Salary module (#245)

* feat: implement salary module with personnummer encryption, salary entries, tax tables, and AGI tracking - Added personnummer encryption and decryption functions for secure storage. - Created salary entries handling for journal entries including gross salary, tax withholding, and employer contributions. - Implemented tax table lookup functionality for calculating tax amounts based on monthly income. - Developed SQL migration for salary module including tables for payroll configuration, tax rates, employees, salary runs, salary run employees, salary line items, and AGI declarations. - Established row-level security policies for all new tables to ensure company-scoped access. * feat: add salary calculation modules for 2026 - Implemented engångsskatt calculation for one-time payments with tax brackets. - Added löneväxling functionality for salary sacrifice to pension, including employer savings and warnings. - Created pain.001 generator for salary batch payments in compliance with Swedish banking standards. - Developed PDF template for payslips, including detailed breakdowns and employer costs. - Generated seed data for Swedish tax tables for 2026, including SQL insert statements. - Implemented traktamente calculations for per diem and mileage allowances, adhering to Skatteverket regulations. - Added seed script for populating tax tables in the database. * feat: Update meal reduction percentages in traktamente calculation fix: Remove obsolete seed script for 2026 tax tables feat: Extend SalaryRunStatus type to include 'corrected' status feat: Implement KU10 XML generation endpoint for annual employee income statements feat: Add endpoint for creating corrections to booked salary runs feat: Implement endpoint for sending payslip PDFs to employees feat: Create KU10 XML generator for annual reporting feat: Add salary transaction matcher for auto-linking bank transactions to salary entries chore: Add database migration for salary correction support * feat: replace select elements with custom Select component for employment and salary types * feat: enhance salary calculations with pension entry and avgifter category support
2026-04-15 11:17:39 +02:00
parent b387a77bfd
commit 04dbb31d7e
78 changed files with 10529 additions and 14 deletions
@@ -0,0 +1,370 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { calculateSalary, calculateKarensavdrag, calculateSjuklon, calculateAvgifterRate } from '../calculation-engine'
+import type { PayrollConfig } from '../payroll-config'
+import type { TaxTableRate } from '../tax-tables'
+
+// Mock personnummer module
+vi.mock('../personnummer', () => ({
+  decryptPersonnummer: (encrypted: string) => {
+    // Return mock personnummer based on encrypted value
+    if (encrypted === 'mock_old_person') return '193501011234'
+    if (encrypted === 'mock_young_person') return '200301011234'
+    if (encrypted === 'mock_senior_person') return '195801011234'
+    return '199001011234' // Default: born 1990
+  },
+  calculateAgeAtYearStart: (pnr: string, year: number) => {
+    const birthYear = parseInt(pnr.slice(0, 4))
+    return year - birthYear
+  },
+}))
+
+const config2026: PayrollConfig = {
+  configYear: 2026,
+  avgifterTotal: 0.3142,
+  avgifterAlderspension: 0.1021,
+  avgifterSjukforsakring: 0.0355,
+  avgifterForaldraforsakring: 0.0200,
+  avgifterEfterlevandepension: 0.0030,
+  avgifterArbetsmarknad: 0.0264,
+  avgifterArbetsskada: 0.0010,
+  avgifterAllmanLoneavgift: 0.1262,
+  avgifterReduced65plus: 0.1021,
+  avgifterYouthRate: 0.2081,
+  avgifterYouthSalaryCap: 25000,
+  avgifterVaxaStodRate: 0.1021,
+  avgifterVaxaStodCap: 35000,
+  avgifterMinimumAnnual: 1000,
+  egenavgifterTotal: 0.2897,
+  slpRate: 0.2426,
+  prisbasbelopp: 59200,
+  inkomstbasbelopp: 83400,
+  maxPgi: 625500,
+  sgiCeiling: 592000,
+  statligSkattBrytpunkt: 660400,
+  traktamenteHeldag: 300,
+  traktamenteHalvdag: 150,
+  traktamenteNatt: 150,
+  milersattningEgenBil: 25,
+  milersattningFormansbilFossil: 12,
+  milersattningFormansbilEl: 9.50,
+  kostformanHeldag: 310,
+  kostformanLunch: 124,
+  kostformanFrukost: 62,
+  friskvardCap: 5000,
+  bilformanSlr: 0.0255,
+  sjuklonRate: 0.80,
+  karensavdragFactor: 0.20,
+  maxKarensavdragPerYear: 10,
+  reducedAvgiftAge: 67,
+}
+
+const emptyTaxRates: TaxTableRate[] = []
+
+function makeBasicInput(overrides = {}) {
+  return {
+    employmentType: 'employee' as const,
+    salaryType: 'monthly' as const,
+    monthlySalary: 40000,
+    employmentDegree: 100,
+    taxTableNumber: null,
+    taxColumn: 1,
+    isSidoinkomst: false,
+    jamkningPercentage: null,
+    jamkningValidFrom: null,
+    jamkningValidTo: null,
+    fSkattStatus: 'a_skatt',
+    personnummer: 'mock_standard',
+    paymentDate: '2026-04-25',
+    vacationRule: 'procentregeln' as const,
+    vacationDaysPerYear: 25,
+    semestertillaggRate: 0.0043,
+    vaxaStodEligible: false,
+    vaxaStodStart: null,
+    vaxaStodEnd: null,
+    lineItems: [],
+    ...overrides,
+  }
+}
+
+describe('calculateSalary', () => {
+  it('calculates basic monthly salary correctly', () => {
+    const result = calculateSalary(makeBasicInput(), config2026, emptyTaxRates)
+
+    expect(result.grossSalary).toBe(40000)
+    // With no tax table, falls back to 30%
+    expect(result.taxWithheld).toBe(12000)
+    expect(result.netSalary).toBe(28000)
+    expect(result.avgifterRate).toBe(0.3142)
+    expect(result.avgifterAmount).toBe(Math.round(40000 * 0.3142 * 100) / 100)
+    expect(result.vacationAccrual).toBe(Math.round(40000 * 0.12 * 100) / 100)
+    expect(result.steps.length).toBeGreaterThan(0)
+  })
+
+  it('applies employment degree', () => {
+    const result = calculateSalary(
+      makeBasicInput({ employmentDegree: 50 }),
+      config2026,
+      emptyTaxRates
+    )
+
+    expect(result.grossSalary).toBe(20000)
+    expect(result.taxWithheld).toBe(6000) // 30% of 20000
+    expect(result.netSalary).toBe(14000)
+  })
+
+  it('calculates hourly salary', () => {
+    const result = calculateSalary(
+      makeBasicInput({
+        salaryType: 'hourly',
+        monthlySalary: 0,
+        hourlyRate: 250,
+        hoursWorked: 160,
+      }),
+      config2026,
+      emptyTaxRates
+    )
+
+    expect(result.grossSalary).toBe(40000) // 250 * 160
+  })
+
+  it('applies sidoinkomst flat 30%', () => {
+    const result = calculateSalary(
+      makeBasicInput({ isSidoinkomst: true }),
+      config2026,
+      emptyTaxRates
+    )
+
+    expect(result.taxWithheld).toBe(12000) // 30% of 40000
+  })
+
+  it('applies f-skatt with 0% withholding', () => {
+    const result = calculateSalary(
+      makeBasicInput({ fSkattStatus: 'f_skatt' }),
+      config2026,
+      emptyTaxRates
+    )
+
+    expect(result.taxWithheld).toBe(0)
+    expect(result.netSalary).toBe(40000)
+  })
+
+  it('applies unverified flat 30%', () => {
+    const result = calculateSalary(
+      makeBasicInput({ fSkattStatus: 'not_verified' }),
+      config2026,
+      emptyTaxRates
+    )
+
+    expect(result.taxWithheld).toBe(12000)
+  })
+
+  it('applies jämkning when valid', () => {
+    const result = calculateSalary(
+      makeBasicInput({
+        jamkningPercentage: 15,
+        jamkningValidFrom: '2026-01-01',
+        jamkningValidTo: '2026-12-31',
+      }),
+      config2026,
+      emptyTaxRates
+    )
+
+    expect(result.taxWithheld).toBe(6000) // 15% of 40000
+  })
+
+  it('does not apply jämkning when outside date range', () => {
+    const result = calculateSalary(
+      makeBasicInput({
+        jamkningPercentage: 15,
+        jamkningValidFrom: '2025-01-01',
+        jamkningValidTo: '2025-12-31',
+        paymentDate: '2026-04-25',
+      }),
+      config2026,
+      emptyTaxRates
+    )
+
+    // Should fall back to 30% since jämkning expired
+    expect(result.taxWithheld).toBe(12000)
+  })
+
+  it('handles line item additions', () => {
+    const result = calculateSalary(
+      makeBasicInput({
+        lineItems: [
+          { itemType: 'bonus', amount: 5000, isTaxable: true, isAvgiftBasis: true, isVacationBasis: true, isGrossDeduction: false, isNetDeduction: false },
+        ],
+      }),
+      config2026,
+      emptyTaxRates
+    )
+
+    expect(result.grossSalary).toBe(45000) // 40000 + 5000
+    expect(result.taxWithheld).toBe(13500) // 30% of 45000
+  })
+
+  it('applies gross deductions before tax', () => {
+    const result = calculateSalary(
+      makeBasicInput({
+        lineItems: [
+          { itemType: 'gross_deduction_pension', amount: -5000, isTaxable: true, isAvgiftBasis: true, isVacationBasis: false, isGrossDeduction: true, isNetDeduction: false },
+        ],
+      }),
+      config2026,
+      emptyTaxRates
+    )
+
+    expect(result.grossSalary).toBe(35000) // 40000 - 5000
+    expect(result.grossDeductions).toBe(5000)
+    expect(result.taxWithheld).toBe(10500) // 30% of 35000 (tax on reduced amount)
+  })
+
+  it('applies net deductions after tax', () => {
+    const result = calculateSalary(
+      makeBasicInput({
+        lineItems: [
+          { itemType: 'net_deduction_advance', amount: -3000, isTaxable: false, isAvgiftBasis: false, isVacationBasis: false, isGrossDeduction: false, isNetDeduction: true },
+        ],
+      }),
+      config2026,
+      emptyTaxRates
+    )
+
+    expect(result.grossSalary).toBe(40000) // Unaffected
+    expect(result.taxWithheld).toBe(12000) // 30% of 40000 (tax on full amount)
+    expect(result.netDeductions).toBe(3000)
+    expect(result.netSalary).toBe(25000) // 40000 - 12000 - 3000
+  })
+
+  it('calculates vacation accrual with procentregeln', () => {
+    const result = calculateSalary(
+      makeBasicInput({ vacationRule: 'procentregeln', vacationDaysPerYear: 25 }),
+      config2026,
+      emptyTaxRates
+    )
+
+    expect(result.vacationAccrual).toBe(Math.round(40000 * 0.12 * 100) / 100)
+  })
+
+  it('uses 14.4% for 30+ vacation days', () => {
+    const result = calculateSalary(
+      makeBasicInput({ vacationRule: 'procentregeln', vacationDaysPerYear: 30 }),
+      config2026,
+      emptyTaxRates
+    )
+
+    expect(result.vacationAccrual).toBe(Math.round(40000 * 0.144 * 100) / 100)
+  })
+
+  it('adds benefit values to tax base but not gross', () => {
+    const result = calculateSalary(
+      makeBasicInput({
+        lineItems: [
+          { itemType: 'benefit_car', amount: 3000, isTaxable: true, isAvgiftBasis: true, isVacationBasis: false, isGrossDeduction: false, isNetDeduction: false },
+        ],
+      }),
+      config2026,
+      emptyTaxRates
+    )
+
+    expect(result.grossSalary).toBe(40000) // Benefits don't add to gross
+    expect(result.benefitValues).toBe(3000)
+    expect(result.taxableIncome).toBe(43000) // gross + benefits
+    expect(result.taxWithheld).toBe(12900) // 30% of 43000
+    expect(result.netSalary).toBe(27100) // 40000 - 12900
+  })
+
+  it('includes employer cost calculation', () => {
+    const result = calculateSalary(makeBasicInput(), config2026, emptyTaxRates)
+
+    const expectedAvgifter = Math.round(40000 * 0.3142 * 100) / 100
+    const expectedVacation = Math.round(40000 * 0.12 * 100) / 100
+    const expectedVacationAvgifter = Math.round(expectedVacation * 0.3142 * 100) / 100
+    const expectedCost = Math.round((40000 + expectedAvgifter + expectedVacation + expectedVacationAvgifter) * 100) / 100
+
+    expect(result.totalEmployerCost).toBe(expectedCost)
+  })
+})
+
+describe('calculateKarensavdrag', () => {
+  it('calculates 20% of weekly sjuklön', () => {
+    // Formula: 20% × (40000 × 12/52 × 0.80)
+    const expected = Math.round(0.20 * (40000 * 12 / 52 * 0.80) * 100) / 100
+    expect(calculateKarensavdrag(40000, config2026)).toBe(expected)
+  })
+})
+
+describe('calculateSjuklon', () => {
+  it('calculates karensavdrag + sjuklön for sick days', () => {
+    const result = calculateSjuklon(40000, 5, config2026)
+
+    expect(result.karensavdrag).toBeGreaterThan(0)
+    expect(result.sjuklon).toBeGreaterThan(0)
+    expect(result.steps.length).toBeGreaterThan(0)
+  })
+
+  it('handles 1-day sick leave (karens only)', () => {
+    const result = calculateSjuklon(40000, 1, config2026)
+
+    expect(result.karensavdrag).toBeGreaterThan(0)
+    expect(result.sjuklon).toBe(0) // No sjuklön for day 1
+  })
+
+  it('caps at 13 sjuklön days (day 2-14)', () => {
+    const result14 = calculateSjuklon(40000, 14, config2026)
+    const result20 = calculateSjuklon(40000, 20, config2026)
+
+    // sjuklön should be the same for 14 and 20 days (capped at day 14)
+    expect(result14.sjuklon).toBe(result20.sjuklon)
+  })
+})
+
+describe('calculateAvgifterRate', () => {
+  it('returns standard rate for normal employee', () => {
+    const result = calculateAvgifterRate(
+      makeBasicInput(),
+      config2026,
+      2026
+    )
+
+    expect(result.rate).toBe(0.3142)
+    expect(result.category).toBe('standard')
+  })
+
+  it('returns reduced rate for 67+ employee', () => {
+    const result = calculateAvgifterRate(
+      makeBasicInput({ personnummer: 'mock_senior_person' }),
+      config2026,
+      2026
+    )
+
+    expect(result.rate).toBe(0.1021)
+    expect(result.category).toBe('reduced_65plus')
+  })
+
+  it('returns 0% for born ≤1937', () => {
+    const result = calculateAvgifterRate(
+      makeBasicInput({ personnummer: 'mock_old_person' }),
+      config2026,
+      2026
+    )
+
+    expect(result.rate).toBe(0)
+    expect(result.category).toBe('exempt')
+  })
+
+  it('returns växa-stöd rate when eligible', () => {
+    const result = calculateAvgifterRate(
+      makeBasicInput({
+        vaxaStodEligible: true,
+        vaxaStodStart: '2025-01-01',
+        vaxaStodEnd: '2026-12-31',
+      }),
+      config2026,
+      2026
+    )
+
+    expect(result.rate).toBe(0.1021)
+    expect(result.category).toBe('vaxa_stod')
+  })
+})