mega-plant/lib/rows.test.ts

// Regression tests for buildIncomeRows month aggregation.
//
// Run: node --import tsx --test lib/rows.test.ts
//
// Background: a machine can legitimately have SEVERAL income rows in one month — the
// workbook row plus one row per invoice line booked to it (one machine hired to two sites
// in a month produces two invoice rows). buildIncomeRows used to assign into months[i],
// so the last row read won and the others vanished from the month view while still being
// counted in the YTD total. SS01 September showed R20,700 when it was really R35,305.
import { test } from "node:test";
import assert from "node:assert/strict";
import { buildIncomeRows } from "./rows";

const asset = (id: string, code = "SS01") => ({
  id,
  code,
  name: code,
  category: "Plant",
  type: "",
  gl_account: "",
  supplier: "",
  monthly_excl: 0,
  monthly_incl: 0,
  purchase_value: 0,
  is_provisional: false,
  is_active: true,
}) as any;

const inc = (assetId: string, month: number, income: number, forecast = false) =>
  ({
    id: `${assetId}-${month}-${income}`,
    asset: assetId,
    year: 2026,
    month,
    income,
    fixed_expenses: 0,
    is_forecast: forecast,
  }) as any;

test("two invoice rows in one month are summed, not overwritten", () => {
  // The real SS01 September 2026 case: PHI 167 + PHI 171 booked to the same machine.
  const rows = buildIncomeRows(
    [asset("a1")],
    [inc("a1", 9, 14605), inc("a1", 9, 20700)],
  );
  assert.equal(rows.length, 1);
  const r = rows[0];
  assert.equal(r.months[8], 35305, "September cell must be both invoices");
  assert.equal(r.income, 35305, "YTD total must agree with the month cell");
  // The invariant that was broken: the cells must add up to the headline.
  const sumOfMonths = r.months.reduce((s: number, v: any) => s + (v ?? 0), 0);
  assert.equal(sumOfMonths, r.income, "month cells must sum to YTD income");
});

test("workbook row plus invoice rows in the same month all count", () => {
  const rows = buildIncomeRows([asset("a1")], [inc("a1", 9, 0), inc("a1", 9, 14605), inc("a1", 9, 20700)]);
  assert.equal(rows[0].months[8], 35305);
});

test("months with no actual data stay null", () => {
  // getActualMonthlyIncome() filters forecast rows out before this point, so the guard
  // here is simply "no row for that month -> render a dash".
  const rows = buildIncomeRows([asset("a1")], [inc("a1", 9, 14605)]);
  assert.equal(rows[0].months[8], 14605);
  assert.equal(rows[0].months[9], null, "a month with no actual row must render as null");
  assert.equal(rows[0].months[11], null);
});

test("per-month profit uses the accumulated month, not the last row", () => {
  // Default: profit = income - fixed. Both invoices must be in the month's profit.
  const rows = buildIncomeRows([asset("a1")], [inc("a1", 9, 14605), inc("a1", 9, 20700)]);
  assert.equal(rows[0].profit[8], 35305);
});

test("multi-site machine attributes the VAT across both invoices", () => {
  const line = (id: string, amount: number, vat: number) =>
    ({
      id,
      invoice: "i1",
      line_no: 1,
      machine_code: "SS-01-CASE",
      asset_code: "SS01",
      description: "430 Skidsteer",
      qty: 1,
      unit: "Hr",
      rate: amount,
      rate_type: "Dry Rate",
      amount_excl: amount - vat,
      vat,
      total_incl: amount,
      booked_asset: "a1",
      booked_month: 9,
      booked_year: 2026,
    }) as any;

  const rows = buildIncomeRows(
    [asset("a1")],
    [inc("a1", 9, 14605), inc("a1", 9, 20700)],
    undefined,
    [line("l1", 14605, 1905), line("l2", 20700, 2700)],
  );

  const r = rows[0];
  assert.equal(r.invoiceIncome, 35305, "combined invoice total for the vehicle");
  assert.equal(r.invoiceVat, 4605, "VAT inside that total, across both invoices");
  assert.equal(r.invoiceIncome, r.months[8], "invoice total matches the September cell");
});