Document Modules Code Review Checklist

Use this checklist when adding or modifying document types (Sale, Order, Quote, Bill, Invoice, Return, Credit Note) or when changing calculation logic.

Calculation Architecture

• Uses LineItemTaxService for tax and total calculations (no duplicate logic)
• Uses product/source tax definitions when available (not just snapshots)
• Outputs line items in DocumentLineItemShape for consistent frontend display
• Tax-inclusive: grandTotal = sum(lineGross) (do NOT add tax again)

Validation

• Header total is computed from line items (never trusted from client)
• When client sends total: call validateHeaderTotalMatchesLineTotals before persist
• recomputeAndUpdateOrderTotals (or equivalent) called after every item mutation
• Sanity check: computed total is finite and non-negative before persist

Tests

• Integration test verifies totals match for equivalent line items across documents
• Unit tests cover discount + tax scenarios

References

• ADR-002: Document Calculations Architecture
• DocumentCalculationsModule / LineItemTaxService
• document-line-item.types.ts