Test troublesome migration 0019

InvenTree/company/migrations/0019_auto_20200413_0642.py

@@ -1,14 +1,21 @@
 # Generated by Django 2.2.10 on 2020-04-13 06:42
 
+import sys
 import os
 from rapidfuzz import fuzz
 
 from django.db import migrations, connection
 from django.db.utils import OperationalError, ProgrammingError
 
+"""
+When this migration is tested by CI, it cannot accept user input.
+So a simplified version of the migration is implemented.
+"""
+TESTING = 'test' in sys.argv
 
 def clear():
-    os.system('cls' if os.name == 'nt' else 'clear')
+    if not TESTING:
+        os.system('cls' if os.name == 'nt' else 'clear')
 
 
 def reverse_association(apps, schema_editor):
@@ -222,23 +229,31 @@ def associate_manufacturers(apps, schema_editor):
         clear()
 
         # Present a list of options
-        print("----------------------------------")
+        if not TESTING:
+            print("----------------------------------")
+    
         print("Checking part [{pk}] ({idx} of {total})".format(pk=part_id, idx=idx+1, total=total))
-        print("Manufacturer name: '{n}'".format(n=name))
-        print("----------------------------------")
-        print("Select an option from the list below:")
+    
+        if not TESTING:
+            print("Manufacturer name: '{n}'".format(n=name))
+            print("----------------------------------")
+            print("Select an option from the list below:")
 
-        print("0) - Create new manufacturer '{n}'".format(n=name))
-        print("")
+            print("0) - Create new manufacturer '{n}'".format(n=name))
+            print("")
 
-        for i, m in enumerate(matches[:10]):
-            print("{i}) - Use manufacturer '{opt}'".format(i=i+1, opt=m))
+            for i, m in enumerate(matches[:10]):
+                print("{i}) - Use manufacturer '{opt}'".format(i=i+1, opt=m))
 
-        print("")
-        print("OR - Type a new custom manufacturer name")
+            print("")
+            print("OR - Type a new custom manufacturer name")
 
         while True:
-            response = str(input("> ")).strip()
+            if TESTING:
+                # When running unit tests, simply select the name of the part
+                response = '0'
+            else:
+                response = str(input("> ")).strip()
 
             # Attempt to parse user response as an integer
             try:
@@ -300,18 +315,19 @@ def associate_manufacturers(apps, schema_editor):
     print("")
     clear()
 
-    print("---------------------------------------")
-    print("The SupplierPart model needs to be migrated,")
-    print("as the new 'manufacturer' field maps to a 'Company' reference.")
-    print("The existing 'manufacturer_name' field will be used to match")
-    print("against possible companies.")
-    print("This process requires user input.")
-    print("")
-    print("Note: This process MUST be completed to migrate the database.")
-    print("---------------------------------------")
-    print("")
+    if not TESTING:
+        print("---------------------------------------")
+        print("The SupplierPart model needs to be migrated,")
+        print("as the new 'manufacturer' field maps to a 'Company' reference.")
+        print("The existing 'manufacturer_name' field will be used to match")
+        print("against possible companies.")
+        print("This process requires user input.")
+        print("")
+        print("Note: This process MUST be completed to migrate the database.")
+        print("---------------------------------------")
+        print("")
 
-    input("Press <ENTER> to continue.")
+        input("Press <ENTER> to continue.")
 
     clear()
 

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')