Barcode Refactor (#3640)

* define a simple model mixin class for barcode

* Adds generic function for assigning a barcode to a model instance

* StockItem model now implements the BarcodeMixin class

* Implement simple unit tests for new code

* Fix unit tests

* Data migration for uid field

* Remove references to old 'uid' field

* Migration for removing old uid field from StockItem model

* Bump API version

* Change lookup_barcode to be a classmethod

* Change barcode_model_type to be a class method

* Cleanup for generic barcode scan and assign API:

- Raise ValidationError as appropriate
- Improved unit testing
- Groundwork for future generic implementation

* Further unit tests for barcode scanning

* Adjust error messages for compatibility

* Unit test fix

* Fix hash_barcode function

- Add unit tests to ensure it produces the same results as before the refactor

* Add BarcodeMixin to Part model

* Remove old format_barcode function from Part model

* Further fixes for unit tests

* Add support for assigning arbitrary barcode to Part instance

- Simplify barcode API
- Add more unit tests

* More unit test fixes

* Update unit test

* Adds generic endpoint for unassigning barcode data

* Update web dialog for unlinking a barcode

* Template cleanup

* Add Barcode mixin to StockLocation class

* Add some simple unit tests for new model mixin

* Support assigning / unassigning barcodes for StockLocation

* remove failing outdated test

* Update template to integrate new barcode support for StockLocation

* Add BarcodeMixin to SupplierPart model

* Adds QR code view for SupplierPart

* Major simplification of barcode API endpoints

- Separate existing barcode plugin into two separate classes
- Simplify and consolidate the response from barcode scanning
- Update unit testing

* Yet more unit test fixes

* Yet yet more unit test fixes

InvenTree/part/test_part.py

@@ -144,6 +144,15 @@ class PartTest(TestCase):
 
         Part.objects.rebuild()
 
+    def test_barcode_mixin(self):
+        """Test the barcode mixin functionality"""
+
+        self.assertEqual(Part.barcode_model_type(), 'part')
+
+        p = Part.objects.get(pk=1)
+        barcode = p.format_barcode(brief=True)
+        self.assertEqual(barcode, '{"part": 1}')
+
     def test_tree(self):
         """Test that the part variant tree is working properly"""
         chair = Part.objects.get(pk=10000)
@@ -243,7 +252,7 @@ class PartTest(TestCase):
         """Test barcode format functionality"""
         barcode = self.r1.format_barcode(brief=False)
         self.assertIn('InvenTree', barcode)
-        self.assertIn(self.r1.name, barcode)
+        self.assertIn('"part": {"id": 3}', barcode)
 
     def test_copy(self):
         """Test that we can 'deep copy' a Part instance"""