Credit and Debt plus reason attribute inide register

apps/edr-freight-api/src/modules/billing/eims-invoice.mapper.spec.ts

@@ -212,6 +212,59 @@ describe("toEimsInvoice", () => {
     expect(() => toEimsInvoice(invoice({ issuedAt: null }), seller, context())).toThrow(/not issued/);
   });
 
+  describe("debit/credit notes — confirmed by MoR support, same /v1/register endpoint", () => {
+    it("defaults DocumentDetails.Type to INV with no Reason field", () => {
+      const doc = toEimsInvoice(invoice(), seller, context());
+      expect(doc.DocumentDetails.Type).toBe("INV");
+      expect(doc.DocumentDetails).not.toHaveProperty("Reason");
+    });
+
+    it("files a credit note with Type, Reason and RelatedDocument", () => {
+      const doc = toEimsInvoice(
+        invoice(),
+        seller,
+        context({
+          documentType: "CRE",
+          reason: "Overbilled freight charge",
+          relatedDocument: "9fe9bbbece6ab76c112b617534e6aac7aa8b819d5be79f4d3d088ed2e887b2e0",
+        }),
+      );
+      expect(doc.DocumentDetails).toMatchObject({ Type: "CRE", Reason: "Overbilled freight charge" });
+      expect(doc.ReferenceDetails.RelatedDocument).toBe(
+        "9fe9bbbece6ab76c112b617534e6aac7aa8b819d5be79f4d3d088ed2e887b2e0",
+      );
+    });
+
+    it("files a debit note the same way", () => {
+      const doc = toEimsInvoice(
+        invoice(),
+        seller,
+        context({ documentType: "DEB", reason: "Additional handling fee", relatedDocument: "IRN-1" }),
+      );
+      expect(doc.DocumentDetails).toMatchObject({ Type: "DEB", Reason: "Additional handling fee" });
+    });
+
+    it("throws when a credit/debit note has no reason", () => {
+      expect(() =>
+        toEimsInvoice(
+          invoice(),
+          seller,
+          context({ documentType: "CRE", reason: null, relatedDocument: "IRN-1" }),
+        ),
+      ).toThrow(/needs a reason/);
+    });
+
+    it("throws when a credit/debit note has no relatedDocument", () => {
+      expect(() =>
+        toEimsInvoice(
+          invoice(),
+          seller,
+          context({ documentType: "CRE", reason: "Overbilled", relatedDocument: null }),
+        ),
+      ).toThrow(/needs.*relatedDocument/);
+    });
+  });
+
   it("throws when the lines do not sum to the invoice total", () => {
     expect(() => toEimsInvoice(invoice({ totalAmount: "9000.00" }), seller, context())).toThrow(
       /lines sum to 11000 but the invoice total is 9000/,