New Base func

lib/bookkeeping/__tests__/engine.test.ts

@@ -0,0 +1,64 @@
+import { describe, it, expect } from 'vitest'
+import { validateBalance } from '../engine'
+import type { CreateJournalEntryLineInput } from '@/types'
+
+describe('validateBalance', () => {
+  it('balanced entry (debit == credit) → valid: true', () => {
+    const lines: CreateJournalEntryLineInput[] = [
+      { account_number: '1930', debit_amount: 1000, credit_amount: 0 },
+      { account_number: '3001', debit_amount: 0, credit_amount: 1000 },
+    ]
+
+    const result = validateBalance(lines)
+    expect(result.valid).toBe(true)
+    expect(result.totalDebit).toBe(1000)
+    expect(result.totalCredit).toBe(1000)
+  })
+
+  it('unbalanced entry → valid: false', () => {
+    const lines: CreateJournalEntryLineInput[] = [
+      { account_number: '1930', debit_amount: 1000, credit_amount: 0 },
+      { account_number: '3001', debit_amount: 0, credit_amount: 500 },
+    ]
+
+    const result = validateBalance(lines)
+    expect(result.valid).toBe(false)
+    expect(result.totalDebit).toBe(1000)
+    expect(result.totalCredit).toBe(500)
+  })
+
+  it('zero amounts → valid: false (roundedDebit must be > 0)', () => {
+    const lines: CreateJournalEntryLineInput[] = [
+      { account_number: '1930', debit_amount: 0, credit_amount: 0 },
+      { account_number: '3001', debit_amount: 0, credit_amount: 0 },
+    ]
+
+    const result = validateBalance(lines)
+    expect(result.valid).toBe(false)
+    expect(result.totalDebit).toBe(0)
+    expect(result.totalCredit).toBe(0)
+  })
+
+  it('floating point edge case (33.33 + 33.33 + 33.34) → valid: true', () => {
+    const lines: CreateJournalEntryLineInput[] = [
+      { account_number: '1930', debit_amount: 33.33, credit_amount: 0 },
+      { account_number: '1930', debit_amount: 33.33, credit_amount: 0 },
+      { account_number: '1930', debit_amount: 33.34, credit_amount: 0 },
+      { account_number: '3001', debit_amount: 0, credit_amount: 100 },
+    ]
+
+    const result = validateBalance(lines)
+    expect(result.valid).toBe(true)
+    expect(result.totalDebit).toBe(100)
+    expect(result.totalCredit).toBe(100)
+  })
+
+  it('single line (only debit, no credit) → valid: false', () => {
+    const lines: CreateJournalEntryLineInput[] = [
+      { account_number: '1930', debit_amount: 500, credit_amount: 0 },
+    ]
+
+    const result = validateBalance(lines)
+    expect(result.valid).toBe(false)
+  })
+})