pelagia-portal/App/tests/integration/po-tcs-discount.test.ts

/**
 * Integration test for PO-level TCS & Discount (issue #133).
 * Verifies totalAmount folds in the charges (subtotal + GST + TCS − Discount),
 * the absolute amounts are persisted, edits update them, and a manager line edit
 * preserves them.
 */
import { vi, describe, it, expect, beforeAll, afterEach } from "vitest";

vi.mock("@/auth", () => ({ auth: vi.fn() }));
vi.mock("next/cache", () => ({ revalidatePath: vi.fn() }));
vi.mock("@/lib/notifier", () => ({ notify: vi.fn() }));

import { auth } from "@/auth";
import { db } from "@/lib/db";
import type { Role } from "@prisma/client";
import { createPo } from "@/app/(portal)/po/new/actions";
import { updatePo } from "@/app/(portal)/po/[id]/edit/actions";
import { managerEditLineItems } from "@/app/(portal)/approvals/[id]/manager-line-edit-actions";
import { makeSession, getSeedUser, getSeedVessel, getSeedAccount, makePoForm, deletePosByTitle } from "./helpers";

const PREFIX = "INTTEST_TCSDISC_";
let techId: string;
let managerId: string;
let vesselId: string;
let accountId: string;

beforeAll(async () => {
  const [tech, manager, vessel, account] = await Promise.all([
    getSeedUser("tech@pelagia.local"),
    getSeedUser("manager@pelagia.local"),
    getSeedVessel("MV Pelagia Star"),
    getSeedAccount("700201"),
  ]);
  techId = tech.id;
  managerId = manager.id;
  vesselId = vessel.id;
  accountId = account.id;
});

afterEach(async () => {
  await deletePosByTitle(PREFIX);
  vi.clearAllMocks();
});

function as(userId: string, role: Role) {
  vi.mocked(auth as unknown as () => Promise<unknown>).mockResolvedValue(makeSession(userId, role));
}

// One line item: 10 × ₹100 @ 18% GST ⇒ taxable 1000, GST 180, incl-GST 1180.
function form(title: string, intent: "draft" | "submit", tcs: number, discount: number) {
  const f = makePoForm({
    title, vesselId, accountId, intent,
    lineItems: [{ description: "Item", quantity: 10, unit: "pc", unitPrice: 100, gstRate: 0.18 }],
  });
  f.set("tcsAmount", String(tcs));
  f.set("discountAmount", String(discount));
  return f;
}

describe("PO TCS & Discount", () => {
  it("folds TCS and Discount into totalAmount and stores the absolute amounts", async () => {
    as(techId, "TECHNICAL");
    const result = await createPo(form(`${PREFIX}Create`, "draft", 118, 100));
    expect(result).not.toHaveProperty("error");

    const po = await db.purchaseOrder.findUniqueOrThrow({ where: { id: (result as { id: string }).id } });
    expect(Number(po.tcsAmount)).toBeCloseTo(118, 2);
    expect(Number(po.discountAmount)).toBeCloseTo(100, 2);
    expect(Number(po.totalAmount)).toBeCloseTo(1180 + 118 - 100, 2); // 1198
  });

  it("defaults to zero charges ⇒ totalAmount is just incl-GST", async () => {
    as(techId, "TECHNICAL");
    const result = await createPo(form(`${PREFIX}Zero`, "draft", 0, 0));
    const po = await db.purchaseOrder.findUniqueOrThrow({ where: { id: (result as { id: string }).id } });
    expect(Number(po.totalAmount)).toBeCloseTo(1180, 2);
    expect(Number(po.tcsAmount)).toBe(0);
    expect(Number(po.discountAmount)).toBe(0);
  });

  it("edit updates the charges and recomputes the total", async () => {
    as(techId, "TECHNICAL");
    const created = await createPo(form(`${PREFIX}Edit`, "draft", 0, 0));
    const poId = (created as { id: string }).id;

    as(techId, "TECHNICAL");
    const edited = await updatePo(poId, form(`${PREFIX}Edit`, "save", 50, 30));
    expect(edited).not.toHaveProperty("error");

    const po = await db.purchaseOrder.findUniqueOrThrow({ where: { id: poId } });
    expect(Number(po.tcsAmount)).toBeCloseTo(50, 2);
    expect(Number(po.discountAmount)).toBeCloseTo(30, 2);
    expect(Number(po.totalAmount)).toBeCloseTo(1180 + 50 - 30, 2); // 1200
  });

  it("a manager line edit preserves the PO's TCS & Discount", async () => {
    as(techId, "TECHNICAL");
    const created = await createPo(form(`${PREFIX}MgrEdit`, "submit", 118, 100)); // ⇒ MGR_REVIEW
    const poId = (created as { id: string }).id;

    as(managerId, "MANAGER");
    const res = await managerEditLineItems({
      poId,
      // Double the quantity: incl-GST becomes 20 × 100 × 1.18 = 2360.
      lineItems: [{ name: "Item", quantity: 20, unit: "pc", unitPrice: 100 }],
    });
    expect(res).not.toHaveProperty("error");

    const po = await db.purchaseOrder.findUniqueOrThrow({ where: { id: poId } });
    expect(Number(po.tcsAmount)).toBeCloseTo(118, 2);
    expect(Number(po.discountAmount)).toBeCloseTo(100, 2);
    expect(Number(po.totalAmount)).toBeCloseTo(2360 + 118 - 100, 2); // 2378
  });
});