src/programs/snap-negative/policy.test.ts

Linked repository file from this build.

import { expect, test } from "bun:test";
import { initialPolicy, policyForMonth, resolveReviewPolicy } from "./policy";
import { calculate, selfEmploymentTotals } from "./calculation";
import { createSeed } from "./seed";
import { policySchema } from "@/features/policy/schema";

test("dated rows select by sample month and retain the saved review table", () => {
  const later = {
    ...initialPolicy,
    id: "future-test",
    effectiveFrom: "2027-01",
    errorThreshold: 59,
    allotments: initialPolicy.allotments.map((amount) => amount + 100),
  };
  expect(policyForMonth("2026-12", [later, initialPolicy])).toBe(initialPolicy);
  expect(policyForMonth("2027-01", [initialPolicy, later])).toBe(later);
  expect(() => policyForMonth("2025-09", [initialPolicy])).toThrow("No published policy");
  const review = createSeed();
  review.policyId = initialPolicy.id;
  review.policy = structuredClone(initialPolicy);
  const before = calculate(
    review.facts.scenarios.compI,
    "2027-01",
    review.calcVersion,
    resolveReviewPolicy(review),
  );
  expect(before.policyId).toBe(initialPolicy.id);
  expect(
    calculate(review.facts.scenarios.compI, "2027-01", review.calcVersion, later).benefitCents,
  ).toBe(before.benefitCents + 10000);
  expect(() => resolveReviewPolicy({ policyId: "missing" })).toThrow("missing");
});

test("policy accepts all twenty rows and money decimals, rejects incomplete tables", () => {
  expect(policySchema.safeParse(initialPolicy).success).toBe(true);
  expect(policySchema.safeParse({ ...initialPolicy, errorThreshold: 58.29 }).success).toBe(true);
  expect(policySchema.safeParse({ ...initialPolicy, grossLimits: [2610] }).success).toBe(false);
  expect(
    policySchema.safeParse({ ...initialPolicy, farmExpenseAllowancePercent: 101 }).success,
  ).toBe(false);
});

test("AF farm gain and loss offset non-farm income before lines 1 and 8", () => {
  const base = createSeed().facts.scenarios.compI;
  const farm = {
    ...base.income[0]!,
    category: "self_employment" as const,
    selfEmploymentKind: "farm" as const,
    amountCents: 10000,
    expensesCents: 30000,
  };
  const nonFarm = {
    ...farm,
    id: "non-farm",
    selfEmploymentKind: "non_farm" as const,
    amountCents: 18000,
    expensesCents: 5000,
  };
  expect(selfEmploymentTotals([farm, nonFarm])).toMatchObject({
    farmGainCents: 0,
    farmLossCents: 20000,
    netBeforeTaxesCents: 13000,
    profitCents: 0,
    lossCents: 7000,
  });
  const loss = calculate({ ...base, income: [farm, nonFarm, base.income[1]!] }, "2026-04");
  expect(loss).toMatchObject({
    earnedCents: 0,
    selfEmploymentLossCents: 7000,
    grossCents: 13000,
    earnedDeductionCents: 0,
  });
  const zero = calculate({ ...base, income: [{ ...farm, expensesCents: 10000 }] }, "2026-04");
  expect(zero).toMatchObject({ earnedCents: 0, selfEmploymentLossCents: 0, grossCents: 0 });
  expect(selfEmploymentTotals([{ ...farm, expensesCents: 5000 }, nonFarm])).toMatchObject({
    farmGainCents: 5000,
    farmLossCents: 0,
    profitCents: 18000,
    lossCents: 0,
  });
  expect(
    selfEmploymentTotals([farm], { ...initialPolicy, farmExpenseAllowancePercent: 50 }),
  ).toMatchObject({ lossCents: 5000 });
});