/** * Hand-computed expected values, barème IR 2026 (2025 income). * Every case documents its manual computation so a reviewer can re-derive it. * Bracket cumulative anchors (per part): * at 29 579 € → 1 977.69 € ; at 84 577 € → 18 477.09 € ; at 181 917 € → 58 386.49 €. */ import { describe, expect, it } from "vitest"; import { computeIr, fiscalParts } from "../ir"; import { computePortage } from "../portage"; import { simulate } from "../scenarios"; const noOpt = { fraisReels: undefined, versementsPER: undefined, dons: undefined }; describe("fiscalParts", () => { it("counts garde alternée as quarter parts after resident children", () => { expect(fiscalParts({ maritalStatus: "celibataire", children: 0, childrenGardeAlternee: 0 })).toBe(1); expect(fiscalParts({ maritalStatus: "marie_pacse", children: 2, childrenGardeAlternee: 0 })).toBe(3); expect(fiscalParts({ maritalStatus: "celibataire", children: 0, childrenGardeAlternee: 1 })).toBe(1.25); expect(fiscalParts({ maritalStatus: "marie_pacse", children: 1, childrenGardeAlternee: 1 })).toBe(2.75); // 3rd child counts full part — here in shared custody → half part. expect(fiscalParts({ maritalStatus: "marie_pacse", children: 2, childrenGardeAlternee: 1 })).toBe(3.5); }); }); describe("computeIr — 10 hand-computed cases", () => { // Case 1 — single, no children, 30 000 € taxable (input is pre-deduction: // 33 333 € salary − 10% = 30 000). q=30 000 → 1 977.69 + 0.30×421 = 2 103.99. // Above décote threshold (1 982) → tax 2 104. it("1. célibataire sans enfant", () => { const r = computeIr({ household: { maritalStatus: "celibataire", children: 0, childrenGardeAlternee: 0 }, salaryTaxable: 33_333.33, ...noOpt, }); expect(r.taxableIncome).toBe(30_000); expect(r.tax).toBe(2_104); expect(r.marginalRate).toBe(0.3); }); // Case 2 — couple, 2 children, 60 000 € taxable. P=3, q=20 000 → // 0.11×8 400=924 ×3 = 2 772. QF advantage 4 208−2 772=1 436 < cap 3 614. // Décote couple: 1 484 − 0.4525×2 772 = 229.67 → tax 2 772 − 229.67 = 2 542. it("2. couple 2 enfants avec décote", () => { const r = computeIr({ household: { maritalStatus: "marie_pacse", children: 2, childrenGardeAlternee: 0 }, salaryTaxable: 66_666.67, ...noOpt, }); expect(r.taxableIncome).toBe(60_000); expect(r.tax).toBe(2_542); }); // Case 3 — QF cap binding: couple, 2 children, salary 164 556 €; the 10% // deduction (16 455 €) is CAPPED at 14 555 € (max officiel 2025) → taxable // 150 001. Advantage > cap 3 614 → tax = base − 3 614 ≈ 27 594. it("3. plafonnement du quotient familial + plafond abattement 10%", () => { const r = computeIr({ household: { maritalStatus: "marie_pacse", children: 2, childrenGardeAlternee: 0 }, salaryTaxable: 164_556, ...noOpt, }); expect(r.taxableIncome).toBe(150_001); expect(r.tax).toBe(27_594); }); // Case 4 — garde alternée: single, 1 shared-custody child, 40 000 € taxable. // P=1.25, q=32 000 → 2 703.99 ×1.25=3 379.99. Base 1×tax(40 000)=5 103.99. // Advantage 1 724 > quarter-part cap 903.50 → 5 103.99−903.50=4 200.49 → 4 200. it("4. garde alternée (quart de part plafonné)", () => { const r = computeIr({ household: { maritalStatus: "celibataire", children: 0, childrenGardeAlternee: 1 }, salaryTaxable: 44_444.44, ...noOpt, }); expect(r.taxableIncome).toBe(40_000); expect(r.tax).toBe(4_200); }); // Case 5 — PER capped: single, salary 111 111 € → −10% = 100 000 net. // PER paid 15 000, ceiling 10% × 100 000 = 10 000 → taxable 90 000. // tax = 18 477.09 + 0.41×5 423 = 20 700.52 → 20 701. it("5. PER plafonné à 10% du revenu", () => { const r = computeIr({ household: { maritalStatus: "celibataire", children: 0, childrenGardeAlternee: 0 }, salaryTaxable: 111_111.11, versementsPER: 15_000, ...{ fraisReels: undefined, dons: undefined }, }); expect(r.perDeduction).toBe(10_000); expect(r.taxableIncome).toBe(90_000); expect(r.tax).toBe(20_701); }); // Case 6 — impatrié (30% exemption): salary 88 888.89 → ×0.7 = 62 222.22 // → −10% = 56 000. tax = 1 977.69 + 0.30×26 421 = 9 903.99 → 9 904. it("6. régime impatrié art. 155 B", () => { const r = computeIr({ household: { maritalStatus: "celibataire", children: 0, childrenGardeAlternee: 0 }, salaryTaxable: 88_888.89, impatrie: true, ...noOpt, }); expect(r.taxableIncome).toBe(56_000); expect(r.tax).toBe(9_904); }); // Case 7 — donations: same base as case 4 without child (tax 5 103.99), // 1 500 € donated → 75%×1 000 + 66%×500 = 1 080 → 5 103.99−1 080=4 023.99 → 4 024. it("7. dons 75% puis 66%", () => { const r = computeIr({ household: { maritalStatus: "celibataire", children: 0, childrenGardeAlternee: 0 }, salaryTaxable: 44_444.44, dons: 1_500, ...{ fraisReels: undefined, versementsPER: undefined }, }); expect(r.donationReduction).toBe(1_080); expect(r.tax).toBe(4_024); }); // Case 8 — décote single: 20 000 € taxable → 924 gross. // décote = 897 − 0.4525×924 = 478.89 → tax 445.11 → 445. it("8. décote célibataire", () => { const r = computeIr({ household: { maritalStatus: "celibataire", children: 0, childrenGardeAlternee: 0 }, salaryTaxable: 22_222.22, ...noOpt, }); expect(r.tax).toBe(445); }); // Case 9 — below first bracket → zero tax. it("9. revenu sous la première tranche", () => { const r = computeIr({ household: { maritalStatus: "celibataire", children: 0, childrenGardeAlternee: 0 }, salaryTaxable: 12_000, ...noOpt, }); expect(r.tax).toBe(0); expect(r.averageRate).toBe(0); }); // Case 10 — couple, 1 resident + 1 shared-custody child, 70 000 € taxable. // P=2.75, q=25 454.55 → 0.11×13 854.55=1 524.00 ×2.75=4 191.00. // Base 2×tax(35 000)=2×3 603.99=7 207.98. Advantage 3 016.98 > cap // (1 807+903.5=2 710.5) → 7 207.98−2 710.5=4 497.48 → 4 497. it("10. couple, enfant + garde alternée, plafonnement mixte", () => { const r = computeIr({ household: { maritalStatus: "marie_pacse", children: 1, childrenGardeAlternee: 1 }, salaryTaxable: 77_777.78, ...noOpt, }); expect(r.taxableIncome).toBe(70_000); expect(r.tax).toBe(4_497); }); }); describe("computePortage — non-regression vs the official RD Portage workbook", () => { // Reference: Simulation_RD_PORTAGE_420.pdf (client document). // TJM 420 × 20 days, NDF 500 €, May 1 570 €, meal vouchers 13 €/day. it("reproduces the TJM 420 reference simulation within ±10 €", () => { const p = computePortage({ tjm: 420, days: 20, ndf: 500, cagnotteMay: 1_570, mealVouchers: true }); expect(p.fees).toBe(8_400); expect(p.managementFee).toBe(336); expect(p.insuranceTax).toBe(76); expect(p.available).toBe(5_918); expect(Math.abs(p.grossSalary - 4_065)).toBeLessThanOrEqual(10); expect(Math.abs(p.employerContributions - 1_854)).toBeLessThanOrEqual(10); expect(Math.abs(p.netSalary - 3_191)).toBeLessThanOrEqual(10); expect(Math.abs(p.netWithExpenses - 3_561)).toBeLessThanOrEqual(10); expect(Math.abs(p.netPerceived - 3_821)).toBeLessThanOrEqual(10); expect(Math.abs(p.globalCompensation - 5_391)).toBeLessThanOrEqual(10); expect(p.restitutionRate).toBeGreaterThan(0.63); expect(p.restitutionRate).toBeLessThan(0.66); }); // Règle RD (retours #4/#42 du 25/09) : NDF limitées à 30 % du SALAIRE BRUT. it("caps NDF at 30% of the gross salary", () => { const p = computePortage({ tjm: 400, days: 10, ndf: 3_000 }); expect(p.ndf).toBeLessThan(3_000); expect(p.ndf).toBeCloseTo(0.3 * p.grossSalary, -1); }); it("never produces a negative available account", () => { const p = computePortage({ tjm: 100, days: 2, ndf: 60, cagnotteMay: 500 }); expect(p.available).toBeGreaterThanOrEqual(0); }); }); describe("simulate — 3 scenarios", () => { it("optimised portage beats raw portage for a typical consultant", () => { const r = simulate({ status: "porte_ailleurs", tjmOrMonthlyGross: 500, daysPerYear: 210, household: { maritalStatus: "marie_pacse", children: 2, childrenGardeAlternee: 0 }, fraisReelsAnnual: 6_000, versementsPER: 5_000, }); const [actuel, portage, optimise] = r.scenarios; expect(actuel.id).toBe("actuel"); expect(optimise.disposable).toBeGreaterThan(portage.disposable); expect(r.economieAnnuelleEur).toBe(optimise.disposable - actuel.disposable); expect(r.economieRange.low).toBeLessThan(r.economieRange.high); }); /** * Ce test verrouillait auparavant `economieAnnuelleEur >= 0`, c'est-à-dire * l'écrêtage qui produisait BUG-02 : un micro-entrepreneur voyait toujours * « 0 € sur la table ». L'écart est désormais rendu signé — le test vérifie * qu'il est EXACT et que la fourchette reste ordonnée, quel que soit le signe. */ it("micro freelance: l'écart réel est négatif, exact, et la fourchette reste ordonnée", () => { const r = simulate({ status: "freelance_micro", tjmOrMonthlyGross: 450, daysPerYear: 200, household: { maritalStatus: "celibataire", children: 0, childrenGardeAlternee: 0 }, }); const [actuel, , optimise] = r.scenarios; // À revenu égal, la micro reste plus favorable : l'écart est négatif. expect(r.economieAnnuelleEur).toBeLessThan(0); // Plus aucun écrêtage : la valeur est exactement la différence calculée. expect(r.economieAnnuelleEur).toBe(optimise.disposable - actuel.disposable); // La fourchette reste ordonnée même avec un écart négatif. expect(r.economieRange.low).toBeLessThanOrEqual(r.economieRange.high); expect(r.economieRange.low).toBeLessThan(0); }); it("aucun scénario ne renvoie de valeur non finie sur des entrées dégradées", () => { for (const [tjm, days] of [[0, 200], [450, 0], [0, 0]] as [number, number][]) { const r = simulate({ status: "freelance_micro", tjmOrMonthlyGross: tjm, daysPerYear: days, household: { maritalStatus: "celibataire", children: 0, childrenGardeAlternee: 0 }, }); for (const s of r.scenarios) { expect(Number.isFinite(s.netPerceived)).toBe(true); expect(Number.isFinite(s.disposable)).toBe(true); expect(Number.isFinite(s.averageTaxRate)).toBe(true); } expect(Number.isFinite(r.economieAnnuelleEur)).toBe(true); } }); });