ERP/tests/stock.test.ts

import { describe, expect, it } from "vitest";
import { stockOf } from "@/lib/server/stock";
import * as stock from "@/app/api/stock/route";
import * as adjustments from "@/app/api/stock/adjustments/route";
import * as transfers from "@/app/api/stock/transfers/route";
import * as purchases from "@/app/api/purchases/route";
import { json, makeTenant, req, uuid, type Actor, type Tenant } from "./helpers";

async function addStock(t: Tenant, as: Actor, branchId: string, productId: string, quantity: number) {
  const res = await adjustments.POST(
    req("POST", "/x", { as, body: { clientUuid: uuid(), branchId, productId, mode: "DELTA", quantity, note: "opening" } })
  );
  expect(res.status).toBe(201);
}

describe("stock ledger", () => {
  it("adds purchased stock to the receiving branch", async () => {
    const t = await makeTenant();
    const res = await purchases.POST(
      req("POST", "/x", {
        as: t.managerA,
        body: { supplierName: "Kiwanja Water", productId: t.water20, quantity: 40, unitCost: 120 },
      })
    );
    expect(res.status).toBe(201);
    expect(await stockOf(t.businessId, t.branchA, t.water20)).toBe(40);
  });

  it("corrects stock to a physical count, once per submit", async () => {
    const t = await makeTenant();
    await addStock(t, t.owner, t.branchA, t.water20, 50);
    const body = { clientUuid: uuid(), productId: t.water20, mode: "COUNT", quantity: 47, note: "evening count" };
    const first = await json(await adjustments.POST(req("POST", "/x", { as: t.managerA, body })));
    expect(first.body.quantity).toBe(47);
    // A double-submit of the same count changes nothing further.
    const again = await json(await adjustments.POST(req("POST", "/x", { as: t.managerA, body })));
    expect(again.body.quantity).toBe(47);
  });

  it("does not let a manager adjust another branch", async () => {
    const t = await makeTenant();
    const res = await adjustments.POST(
      req("POST", "/x", {
        as: t.managerA,
        body: { clientUuid: uuid(), branchId: t.branchB, productId: t.water20, mode: "DELTA", quantity: 5 },
      })
    );
    expect(res.status).toBe(403);
  });

  it("reports stock per branch with low and out-of-stock flags", async () => {
    const t = await makeTenant();
    await addStock(t, t.owner, t.branchA, t.water20, 8); // threshold defaults to 10
    await addStock(t, t.owner, t.branchA, t.water5, 30);
    const { body } = await json(await stock.GET(req("GET", "/api/stock", { as: t.owner })));
    const find = (b: string, p: string) => body.levels.find((l: any) => l.branchId === b && l.productId === p);
    expect(body.levels).toHaveLength(4); // 2 branches x 2 products, zero rows included
    expect(find(t.branchA, t.water20)).toMatchObject({ quantity: 8, status: "LOW" });
    expect(find(t.branchA, t.water5)).toMatchObject({ quantity: 30, status: "OK" });
    expect(find(t.branchB, t.water20)).toMatchObject({ quantity: 0, status: "OUT" });
  });

  it("shows a cashier only their own branch's stock", async () => {
    const t = await makeTenant();
    const { body } = await json(await stock.GET(req("GET", "/api/stock?branchId=" + t.branchB, { as: t.cashierA })));
    expect(new Set(body.levels.map((l: any) => l.branchId))).toEqual(new Set([t.branchA]));
  });
});

describe("inter-branch transfers", () => {
  it("moves stock out of one branch and into the other", async () => {
    const t = await makeTenant();
    await addStock(t, t.owner, t.branchA, t.water20, 30);
    const res = await transfers.POST(
      req("POST", "/x", {
        as: t.owner,
        body: { clientUuid: uuid(), fromBranchId: t.branchA, toBranchId: t.branchB, productId: t.water20, quantity: 12 },
      })
    );
    expect(res.status).toBe(201);
    expect(await stockOf(t.businessId, t.branchA, t.water20)).toBe(18);
    expect(await stockOf(t.businessId, t.branchB, t.water20)).toBe(12);
  });

  it("applies a double-submitted transfer once", async () => {
    const t = await makeTenant();
    await addStock(t, t.owner, t.branchA, t.water20, 30);
    const body = { clientUuid: uuid(), toBranchId: t.branchB, productId: t.water20, quantity: 10 };
    await transfers.POST(req("POST", "/x", { as: t.managerA, body }));
    const second = await transfers.POST(req("POST", "/x", { as: t.managerA, body }));
    expect(second.status).toBe(200);
    expect(await stockOf(t.businessId, t.branchA, t.water20)).toBe(20);
    expect(await stockOf(t.businessId, t.branchB, t.water20)).toBe(10);
  });

  it("refuses to send more than the branch has", async () => {
    const t = await makeTenant();
    await addStock(t, t.owner, t.branchA, t.water20, 5);
    const res = await transfers.POST(
      req("POST", "/x", {
        as: t.managerA,
        body: { clientUuid: uuid(), toBranchId: t.branchB, productId: t.water20, quantity: 6 },
      })
    );
    expect(res.status).toBe(409);
    expect(await stockOf(t.businessId, t.branchA, t.water20)).toBe(5);
  });

  it("only lets a manager send from their own branch", async () => {
    const t = await makeTenant();
    await addStock(t, t.owner, t.branchB, t.water20, 5);
    const res = await transfers.POST(
      req("POST", "/x", {
        as: t.managerA,
        body: { clientUuid: uuid(), fromBranchId: t.branchB, toBranchId: t.branchA, productId: t.water20, quantity: 1 },
      })
    );
    expect(res.status).toBe(403);
  });

  it("cannot move stock into another tenant's branch", async () => {
    const t = await makeTenant("Alpha");
    const other = await makeTenant("Beta");
    await addStock(t, t.owner, t.branchA, t.water20, 5);
    const res = await transfers.POST(
      req("POST", "/x", {
        as: t.owner,
        body: { clientUuid: uuid(), fromBranchId: t.branchA, toBranchId: other.branchA, productId: t.water20, quantity: 1 },
      })
    );
    expect(res.status).toBe(404);
    expect(await stockOf(t.businessId, t.branchA, t.water20)).toBe(5);
  });
});