fix(e2e): bound post-departure fuel burn in refuel-cost spec (#88)

CHANGELOG.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## v0.46.0 — 2026-09-21 22:32
+- **Queue consumption on dispatch (ISS-088).** `flyPlane` (`lib/game/actions.ts`) now consumes `queue[0]` when the requested destination IS the first queued leg, so a landing never chains a zero-distance self-hop (the "phantom hop" — a→a completing instantly before reaching the real next leg). Flying to a non-first queued leg stays an explicit override and leaves the queue untouched; the persisted queue is written back in the same update
+- **Engine auto-chain hardening.** `deliverPackages` (`lib/sim/engine.ts`) gains two guards: (1) defensive skip — if `queue[0]` equals the arrival airport (only reachable from legacy/corrupt rows now that dispatch consumes), it drops the leg without flying; (2) full-tank backstop — if the next queued leg does not fit even a full tank, the plane grounds as `'available'` with the queue kept intact instead of chaining an unflyable leg (mirrors `flyPlane`'s 409 without throwing mid-tick)
+- **Selling a queued plane is rejected.** `sellPlane` (`lib/game/actions.ts`) returns 409 `the plane has queued legs — cancel queued legs first` for a grounded plane with a non-empty queue, instead of silently discarding the queued legs
+- **Test hook: `/api/test/set-cash`.** New route under `app/api/test/` (sibling of `set-fuel`/`add-cash`) setting account cash to an ABSOLUTE value `{ amount }` — same `FLIGHT_TEST_HOOKS=1` gate, strict JSON validation, post-tick state snapshot. Deliberately NOT in the OpenAPI spec: test hooks are out-of-spec by convention and `lib/openapi.test.ts` pins exactly 13 public paths
+- **Tests.** Unit +5 (373 total): `flyPlane` consumes queue[0] on dispatch / skip-ahead keeps the queue intact; `sellPlane` 409s a grounded plane with queued legs leaving the row untouched; engine full-tank backstop grounds with the queue intact (FGSL ~4267 km from LEMD — beyond ATR range); engine defensive self-leg drop. E2E: `e2e/queue.spec.ts` +3 — three queued legs fly in FIFO order across landings (dispatch response snapshot proves queue[0] consumed), a mid-flight drained tank is topped up before the chained leg at exactly the rep-discounted cost (expectations computed with the same lib helpers as the engine, via `/api/test/set-fuel` drain + new `set-cash` hook), cancelling the only queued leg mid-flight leaves a plain landing with no auto-chain; `e2e/state.spec.ts` +1 — a staged two-leg queue survives `docker compose restart flight` byte-identical; `e2e/two-planes.spec.ts` reworked — the 240 s poll that absorbed the phantom hop is replaced by explicit assertions: the fly response snapshot shows only `[b]` queued, and every state observed while waiting for the chain must never show location a with dest a
+
 ## v0.45.0 — 2026-09-21 21:12
 - **Broken planes cannot fly (ISS-089).** A plane at `health ≤ 0` is now grounded until repaired instead of flying on fumes: `flyPlane` (`lib/game/actions.ts`) rejects it with 409 `the plane is broken (health 0) — repair it first` BEFORE any auto-refuel math, so fuel and cash stay untouched; the engine's auto-chain (`deliverPackages`, `lib/sim/engine.ts`) skips chaining when a landing's wear breaks the plane — it stays grounded at the arrival airport with its queue kept intact for a later dispatch (same shape as an unaffordable top-up)
 - **Repair is gradual.** `repairPlane` no longer jumps health to 100 — it grounds the plane in `'repairing'` with the gate at `clock + REPAIR_DURATION_MS` and leaves health where it was. The engine's `finishRepairs` pass (`lib/sim/engine.ts`) now heals along a linear curve each tick: `health = min(100, max(startHealth, round(f × 100)))` with `f` the fraction of the repair duration elapsed — monotonic (never drops below the start value), and the flip to `'available'` at exactly 100 happens when the gate passes. The left-pane health bar doubles as the repair progress indicator; no UI change

app/api/test/set-cash/route.ts

@@ -0,0 +1,54 @@
+import { getGameDb, persist } from '@/lib/db/client';
+import * as schema from '@/lib/db/schema';
+import { getStateSnapshot } from '@/lib/game/state';
+import { tickNow } from '@/lib/sim/engine';
+
+// TEST-ONLY hook (v0.46.0, ISS-088) — sets the account's cash to an ABSOLUTE value so the e2e suite
+// can stage exact balances (e.g. drain it below a refuel cost to test grounding, then restore it).
+// Disabled unless FLIGHT_TEST_HOOKS=1 (set in docker-compose.yml for the e2e instance only); every
+// other deployment 404s here. Sibling of /api/test/add-cash — same gate, same conventions; add-cash
+// stays for relative grants, this one is exact.
+//
+// POST /api/test/set-cash
+//   body { amount: number } — required; a finite number in [0, ∞) (400 otherwise). Sets
+//   account.cash to exactly that value and returns the full state snapshot after ticking.
+
+export async function POST(req: Request) {
+  if (process.env.FLIGHT_TEST_HOOKS !== '1') {
+    return Response.json({ error: 'test hooks disabled' }, { status: 404 });
+  }
+
+  let body: unknown = {};
+  try {
+    const text = await req.text();
+    body = text ? JSON.parse(text) : {};
+  } catch {
+    return Response.json({ error: 'invalid JSON body' }, { status: 400 });
+  }
+  if (typeof body !== 'object' || body === null || Array.isArray(body)) {
+    return Response.json({ error: 'body must be a JSON object' }, { status: 400 });
+  }
+  const input = body as Record<string, unknown>;
+  for (const key of Object.keys(input)) {
+    if (key !== 'amount') {
+      return Response.json({ error: `unknown field "${key}"` }, { status: 400 });
+    }
+  }
+  const amount = input.amount;
+  if (typeof amount !== 'number' || !Number.isFinite(amount) || amount < 0) {
+    return Response.json({ error: 'amount is required and must be a finite number >= 0' }, { status: 400 });
+  }
+
+  try {
+    const inst = await getGameDb();
+    await tickNow(); // clock is current before the snapshot we return (same as siblings)
+    const account = (await inst.db.select().from(schema.account))[0];
+    if (!account) throw new Error('account row missing');
+    await inst.db.update(schema.account).set({ cash: Math.round(amount * 100) / 100 });
+    await persist(inst);
+    return Response.json(await getStateSnapshot());
+  } catch (err) {
+    console.error('test hook failed', err);
+    return Response.json({ error: 'test hook failed' }, { status: 500 });
+  }
+}

e2e/queue.spec.ts

@@ -1,4 +1,11 @@
 import { test, expect, type Page } from '@playwright/test';
+// Real helpers (v0.46.0) — the refuel expectations must match lib/ exactly; Playwright resolves
+// the repo's tsconfig paths, so importing beats mirroring a fourth copy of the formulas.
+import { loadAirportsGeoJson } from '../lib/airports';
+import { FUEL_DISCOUNT_PER_REP, FUEL_PRICE_PER_L, MAX_FUEL_DISCOUNT, PLANE_TYPES, repRate } from '../lib/game/catalog';
+import { haversineKm, initialBearingDeg } from '../lib/geo';
+import { weatherFor } from '../lib/weather';
+import { fuelAtWeighted, requiredFuelFor, windBurnFactor } from '../lib/sim/movement';
 
 // v0.26.0 — ISS-043 part 2 (UI): the flight queue. A plane's not-yet-started legs show up in a
 // Queue sub-section of its on-board block (cancel per leg; adding happens via fly-to / Relocate
@@ -14,7 +21,9 @@ const QUEUE = 'EHAM'; // Amsterdam — a third airport, distinct from hub and de
 
 interface PlaneState {
   id: string;
+  model: string;
   status: 'available' | 'flying';
+  fuel: number;
   maxFuel: number;
   locationIcao: string;
   destIcao: string | null;
@@ -78,6 +87,17 @@ async function setFuelFull(page: Page, planeId: string): Promise<void> {
   expect((await page.request.post('/api/test/set-fuel', { data: { planeId, fuel: p.maxFuel } })).status()).toBe(200);
 }
 
+// Test hook (FLIGHT_TEST_HOOKS=1): set a plane's tank to an exact level — the engine computes the
+// landed fuel from the row value at arrival, so draining mid-flight stages a known landing state.
+async function setFuel(page: Page, planeId: string, fuel: number): Promise<void> {
+  expect((await page.request.post('/api/test/set-fuel', { data: { planeId, fuel } })).status()).toBe(200);
+}
+
+// Test hook (FLIGHT_TEST_HOOKS=1): set the account's cash to an exact value (v0.46.0).
+async function setCash(page: Page, amount: number): Promise<void> {
+  expect((await page.request.post('/api/test/set-cash', { data: { amount } })).status()).toBe(200);
+}
+
 // Self-heal: let any in-flight leg finish, reposition plane-starter home via the API, and abandon
 // leftover cargo so every test starts from the canonical state even after an interrupted run.
 async function flyHomeViaApi(page: Page): Promise<void> {
@@ -450,3 +470,139 @@ test('landing auto-starts the next queued leg (ISS-043 chain end-to-end)', async
     return !!p && p.status === 'available' && p.locationIcao === HUB;
   }, { timeout: 120_000, message: `waiting for the chained leg to land back at ${HUB}` }).toBe(true);
 });
+
+// --- v0.46.0 (ISS-088): queue consumption on dispatch + refuel between legs ---
+
+test('three queued legs fly in FIFO order across landings (v0.46.0)', async ({ page }) => {
+  test.setTimeout(300_000); // self-heal + three chained legs at scale 1000
+  await flyHomeViaApi(page);
+
+  await setFuelFull(page, 'plane-starter');
+
+  // Pre-build a 3-leg route while grounded: LEMD → EHAM → back to the hub.
+  for (const icao of [DEST, QUEUE, HUB]) {
+    expect((await page.request.post('/api/planes/plane-starter/queue', { data: { destIcao: icao } })).status()).toBe(200);
+  }
+
+  // Start leg 1 — the response snapshot must show queue[0] CONSUMED (v0.46.0): no phantom self-hop on landing.
+  const flyRes = await page.request.post('/api/planes/plane-starter/fly', { data: { destIcao: DEST } });
+  expect(flyRes.status()).toBe(200);
+  const p0 = ((await flyRes.json()) as StateBody).planes.find((x) => x.id === 'plane-starter')!;
+  expect(p0.status).toBe('flying');
+  expect(p0.destIcao).toBe(DEST);
+  expect(p0.queue, 'queue[0] consumed on dispatch — the rest stays in order').toEqual([QUEUE, HUB]);
+
+  // Landing at DEST auto-chains EHAM (leg 2)…
+  await setScale(page, SCALE);
+  await expect.poll(async () => {
+    const x = (await getState(page)).planes.find((y) => y.id === 'plane-starter');
+    return !!x && x.status === 'flying' && x.destIcao === QUEUE;
+  }, { timeout: 120_000, message: `waiting for the auto-chained leg ${DEST} → ${QUEUE}` }).toBe(true);
+
+  // …and landing at EHAM chains the return to HUB (leg 3).
+  await expect.poll(async () => {
+    const x = (await getState(page)).planes.find((y) => y.id === 'plane-starter');
+    return !!x && x.status === 'flying' && x.destIcao === HUB;
+  }, { timeout: 120_000, message: `waiting for the auto-chained leg ${QUEUE} → ${HUB}` }).toBe(true);
+
+  await expect.poll(async () => {
+    const x = (await getState(page)).planes.find((y) => y.id === 'plane-starter');
+    return !!x && x.status === 'available' && x.locationIcao === HUB;
+  }, { timeout: 120_000, message: `waiting for the chained leg to land back at ${HUB}` }).toBe(true);
+
+  expect((await getState(page)).planes.find((x) => x.id === 'plane-starter')!.queue).toEqual([]); // all three consumed in order
+});
+
+test('a drained tank is topped up before a chained leg at exactly the rep-discounted cost (v0.46.0)', async ({ page }) => {
+  test.setTimeout(300_000); // self-heal + two legs at scale 1000
+  await flyHomeViaApi(page);
+
+  const s0 = await getState(page);
+  const type = PLANE_TYPES.atr72; // the starter model (STARTER_MODEL)
+  expect(s0.planes.find((x) => x.id === 'plane-starter')!.model).toBe('atr72'); // sanity: the catalog mirror is valid
+
+  // Full tank → leg 1 dispatch is a free no-op top-up, so only the CHAIN refuel moves cash. Stage an
+  // exact balance (v0.46.0 hook) so the expectation holds regardless of what earlier tests earned.
+  await setFuelFull(page, 'plane-starter');
+  const STAGED_CASH = 20_000;
+  await setCash(page, STAGED_CASH);
+  const q = await page.request.post('/api/planes/plane-starter/queue', { data: { destIcao: QUEUE } });
+  expect(q.status()).toBe(200);
+
+  const flyRes = await page.request.post('/api/planes/plane-starter/fly', { data: { destIcao: DEST } });
+  expect(flyRes.status()).toBe(200);
+  const cashBeforeChain = ((await flyRes.json()) as StateBody).account.cash;
+  expect(cashBeforeChain).toBe(STAGED_CASH); // dispatch was a free no-op — the staged balance is intact
+
+  // Drain the tank mid-flight — the engine computes the landed fuel from this row value at arrival.
+  await setFuel(page, 'plane-starter', 0);
+
+  // Expected chain refuel from the SAME helpers the engine uses (wind-adjusted, v0.36.0): leg 1 lands
+  // empty; leg DEST→QUEUE needs a top-up to min(maxFuel, max(landed, 1.5 × required)).
+  const fc = await loadAirportsGeoJson();
+  const hubP = fc.features.find((f) => f.properties.icao === HUB)!.properties;
+  const destP = fc.features.find((f) => f.properties.icao === DEST)!.properties;
+  const queueP = fc.features.find((f) => f.properties.icao === QUEUE)!.properties;
+
+  const km1 = haversineKm(hubP.lat, hubP.lon, destP.lat, destP.lon);
+  const wHub = weatherFor(HUB);
+  const burn1 = type.burnPerKm * windBurnFactor(wHub.windKt, wHub.windDirDeg, initialBearingDeg(hubP.lat, hubP.lon, destP.lat, destP.lon));
+  const landedFuel = fuelAtWeighted(0, burn1, type.emptyWeightKg, type.maxFuel, km1, 1); // drained → lands empty
+  expect(landedFuel).toBeCloseTo(0, 6);
+
+  const km2 = haversineKm(destP.lat, destP.lon, queueP.lat, queueP.lon);
+  const wDest = weatherFor(DEST); // the chained leg departs from the arrival airport
+  const burn2 = type.burnPerKm * windBurnFactor(wDest.windKt, wDest.windDirDeg, initialBearingDeg(destP.lat, destP.lon, queueP.lat, queueP.lon));
+  const required2 = requiredFuelFor(burn2, type.emptyWeightKg, type.maxFuel, km2);
+  expect(required2).toBeGreaterThan(landedFuel); // the top-up path genuinely runs
+
+  const target = Math.min(type.maxFuel, Math.max(landedFuel, required2 * 1.5));
+  const liters = Math.max(0, target - landedFuel);
+  const rate = repRate(s0.account.reputation, FUEL_DISCOUNT_PER_REP, MAX_FUEL_DISCOUNT);
+  const expectedCost = Math.round(liters * FUEL_PRICE_PER_L * (1 - rate) * 100) / 100;
+
+  // Landing at DEST auto-chains QUEUE with the top-up…
+  await setScale(page, SCALE);
+  await expect.poll(async () => {
+    const x = (await getState(page)).planes.find((y) => y.id === 'plane-starter');
+    return !!x && x.status === 'flying' && x.destIcao === QUEUE;
+  }, { timeout: 120_000, message: `waiting for the auto-chained leg ${DEST} → ${QUEUE}` }).toBe(true);
+
+  const s = await getState(page);
+  // Exact fuel equality is impossible — this snapshot lands after leg 2's departure burn; the exact top-up level × rep-discounted price is pinned by the cash assertion below.
+  const fuel = s.planes.find((x) => x.id === 'plane-starter')!.fuel;
+  expect(fuel).toBeLessThanOrEqual(target); // can only have burned since departure…
+  expect(fuel).toBeGreaterThan(1.4 * required2); // …and a wrong top-up level (≤ required2, or none at all) lands below this bound
+  expect(s.account.cash).toBeCloseTo(cashBeforeChain - expectedCost, 6); // at exactly the rep-discounted cost
+
+  // Let leg 2 finish so the next test starts from a known airport.
+  await expect.poll(async () => {
+    const x = (await getState(page)).planes.find((y) => y.id === 'plane-starter');
+    return !!x && x.status === 'available' && x.locationIcao === QUEUE;
+  }, { timeout: 120_000, message: `waiting for the chained leg to land at ${QUEUE}` }).toBe(true);
+});
+
+test('cancelling the only queued leg mid-flight leaves a plain landing (v0.46.0)', async ({ page }) => {
+  test.setTimeout(300_000); // self-heal + one leg at scale 1000
+  await flyHomeViaApi(page);
+
+  await setFuelFull(page, 'plane-starter');
+  const q = await page.request.post('/api/planes/plane-starter/queue', { data: { destIcao: QUEUE } });
+  expect(q.status()).toBe(200);
+  const flyRes = await page.request.post('/api/planes/plane-starter/fly', { data: { destIcao: DEST } });
+  expect(flyRes.status()).toBe(200);
+
+  // Cancel the queued leg while airborne — landing at DEST must be a plain grounding, no auto-chain.
+  const cancel = await page.request.post('/api/planes/plane-starter/queue/cancel', { data: { index: 0 } });
+  expect(cancel.status()).toBe(200);
+
+  await setScale(page, SCALE);
+  await expect.poll(async () => {
+    const x = (await getState(page)).planes.find((y) => y.id === 'plane-starter');
+    return !!x && x.status === 'available' && x.locationIcao === DEST;
+  }, { timeout: 120_000, message: `waiting for plane-starter to land at ${DEST}` }).toBe(true);
+
+  const p = (await getState(page)).planes.find((x) => x.id === 'plane-starter')!;
+  expect(p.destIcao).toBeNull(); // no chained leg started…
+  expect(p.queue).toEqual([]); // …and the queue is empty
+});

e2e/state.spec.ts

@@ -82,3 +82,49 @@ test('state survives a container restart (sim clock + account persisted)', async
   expect(a.planes.map((p) => p.id).sort()).toEqual(before.planes.map((p) => p.id).sort());
   expect(a.packages.map((p) => p.id).sort()).toEqual(before.packages.map((p) => p.id).sort());
 });
+
+test('queued legs survive a container restart (v0.46.0)', async ({ page }) => {
+  test.setTimeout(180_000);
+
+  // Self-heal: the suite runs serially and every spec leaves plane-starter grounded, but an
+  // interrupted run may not — wait it out before staging a queue (queueLeg works while flying too).
+  await expect
+    .poll(async () => {
+      const res = await page.request.get('/api/state');
+      if (res.status() !== 200) return 'down';
+      const body = (await res.json()) as StateBody;
+      return String(body.planes.find((p) => p.id === 'plane-starter')?.status ?? 'missing');
+    }, { timeout: 120_000, message: 'waiting for plane-starter to be grounded' })
+    .toBe('available');
+
+  // Stage a two-leg queue on the starter…
+  const q1 = await page.request.post('/api/planes/plane-starter/queue', { data: { destIcao: 'LEMD' } });
+  expect(q1.status()).toBe(200);
+  const q2 = await page.request.post('/api/planes/plane-starter/queue', { data: { destIcao: 'EHAM' } });
+  expect(q2.status()).toBe(200);
+
+  execSync(`docker compose ${composeArgs} restart flight`, { cwd: repoRoot, stdio: 'pipe' });
+
+  // Wait for the app to come back, capturing the post-restart snapshot.
+  let after: StateBody | undefined;
+  await expect
+    .poll(async () => {
+      try {
+        const res = await page.request.get('/api/state');
+        if (res.status() === 200) after = (await res.json()) as StateBody;
+        return !!after;
+      } catch {
+        return false; // connection refused / 502 while the container starts
+      }
+    }, { timeout: 120_000, message: 'waiting for /api/state after docker compose restart' })
+    .toBe(true);
+
+  const p = after!.planes.find((x) => x.id === 'plane-starter')!;
+  expect(p.queue).toEqual(['LEMD', 'EHAM']); // the queue persisted byte-identical, in order…
+
+  // Cleanup: cancel both legs so the starter is left with an empty queue.
+  for (let i = 0; i < 2; i++) {
+    const c = await page.request.post('/api/planes/plane-starter/queue/cancel', { data: { index: 0 } });
+    expect(c.status()).toBe(200);
+  }
+});

e2e/two-planes.spec.ts

@@ -495,20 +495,30 @@ test('per-plane queues are independent; landing auto-chains the next queued leg'
   await expect(page.getByTestId(`queue-leg-${secondId}-0`), 'the cancelled leg is gone').toHaveCount(0, { timeout: 15_000 });
   await expect(starterLeg0, 'the starter queue is untouched by the other plane cancel').toContainText(a.icao);
 
-  // Fly the STARTER to its first queued destination…
+  // Fly the STARTER to its first queued destination — v0.46.0 consumes queue[0] on dispatch, so the
+  // response snapshot must already show only [b] left (previously the leg stayed queued and the
+  // landing chained a zero-distance self-hop a→a before reaching b).
   const flyRes = await page.request.post(`/api/planes/${STARTER}/fly`, { data: { destIcao: a.icao } });
   expect(flyRes.status()).toBe(200);
+  const flyBody = (await flyRes.json()) as StateBody;
+  expect(flyBody.planes.find((x) => x.id === STARTER)!.queue, 'queue[0] consumed on dispatch').toEqual([b.icao]);
 
   // …fast-forward; on landing at a the server AUTO-CHAINS queue[0] (b) in the same tick — but with
   // the second plane still grounded, ISS-057 slows the sim to 1× on that landing. Wait for the chain…
   await setScale(page, SCALE);
+  const seen: Array<{ locationIcao: string; destIcao: string | null }> = [];
   await expect
     .poll(async () => {
       const p = (await getState(page)).planes.find((x) => x.id === STARTER);
+      if (p && p.status === 'flying') seen.push({ locationIcao: p.locationIcao, destIcao: p.destIcao });
       return !!p && p.status === 'flying' && p.destIcao === b.icao;
-    }, { timeout: 240_000, message: `waiting for the auto-chained leg ${a} → ${b} to start` })
+    }, { timeout: 120_000, message: `waiting for the auto-chained leg ${a} → ${b} to start` })
     .toBe(true);
 
+  // …and NO snapshot may show the phantom self-hop (location a with dest a) — every observed state
+  // is either the outbound leg (HUB→a) or the chained leg (a→b).
+  expect(seen.filter((s) => s.locationIcao === a.icao && s.destIcao === a.icao), 'phantom self-hop a → a').toEqual([]);
+
   // …then restore speed so the chained leg fast-forwards too.
   await setScale(page, SCALE);
   await expect

lib/game/actions.test.ts

@@ -331,6 +331,34 @@ describe('flyPlane', () => {
 
     await expectActionError(flyPlane(inst, 'plane-starter', 'LPPD'), 409, /insufficient fuel/i);
   });
+
+  // --- Queue consumption on dispatch (v0.46.0, ISS-088) ---
+
+  it('consumes queue[0] when flying to the first queued leg — no phantom self-hop on landing', async () => {
+    const inst = await freshDb('fly-consume.db');
+    await queueLeg(inst, 'plane-starter', 'LEMD');
+    await queueLeg(inst, 'plane-starter', 'EHAM');
+
+    await flyPlane(inst, 'plane-starter', 'LEMD'); // the first queued leg
+
+    const plane = (await inst.db.select().from(schema.planes))[0];
+    expect(plane.status).toBe('flying');
+    expect(plane.destIcao).toBe('LEMD');
+    expect(JSON.parse(plane.queue)).toEqual(['EHAM']); // queue[0] consumed, the rest kept in order
+  });
+
+  it('keeps the queue intact when skipping ahead to a non-first queued leg (explicit override)', async () => {
+    const inst = await freshDb('fly-skipahead.db');
+    await queueLeg(inst, 'plane-starter', 'LEMD');
+    await queueLeg(inst, 'plane-starter', 'EHAM');
+
+    await flyPlane(inst, 'plane-starter', 'EHAM'); // not the first queued leg — an override
+
+    const plane = (await inst.db.select().from(schema.planes))[0];
+    expect(plane.status).toBe('flying');
+    expect(plane.destIcao).toBe('EHAM');
+    expect(JSON.parse(plane.queue)).toEqual(['LEMD', 'EHAM']); // untouched — FIFO order preserved
+  });
 });
 
 describe('queueLeg (v0.25.0, ISS-043)', () => {
@@ -671,6 +699,19 @@ describe('sellPlane', () => {
     expect(ids).toContain('plane-extra'); // row untouched — the cargo stays bound to a real plane
   });
 
+  it('rejects selling a grounded plane with queued legs with 409 (v0.46.0, ISS-088)', async () => {
+    const inst = await freshDb('sell-queue.db');
+    await inst.db.insert(schema.planes).values({
+      id: 'plane-extra', model: 'atr72', status: 'available', fuel: 100, maxFuel: PLANE_TYPES.atr72.maxFuel,
+      locationIcao: HUB_ICAO, destIcao: null, lat: 50, lon: 8, departureSimTime: null,
+    });
+    await queueLeg(inst, 'plane-extra', 'LEMD');
+
+    await expectActionError(sellPlane(inst, 'plane-extra'), 409, /cancel queued legs first/);
+    const plane = (await inst.db.select().from(schema.planes).where(eq(schema.planes.id, 'plane-extra')))[0];
+    expect(JSON.parse(plane.queue)).toEqual(['LEMD']); // row untouched — the queue stays with a real plane
+  });
+
   it('rejects selling the last remaining plane with 409', async () => {
     const inst = await freshDb('sell-last.db'); // only the starter exists
     await expectActionError(sellPlane(inst, 'plane-starter'), 409, /last remaining/);

lib/game/actions.ts

@@ -153,6 +153,12 @@ export async function flyPlane(inst: GameDb, planeId: string, destIcao: string):
   const sim = (await inst.db.select().from(schema.simState))[0];
   if (!sim) throw new Error('sim_state row missing');
 
+  // v0.46.0 (ISS-088): flying to the FIRST queued leg consumes it — otherwise the engine would
+  // chain a zero-distance self-hop on landing (queue[0] === the airport just reached). Skip-ahead
+  // to a non-first queued dest is an explicit override: the queue stays intact, FIFO preserved.
+  const queue = parseIcaoQueue(plane.queue);
+  if (queue.length > 0 && queue[0] === destIcao) queue.shift();
+
   await inst.db.update(schema.planes)
     .set({
       status: 'flying',
@@ -161,6 +167,7 @@ export async function flyPlane(inst: GameDb, planeId: string, destIcao: string):
       lat: origin.lat,
       lon: origin.lon,
       fuel: target, // ISS-082: the post-top-up level (unchanged when no top-up was needed)
+      queue: JSON.stringify(queue),
     })
     .where(eq(schema.planes.id, planeId));
   if (cost > 0) {
@@ -340,6 +347,11 @@ export async function sellPlane(inst: GameDb, planeId: string): Promise<{ payout
     throw new GameActionError(409, `cannot sell a plane carrying cargo`);
   }
 
+  // v0.46.0 (ISS-088): selling a plane with queued legs would silently drop them — force an explicit cancel first.
+  if (parseIcaoQueue(plane.queue).length > 0) {
+    throw new GameActionError(409, 'the plane has queued legs — cancel queued legs first');
+  }
+
   const all = await inst.db.select().from(schema.planes);
   if (all.length <= 1) throw new GameActionError(409, 'cannot sell the last remaining plane');
 

lib/sim/engine.test.ts

@@ -378,6 +378,52 @@ describe('deliverPackages (v0.12.0 arrival delivery)', () => {
     expect(plane.status).toBe('available'); // unchanged landing behavior…
     expect(JSON.parse(plane.queue)).toEqual([]); // …and the queue stays empty
   });
+
+  it('grounds with the queue intact when the next leg does not fit even a full tank (v0.46.0 backstop)', async () => {
+    const { inst, to, km, type } = await setupFlight('chain-nofit.db'); // full tank EDDF→LEMD
+    const fc = await loadAirportsGeoJson();
+    const farP = fc.features.find((f) => f.properties.icao === 'FGSL')!.properties; // ~4267 km from LEMD — beyond ATR range
+
+    // Precondition sanity: the LEMD→FGSL hop genuinely does not fit a full tank (wind-adjusted,
+    // exactly as deliverPackages computes it) — so no top-up could ever make it flyable.
+    const wTo = weatherFor(TO);
+    const fNext = windBurnFactor(wTo.windKt, wTo.windDirDeg, initialBearingDeg(to.lat, to.lon, farP.lat, farP.lon));
+    const nextRequiredL = requiredFuelFor(
+      type.burnPerKm * fNext,
+      type.emptyWeightKg,
+      type.maxFuel,
+      haversineKm(to.lat, to.lon, farP.lat, farP.lon),
+    );
+    expect(nextRequiredL).toBeGreaterThan(type.maxFuel);
+
+    await inst.db.update(schema.planes)
+      .set({ queue: JSON.stringify(['FGSL']) })
+      .where(eq(schema.planes.id, 'plane-starter'));
+
+    const clock = T0 + travelMs(km, type.speedKmh); // exactly at arrival
+    expect(await deliverPackages(inst, clock)).toBe(1);
+
+    const plane = (await inst.db.select().from(schema.planes))[0];
+    expect(plane.status).toBe('available'); // grounded — the unflyable leg was NOT chained…
+    expect(plane.destIcao).toBeNull();
+    expect(JSON.parse(plane.queue)).toEqual(['FGSL']); // …queue kept intact for a later dispatch
+  });
+
+  it('drops a queued leg to the arrival airport without flying — defensive guard for legacy rows (v0.46.0)', async () => {
+    const { inst, km, type } = await setupFlight('chain-selfleg.db'); // full tank EDDF→LEMD
+    // Legacy state: queue[0] is the airport we are about to land at — pre-v0.46.0 this chained a
+    // zero-distance self-hop (the phantom hop). The guard drops it and grounds instead.
+    await inst.db.update(schema.planes)
+      .set({ queue: JSON.stringify(['LEMD', 'EHAM']) })
+      .where(eq(schema.planes.id, 'plane-starter'));
+
+    expect(await deliverPackages(inst, T0 + travelMs(km, type.speedKmh))).toBe(1);
+
+    const plane = (await inst.db.select().from(schema.planes))[0];
+    expect(plane.status).toBe('available'); // grounded — the self-leg was dropped, not flown…
+    expect(plane.destIcao).toBeNull();
+    expect(JSON.parse(plane.queue)).toEqual(['EHAM']); // …the rest of the queue kept for a later dispatch
+  });
 });
 
 describe('wear on landed legs (v0.39.0, ISS-069)', () => {

lib/sim/engine.ts

@@ -246,32 +246,43 @@ export async function deliverPackages(inst: GameDb, clockMs: number): Promise<nu
     let topUpFuel: number | null = null; // post-top-up fuel for the chained departure, when a top-up happened
     if (queue.length > 0 && newHealth > 0) {
       const nextDest = queue[0];
-      const next = byIcao.get(nextDest); // unknown ICAO in the queue → cannot chain
-      if (next) {
-        // Wind-adjusted requirement for the NEXT leg — it departs from `to` (v0.36.0).
-        const wNext = weatherFor(to.icao);
-        const nextRequiredL = requiredFuelFor(
-          type.burnPerKm * windBurnFactor(wNext.windKt, wNext.windDirDeg, initialBearingDeg(to.lat, to.lon, next.lat, next.lon)),
-          type.emptyWeightKg,
-          type.maxFuel,
-          haversineKm(to.lat, to.lon, next.lat, next.lon),
-        );
-        if (nextRequiredL <= landedFuel) {
-          queue.shift();
-          chainedTo = nextDest;
-        } else {
-          // ISS-082: auto top-up — same target/price terms as flyPlane's dispatch refuel.
-          const target = Math.min(type.maxFuel, Math.max(landedFuel, nextRequiredL * 1.5));
-          const liters = Math.max(0, target - landedFuel);
-          // Fresh account read (same pattern as the delivery awards above) so a top-up in this tick sees current cash.
-          const fresh = (await inst.db.select().from(schema.account))[0];
-          if (!fresh) throw new Error('account row missing');
-          const cost = Math.round(liters * FUEL_PRICE_PER_L * (1 - repRate(fresh.reputation, FUEL_DISCOUNT_PER_REP, MAX_FUEL_DISCOUNT)) * 100) / 100;
-          if (cost === 0 || fresh.cash >= cost) {
+      // ponytail: defensive guard for legacy rows — a queued leg to the airport we just landed at is a
+      // zero-distance no-op hop; drop it and ground instead of flying. Normal play can't produce this
+      // since v0.46.0 (flyPlane consumes queue[0] on dispatch, every chain shifts its own leg).
+      if (nextDest === to.icao) {
+        queue.shift();
+      } else {
+        const next = byIcao.get(nextDest); // unknown ICAO in the queue → cannot chain
+        if (next) {
+          // Wind-adjusted requirement for the NEXT leg — it departs from `to` (v0.36.0).
+          const wNext = weatherFor(to.icao);
+          const nextRequiredL = requiredFuelFor(
+            type.burnPerKm * windBurnFactor(wNext.windKt, wNext.windDirDeg, initialBearingDeg(to.lat, to.lon, next.lat, next.lon)),
+            type.emptyWeightKg,
+            type.maxFuel,
+            haversineKm(to.lat, to.lon, next.lat, next.lon),
+          );
+          // v0.46.0 backstop: a leg that doesn't fit even a full tank is unflyable — ground with the queue
+          // intact, mirroring flyPlane's 409 without throwing in the engine.
+          if (nextRequiredL > type.maxFuel) {
+            // no chain — the grounded update below keeps the queue for a later dispatch
+          } else if (nextRequiredL <= landedFuel) {
             queue.shift();
             chainedTo = nextDest;
-            topUpFuel = target;
-            if (cost > 0) await inst.db.update(schema.account).set({ cash: Math.round((fresh.cash - cost) * 100) / 100 });
+          } else {
+            // ISS-082: auto top-up — same target/price terms as flyPlane's dispatch refuel.
+            const target = Math.min(type.maxFuel, Math.max(landedFuel, nextRequiredL * 1.5));
+            const liters = Math.max(0, target - landedFuel);
+            // Fresh account read (same pattern as the delivery awards above) so a top-up in this tick sees current cash.
+            const fresh = (await inst.db.select().from(schema.account))[0];
+            if (!fresh) throw new Error('account row missing');
+            const cost = Math.round(liters * FUEL_PRICE_PER_L * (1 - repRate(fresh.reputation, FUEL_DISCOUNT_PER_REP, MAX_FUEL_DISCOUNT)) * 100) / 100;
+            if (cost === 0 || fresh.cash >= cost) {
+              queue.shift();
+              chainedTo = nextDest;
+              topUpFuel = target;
+              if (cost > 0) await inst.db.update(schema.account).set({ cash: Math.round((fresh.cash - cost) * 100) / 100 });
+            }
           }
         }
       }

package.json

@@ -1,6 +1,6 @@
 {
   "name": "flight-ops",
-  "version": "0.45.0",
+  "version": "0.46.0",
   "private": true,
   "scripts": {
     "dev": "next dev -p 3000",