Fix list-value coercion regression.

Fixes #2070
Refs #2046

peewee.py

@@ -4452,7 +4452,7 @@ def python_value(self, value):
         return value if value is None else self.adapt(value)
 
     def to_value(self, value):
-        return Value(value, self.db_value, self.unpack)
+        return Value(value, self.db_value, unpack=False)
 
     def get_sort_key(self, ctx):
         return self._sort_key

playhouse/postgres_ext.py

@@ -154,7 +154,6 @@ def __init__(self, *args, **kwargs):
 
 class ArrayField(IndexedFieldMixin, Field):
     passthrough = True
-    unpack = False
 
     def __init__(self, field_class=IntegerField, field_kwargs=None,
                  dimensions=1, convert_values=False, *args, **kwargs):
@@ -238,7 +237,6 @@ class DateTimeTZField(DateTimeField):
 
 class HStoreField(IndexedFieldMixin, Field):
     field_type = 'HSTORE'
-    unpack = False
     __hash__ = Field.__hash__
 
     def __getitem__(self, key):
@@ -284,7 +282,6 @@ def contains_any(self, *keys):
 
 class JSONField(Field):
     field_type = 'JSON'
-    unpack = False
     _json_datatype = 'json'
 
     def __init__(self, dumps=None, *args, **kwargs):

tests/regressions.py

@@ -1,4 +1,5 @@
 import datetime
+import json
 
 from peewee import *
 from playhouse.hybrid import *
@@ -1067,3 +1068,43 @@ def assertQ(q):
              .filter(page__site__url='s1')
              .order_by(PageItem.content))
         assertQ(q)
+
+
+class JsonField(TextField):
+    def db_value(self, value):
+        return json.dumps(value) if value is not None else None
+    def python_value(self, value):
+        if value is not None:
+            return json.loads(value)
+
+class JM(TestModel):
+    key = TextField()
+    data = JsonField()
+
+
+class TestListValueConversion(ModelTestCase):
+    requires = [JM]
+
+    def test_list_value_conversion(self):
+        jm = JM.create(key='k1', data=['i0', 'i1'])
+        jm.key = 'k1-x'
+        jm.save()
+
+        jm_db = JM.get(JM.key == 'k1-x')
+        self.assertEqual(jm_db.data, ['i0', 'i1'])
+
+        JM.update(data=['i1', 'i2']).execute()
+        jm_db = JM.get(JM.key == 'k1-x')
+        self.assertEqual(jm_db.data, ['i1', 'i2'])
+
+        jm2 = JM.create(key='k2', data=['i3', 'i4'])
+
+        jm_db.data = ['i1', 'i2', 'i3']
+        jm2.data = ['i4', 'i5']
+
+        JM.bulk_update([jm_db, jm2], fields=[JM.key, JM.data])
+
+        jm = JM.get(JM.key == 'k1-x')
+        self.assertEqual(jm.data, ['i1', 'i2', 'i3'])
+        jm2 = JM.get(JM.key == 'k2')
+        self.assertEqual(jm2.data, ['i4', 'i5'])