fix(#144): ensure enum-types have unique names

sqlalchemy_history/table_builder.py

@@ -2,6 +2,8 @@
 """
 import sqlalchemy as sa
 
+from sqlalchemy.sql.sqltypes import Enum
+
 
 class ColumnReflector(object):
     def __init__(self, manager, parent_table, model=None):
@@ -19,7 +21,7 @@ def reflect_column(self, column):
         """Make a copy of parent table column and some alterations to it.
 
         :param column: SQLAlchemy Column object of parent table
-
+`
         """
         # Make a copy of the column so that it does not point to wrong table.
         column_copy = column._copy()
@@ -31,6 +33,8 @@ def reflect_column(self, column):
             column_copy.autoincrement = False
         if column_copy.name == self.option("transaction_column_name"):
             column_copy.nullable = False
+        if isinstance(column_copy.type, Enum):
+            column_copy.type.name = 'history_' + column_copy.type.name
 
         if not column_copy.primary_key:
             column_copy.nullable = True

tests/builders/test_table_builder.py

@@ -93,6 +93,9 @@ class Article(self.Model):
             last_update = sa.Column(
                 sa.DateTime, default=datetime.utcnow, onupdate=datetime.utcnow, nullable=False
             )
+            enum_col = sa.Column(
+                sa.Enum('TYPE_A', 'TYPE_B', name='test_enum')
+            )
 
         self.Article = Article
 
@@ -124,3 +127,24 @@ def test_created_tables_retain_schema(self):
         table = version_class(self.Article).__table__
         assert table.schema is not None
         assert table.schema == self.Article.__table__.schema
+
+
+class TestEnumNaming(TestCase):
+    def create_models(self):
+        class Article(self.Model):
+            __tablename__ = "article"
+            __versioned__ = copy(self.options)
+
+            id = sa.Column(
+                sa.Integer, sa.Sequence(f"{__tablename__}_seq", start=1), autoincrement=True, primary_key=True
+            )
+
+            enum_col = sa.Column(
+                sa.Enum('TYPE_A', 'TYPE_B', name='test_enum')
+            )
+
+        self.Article = Article
+
+    def test_name_enums(self):
+        version_model = version_class(self.Article)
+        assert version_model.enum_col.type.name == 'history_test_enum'