Matching invoices to purchase orders

src/matching/ matches the lines of a canonical invoice to purchase orders (two-way) and, with goods receipts, to what was received (three-way). Orders come from a small JSON model (PurchaseOrder: id, currency, lines[] with id, description, sellerItemId, buyerItemId, standardItemId, quantity, unit, unitPrice, baseQuantity, vat, and invoicedQuantity for what earlier invoices already billed) or from a UBL 2.1 Order / Peppol BIS Order 3 XML (parseOrder). Receipts are [{ "poId": "PO-1", "lines": [{ "lineId": "1", "quantity": "6" }] }].

Per invoice line, in this order: order-line reference (BT-132, within the order named by BT-13 or by the line itself, as Svefaktura’s BuyersID), item identifiers (seller, buyer, standard/GTIN), line relations (a markup or discount follows the lines it applies to; text-only lines are ignored), and description similarity as a last resort. Each match carries its method, confidence and variances (quantity, unit price, line total, VAT) against the tolerances you set ({ "unitPrice": { "percent": "2" }, "quantity": { "absolute": "1" } }; a limit given as both absolute and percent must hold in both; no tolerance means zero). The result also lists unmatched invoice lines, over-invoiced order lines and, with receipts, order lines not yet received, and a verdict: match, within-tolerance or needs-review. Description-only and low-confidence matches always need review. Fewer units than expected is partial invoicing, not a variance error. A credit note is held against what has been invoiced, at the order price.

import { convert, matching } from 'eu-einvoice-canonical';
const r = await convert(bytes, 'inv.xml', undefined, { relations: true });
const result = matching.matchInvoice(invoice, [matching.parseOrder(orderXml)], { tolerances: { unitPrice: { percent: '2' } } });