Fix case where non-AbstractContainer is base class (#444)

hdmf-dev · Oct 23, 2020 · 64c1c97 · 64c1c97
1 parent 06064be
commit 64c1c97
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Showing 2 changed files with 34 additions and 3 deletions.
diff --git a/src/hdmf/container.py b/src/hdmf/container.py
@@ -119,15 +119,20 @@ def __gather_fields(cls, name, bases, classdict):
 
         # check whether this class overrides __fields__
         if len(bases):
-            base_fields = bases[-1]._get_fields()  # tuple of field names from base class
+            # find highest base class that is an AbstractContainer (parent is higher than children)
+            base_cls = None
+            for base_cls in reversed(bases):
+                if issubclass(base_cls, AbstractContainer):
+                    break
+            base_fields = base_cls._get_fields()  # tuple of field names from base class
             if base_fields is not fields:
                 # check whether new fields spec already exists in base class
                 for field_name in fields_dict:
                     if field_name in base_fields:
                         raise ValueError("Field '%s' cannot be defined in %s. It already exists on base class %s."
-                                         % (field_name, cls.__name__, bases[-1].__name__))
+                                         % (field_name, cls.__name__, base_cls.__name__))
                 # prepend field specs from base class to fields list of this class
-                all_fields_conf[0:0] = bases[-1].get_fields_conf()
+                all_fields_conf[0:0] = base_cls.get_fields_conf()
 
         # create getter and setter if attribute does not already exist
         # if 'doc' not specified in __fields__, use doc from docval of __init__

diff --git a/tests/unit/test_container.py b/tests/unit/test_container.py
@@ -378,6 +378,32 @@ class NamedFields(AbstractContainer):
             class NamedFieldsChild(NamedFields):
                 __fields__ = ({'name': 'field1', 'settable': True}, )
 
+    def test_mult_inheritance_base_mixin(self):
+        class NamedFields(AbstractContainer):
+            __fields__ = ({'name': 'field1', 'doc': 'field1 doc', 'settable': False}, )
+
+        class BlankMixin:
+            pass
+
+        class NamedFieldsChild(NamedFields, BlankMixin):
+            __fields__ = ({'name': 'field2'}, )
+
+        self.assertTupleEqual(NamedFieldsChild.__fields__, ('field1', 'field2'))
+        self.assertIs(NamedFieldsChild._get_fields(), NamedFieldsChild.__fields__)
+
+    def test_mult_inheritance_base_container(self):
+        class NamedFields(AbstractContainer):
+            __fields__ = ({'name': 'field1', 'doc': 'field1 doc', 'settable': False}, )
+
+        class BlankMixin:
+            pass
+
+        class NamedFieldsChild(BlankMixin, NamedFields):
+            __fields__ = ({'name': 'field2'}, )
+
+        self.assertTupleEqual(NamedFieldsChild.__fields__, ('field1', 'field2'))
+        self.assertIs(NamedFieldsChild._get_fields(), NamedFieldsChild.__fields__)
+
 
 class TestContainerFieldsConf(TestCase):