Test troublesome migration 0019

InvenTree/company/test_migrations.py

@@ -0,0 +1,80 @@
+"""
+Tests for the company model database migrations
+"""
+
+from django_test_migrations.contrib.unittest_case import MigratorTestCase
+
+
+class TestManufacturerField(MigratorTestCase):
+    """
+    Tests for migration 0019 which migrates from old 'manufacturer_name' field to new 'manufacturer' field
+    """
+
+    migrate_from = ('company', '0018_supplierpart_manufacturer')
+    migrate_to = ('company', '0019_auto_20200413_0642')
+
+    def prepare(self):
+        """
+        Prepare the database by adding some test data 'before' the change:
+
+        - Part object
+        - Company object (supplier)
+        - SupplierPart object
+        """
+        
+        Part = self.old_state.apps.get_model('part', 'part')
+        Company = self.old_state.apps.get_model('company', 'company')
+        SupplierPart = self.old_state.apps.get_model('company', 'supplierpart')
+
+        # Create an initial part
+        part = Part.objects.create(
+            name='Screw',
+            description='A single screw'
+        )
+
+        # Create a company to act as the supplier
+        supplier = Company.objects.create(
+            name='Supplier',
+            description='A supplier of parts',
+            is_supplier=True,
+            is_customer=False,
+        )
+
+        # Add some SupplierPart objects
+        SupplierPart.objects.create(
+            part=part,
+            supplier=supplier,
+            SKU='SCREW.001',
+            manufacturer_name='ACME',
+        )
+
+        SupplierPart.objects.create(
+            part=part,
+            supplier=supplier,
+            SKU='SCREW.002',
+            manufacturer_name='Zero Corp'
+        )
+
+        self.assertEqual(Company.objects.count(), 1)
+
+    def test_company_objects(self):
+        """
+        Test that the new companies have been created successfully
+        """
+
+        # Two additional company objects should have been created
+        Company = self.new_state.apps.get_model('company', 'company')
+        self.assertEqual(Company.objects.count(), 3)
+
+        # The new company/ies must be marked as "manufacturers"
+        acme = Company.objects.get(name='ACME')
+        self.assertTrue(acme.is_manufacturer)
+
+        SupplierPart = self.new_state.apps.get_model('company', 'supplierpart')
+        parts = SupplierPart.objects.filter(manufacturer=acme)
+        self.assertEqual(parts.count(), 1)
+        part = parts.first()
+
+        # Checks on the SupplierPart object
+        self.assertEqual(part.manufacturer_name, 'ACME')
+        self.assertEqual(part.manufacturer.name, 'ACME')