Allow zero-euro line item amounts

tests/test_validator.py

@@ -1,6 +1,5 @@
 """Tests for ZUGFeRD validator using TDD approach."""
 
-import pytest
 from src.models import (
     XmlData,
     Supplier,
@@ -9,8 +8,6 @@ from src.models import (
     Totals,
     VatBreakdown,
     PaymentTerms,
-    ErrorDetail,
-    ValidationResult,
     ValidateRequest,
 )
 from src.validator import (
@@ -352,8 +349,8 @@ class TestValidatePflichtfelder:
         assert any(e.field == "line_items[0].quantity" for e in errors)
         assert any(e.severity == "critical" for e in errors)
 
-    def test_missing_line_item_unit_price_critical(self):
-        """Missing line_item.unit_price (zero) should produce critical error."""
+    def test_zero_euro_line_item_amounts_allowed(self):
+        """Zero-valued line item prices should count as present."""
         xml_data = XmlData(
             invoice_number="INV001",
             invoice_date="2024-01-15",
@@ -366,6 +363,29 @@ class TestValidatePflichtfelder:
                     quantity=1.0,
                     unit="Stück",
                     unit_price=0.0,
+                    line_total=0.0,
+                )
+            ],
+            totals=Totals(line_total_sum=10.0, net=10.0, vat_total=19.0, gross=29.0),
+        )
+        errors = validate_pflichtfelder(xml_data)
+        assert not any(e.field == "line_items[0].unit_price" for e in errors)
+        assert not any(e.field == "line_items[0].line_total" for e in errors)
+
+    def test_missing_line_item_unit_price_critical(self):
+        """Missing line_item.unit_price should produce critical error."""
+        xml_data = XmlData(
+            invoice_number="INV001",
+            invoice_date="2024-01-15",
+            supplier=Supplier(name="Test Supplier GmbH", vat_id="DE123456789"),
+            buyer=Buyer(name="Test Buyer AG"),
+            line_items=[
+                LineItem(
+                    position=1,
+                    description="Test Product",
+                    quantity=1.0,
+                    unit="Stück",
+                    unit_price=None,
                     line_total=10.0,
                 )
             ],
@@ -376,7 +396,7 @@ class TestValidatePflichtfelder:
         assert any(e.severity == "critical" for e in errors)
 
     def test_missing_line_item_line_total_critical(self):
-        """Missing line_item.line_total (zero) should produce critical error."""
+        """Missing line_item.line_total should produce critical error."""
         xml_data = XmlData(
             invoice_number="INV001",
             invoice_date="2024-01-15",
@@ -389,7 +409,7 @@ class TestValidatePflichtfelder:
                     quantity=1.0,
                     unit="Stück",
                     unit_price=10.0,
-                    line_total=0.0,
+                    line_total=None,
                 )
             ],
             totals=Totals(line_total_sum=10.0, net=10.0, vat_total=0.0, gross=10.0),
@@ -499,7 +519,7 @@ class TestValidateBetraege:
         errors = validate_betraege(xml_data)
         assert any(e.error_code == "calculation_mismatch" for e in errors)
         assert any(
-            "line_total" in e.field
+            e.field is not None and "line_total" in e.field
             for e in errors
             if e.error_code == "calculation_mismatch"
         )
@@ -597,7 +617,7 @@ class TestValidateBetraege:
             ),
         )
         errors = validate_betraege(xml_data)
-        assert any("vat_breakdown" in e.field for e in errors)
+        assert any(e.field is not None and "vat_breakdown" in e.field for e in errors)
         assert any(e.error_code == "calculation_mismatch" for e in errors)
 
     def test_totals_vat_total_mismatch(self):
@@ -1040,6 +1060,7 @@ class TestValidateInvoice:
         result = validate_invoice(request)
         assert result.is_valid is True
         assert len(result.errors) == 0
+        assert result.summary is not None
         assert result.summary["checks_passed"] == 2
 
     def test_warnings_not_critical(self):
@@ -1134,6 +1155,7 @@ class TestValidateInvoice:
         )
         result = validate_invoice(request)
         # Should have errors from PDF comparison
+        assert result.summary is not None
         assert result.summary["total_checks"] == 1
 
     def test_validation_time_populated(self):
@@ -1187,5 +1209,6 @@ class TestValidateInvoice:
         )
         result = validate_invoice(request)
         # Should handle gracefully - no errors from invalid check
+        assert result.summary is not None
         assert result.summary["total_checks"] == 0
         assert result.is_valid is True  # No critical errors