Fixed #28393 -- Added helpful error messages for invalid AutoField/FloatField/IntegerField values.

Co-authored-by: Diederik van der Boor <vdboor@edoburu.nl>
Co-authored-by: Nick Pope <nick.pope@flightdataservices.com>

tests/model_fields/test_autofield.py

@@ -0,0 +1,32 @@
+from django.test import TestCase
+
+from .models import AutoModel, BigAutoModel, SmallAutoModel
+
+
+class AutoFieldTests(TestCase):
+    model = AutoModel
+
+    def test_invalid_value(self):
+        tests = [
+            (TypeError, ()),
+            (TypeError, []),
+            (TypeError, {}),
+            (TypeError, set()),
+            (TypeError, object()),
+            (TypeError, complex()),
+            (ValueError, 'non-numeric string'),
+            (ValueError, b'non-numeric byte-string'),
+        ]
+        for exception, value in tests:
+            with self.subTest(value=value):
+                msg = "Field 'value' expected a number but got %r." % (value,)
+                with self.assertRaisesMessage(exception, msg):
+                    self.model.objects.create(value=value)
+
+
+class BigAutoFieldTests(AutoFieldTests):
+    model = BigAutoModel
+
+
+class SmallAutoFieldTests(AutoFieldTests):
+    model = SmallAutoModel