Add tests for the new fields

Author: aleksanb

test-data/typecheck/fields.test

@@ -37,6 +37,22 @@ reveal_type(user.name)  # E: Revealed type is 'builtins.str'
 reveal_type(user.slug)  # E: Revealed type is 'builtins.str'
 reveal_type(user.text)  # E: Revealed type is 'builtins.str'
 
+[CASE test_model_field_classes_from_exciting_locations]
+from django.db import models
+from django.contrib.postgres import fields as pg_fields
+from psycopg2.extras import DateTimeTZRange
+from decimal import Decimal
+
+class Booking(models.Model):
+    id = models.AutoField(primary_key=True)
+    time_range = pg_fields.DateTimeRangeField(null=False)
+    some_decimal = models.DecimalField(max_digits=10, decimal_places=5)
+
+booking = Booking()
+reveal_type(user.id)  # E: Revealed type is 'builtins.int'
+reveal_type(booking.time_range)  # E: Revealed type is 'DateTimeTZRange'
+reveal_type(booking.some_decimal)  # E: Revealed type is 'Decimal'
+
 [CASE test_add_id_field_if_no_primary_key_defined]
 from django.db import models