        report(event, 1);
+        expect(member()).toMatchObject({ state: 'occupied', round: 1 });
+        report(event, 2);
+        expect(member()).toMatchObject({ state: 'occupied', round: 2 });
+    }
+);
+
+it('does not borrow stale or future rounds while fresh RCON still proves occupancy', async () => {
+    const { member, report } = await occupiedLobby();
+    for (const offset of [-91_000, 500]) {
+        report('heartbeat', 12, offset);
+        expect(member()).toMatchObject({ state: 'occupied', source: 'rcon', round: null });
+    }
+});
+
+it('clears round evidence at match boundaries and when the lobby empties', async () => {
+    const { db, member, report } = await occupiedLobby();
+    report('heartbeat', 12);
+    expect(member().round).toBe(12);
+    for (const event of ['game_start', 'game_end'] as const) {
+        report(event, 12);
+        expect(member()).toMatchObject({ state: 'occupied', round: null });
+    }
+    report('heartbeat', 12, -1000, 0);
+    // A positive RCON safety veto must not turn an empty report's round into demand.
+    expect(member()).toMatchObject({ state: 'occupied', round: null });
+    db().prepare('UPDATE servers SET last_players=0 WHERE name=?').run(town);
+    expect(member()).toMatchObject({ state: 'empty', round: null });
+});
+
+it('rejects round evidence from before the current occupancy, match, or instance lifecycle', async () => {
+    const { db, iso, member, report } = await occupiedLobby();
+    report('heartbeat', 12);
+    for (const field of ['active_since', 'game_started_at', 'game_ended_at']) {
+        db().prepare(`UPDATE servers SET ${field}=? WHERE name=?`).run(iso(), town);
+        expect(member()).toMatchObject({ state: 'occupied', round: null });
+        db()
+            .prepare(`UPDATE servers SET ${field}=? WHERE name=?`)
+            .run(field === 'game_ended_at' ? null : iso(-120_000), town);
+    }
+    db()
+        .prepare('UPDATE native_instances SET generation_reconciled_at=? WHERE server=?')
+        .run(iso(-500), town);
+    expect(member()).toMatchObject({ state: 'occupied', source: 'rcon', round: null });
+    report('heartbeat', 2, 0);
+    expect(member().round).toBe(2);
+});
+
 it('does not create schema mutations or host work when planning an empty map', async () => {
     const { db } = await import('../../src/lib/server/db/index.js');
     const { scalingSnapshot } = await import('../../src/lib/server/autoscaling/snapshot.js');