Queue consumed on dispatch; engine chain hardened; queued planes unsellable (ISS-088)

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 });
+            }
           }
         }
       }