Fix bugs with non default hll fields

The implementation of hll fields with non default values was broken
as it passed the hll kwargs down to the Field without removing them.

Note there is a wider batch of work to support non default values in
the library as new hll fields created, such as HllEmpty need to match
the settings of the field being written to. I have not attempted to
address this, and have simply used the hll_set_defaults to control
things in the tests.

src/django_pg_hll/fields.py

@@ -27,10 +27,10 @@ class HllField(BinaryField):
     }
 
     def __init__(self, *args, **kwargs):
-        self._log2m = kwargs.get('log2m', self.custom_params['log2m'])
-        self._regwidth = kwargs.get('regwidth', self.custom_params['regwidth'])
-        self._expthresh = kwargs.get('expthresh', self.custom_params['expthresh'])
-        self._sparseon = kwargs.get('sparseon', self.custom_params['sparseon'])
+        self._log2m = kwargs.pop('log2m', self.custom_params['log2m'])
+        self._regwidth = kwargs.pop('regwidth', self.custom_params['regwidth'])
+        self._expthresh = kwargs.pop('expthresh', self.custom_params['expthresh'])
+        self._sparseon = kwargs.pop('sparseon', self.custom_params['sparseon'])
 
         super(HllField, self).__init__(*args, **kwargs)
 
@@ -40,7 +40,7 @@ def deconstruct(self):
         # Only include kwarg if it's not the default
         for param_name, default in self.custom_params.items():
             if getattr(self, '_%s' % param_name) != default:
-                kwargs[name] = getattr(self, '_%s' % param_name)
+                kwargs[param_name] = getattr(self, '_%s' % param_name)
 
         return name, path, args, kwargs
 

tests/migrations/0001_initial.py

@@ -28,5 +28,15 @@ class Migration(migrations.Migration):
             options={
                 'abstract': False,
             }
+        ),
+        migrations.CreateModel(
+            name='TestConfiguredModel',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('hll_field', HllField(log2m=13, regwidth=2, expthresh=1, sparseon=0)),
+            ],
+            options={
+                'abstract': False,
+            }
         )
     ]

tests/models.py

@@ -11,3 +11,7 @@ class TestModel(models.Model):
     hll_field = HllField()
     fk = models.ForeignKey(FKModel, null=True, blank=True, on_delete=models.CASCADE)
 
+
+class TestConfiguredModel(models.Model):
+    hll_field = HllField(log2m=13, regwidth=2, expthresh=1, sparseon=0)
+

tests/test_hll_field.py

@@ -12,7 +12,7 @@
 from django_pg_hll.bulk_update import HllConcatFunction
 
 from django_pg_hll.compatibility import django_pg_bulk_update_available
-from tests.models import TestModel, FKModel
+from tests.models import TestConfiguredModel, TestModel, FKModel
 
 
 class HllFieldTest(TestCase):
@@ -40,6 +40,14 @@ def test_combine_auto_parse(self):
     def test_create(self):
         TestModel.objects.create(hll_field=HllEmpty())
 
+    def test_create_custom_params(self):
+        with connection.cursor() as cursor:
+            cursor.execute('select hll_set_defaults(13,2,1,0);')
+            try:
+                TestConfiguredModel.objects.create(hll_field=HllEmpty())
+            finally:
+                cursor.execute('select hll_set_defaults(11,5,-1,1);')
+
     def test_migration(self):
         query = "SELECT hll_cardinality(hll_field) FROM tests_testmodel;"
         self.cursor.execute(query)