fix issue and add consolidation

apps/edr-freight-api/src/modules/train-scheduling/booking-batch.smart-need.spec.ts

@@ -0,0 +1,104 @@
+import { Booking } from '../bookings/entities/booking.entity';
+import { BookingBatchService } from './booking-batch.service';
+import { WagonStockLedger } from './wagon-stock-ledger.util';
+
+/**
+ * smartBulkNeed math in isolation: the private helpers it touches
+ * (allowedDimsWithTypes) read only their arguments, so a bare prototype
+ * instance is enough — no Nest wiring.
+ */
+describe('BookingBatchService.smartBulkNeed', () => {
+  const service = Object.create(BookingBatchService.prototype) as BookingBatchService;
+  const call = (
+    booking: Booking,
+    stock: WagonStockLedger,
+    rank: Map<string, number>,
+  ) =>
+    (
+      service as unknown as {
+        smartBulkNeed: (
+          b: Booking,
+          d: unknown,
+          s: WagonStockLedger,
+          l: { fromEdge: number; toEdge: number },
+          r: Map<string, number>,
+        ) => { need: { wagons: number }; perType: Array<{ wagonTypeId: string; wagons: number }> } | null;
+      }
+    ).smartBulkNeed(booking, wagonDims, stock, { fromEdge: 0, toEdge: 1 }, rank);
+
+  const nw5 = { id: 'wt-nw5', capacityTons: 70 };
+  const pw2 = { id: 'wt-pw2', capacityTons: 70 };
+  const perishable = {
+    id: 'cargo-perishable',
+    wagonTypes: [nw5, pw2],
+    tonsPerWagonMap: { [nw5.id]: 30, [pw2.id]: 20 },
+  };
+  const wagonDims = {
+    container: { lengthMeters: 14, tareWeightTons: 24, capacityTons: 70 },
+    bulk: { lengthMeters: 14, tareWeightTons: 24, capacityTons: 70 },
+    byWagonTypeId: new Map([
+      [nw5.id, { lengthMeters: 14, tareWeightTons: 24, capacityTons: 70 }],
+      [pw2.id, { lengthMeters: 14, tareWeightTons: 24, capacityTons: 70 }],
+    ]),
+  };
+  const booking = (tons: number): Booking =>
+    ({
+      id: 'b1',
+      reference: 'b1',
+      freightType: 'BULK',
+      cargoTotalWeightVgm: tons,
+      cargoTypeId: perishable.id,
+      cargoType: perishable,
+      bookingContainers: [],
+    }) as unknown as Booking;
+  // Containers compete for NW5 → NW5 rank 2, PW2 rank 1.
+  const contested = new Map([
+    [nw5.id, 2],
+    [pw2.id, 1],
+  ]);
+
+  it('seats 695T as 10 PW2 (20T) + 17 NW5 (30T) = 27 wagons, PW2 first', () => {
+    const stock = new WagonStockLedger(
+      new Map([
+        [nw5.id, 18],
+        [pw2.id, 10],
+      ]),
+      1,
+    );
+    const smart = call(booking(695), stock, contested);
+    expect(smart).not.toBeNull();
+    expect(smart!.need.wagons).toBe(27);
+    expect(smart!.perType).toEqual([
+      { wagonTypeId: pw2.id, wagons: 10 },
+      { wagonTypeId: nw5.id, wagons: 17 },
+    ]);
+  });
+
+  it('returns null when the free stock cannot seat the whole booking', () => {
+    const stock = new WagonStockLedger(
+      new Map([
+        [nw5.id, 5],
+        [pw2.id, 10],
+      ]),
+      1,
+    );
+    // 10×20 + 5×30 = 350T < 695T.
+    expect(call(booking(695), stock, contested)).toBeNull();
+  });
+
+  it('uncontested types fall back to biggest per-cargo take (fewest wagons)', () => {
+    const stock = new WagonStockLedger(
+      new Map([
+        [nw5.id, 10],
+        [pw2.id, 10],
+      ]),
+      1,
+    );
+    const even = new Map([
+      [nw5.id, 1],
+      [pw2.id, 1],
+    ]);
+    const smart = call(booking(60), stock, even);
+    expect(smart!.perType).toEqual([{ wagonTypeId: nw5.id, wagons: 2 }]);
+  });
+});