7 files changed, 125 insertions, 14 deletions

diff --git a/src/mailman/database/alembic/script.py.mako b/src/mailman/database/alembic/script.py.mako
index 95702017e..acc126c54 100644
--- a/src/mailman/database/alembic/script.py.mako
+++ b/src/mailman/database/alembic/script.py.mako
@@ -12,6 +12,7 @@ down_revision = ${repr(down_revision)}
 
 from alembic import op
 import sqlalchemy as sa
+from mailman.database.utilities import is_sqlite, exists_in_db
 ${imports if imports else ""}
 
 def upgrade():
diff --git a/src/mailman/database/alembic/versions/16c2b25c7b_list_subscription_policy.py b/src/mailman/database/alembic/versions/16c2b25c7b_list_subscription_policy.py
index 8534f4b73..1d21735c6 100644
--- a/src/mailman/database/alembic/versions/16c2b25c7b_list_subscription_policy.py
+++ b/src/mailman/database/alembic/versions/16c2b25c7b_list_subscription_policy.py
@@ -14,14 +14,17 @@ from alembic import op
 import sqlalchemy as sa
 
 from mailman.database.types import Enum
+from mailman.database.utilities import is_sqlite, exists_in_db
 from mailman.interfaces.mailinglist import SubscriptionPolicy
 
 
 def upgrade():
 
     ### Update the schema
-    op.add_column('mailinglist', sa.Column(
-        'subscription_policy', Enum(SubscriptionPolicy), nullable=True))
+    if not exists_in_db(op.get_bind(), 'mailinglist', 'subscription_policy'):
+        # SQL may not have removed it when downgrading.
+        op.add_column('mailinglist', sa.Column(
+            'subscription_policy', Enum(SubscriptionPolicy), nullable=True))
 
     ### Now migrate the data
     # don't import the table definition from the models, it may break this
@@ -36,6 +39,6 @@ def upgrade():
 
 
 def downgrade():
-    if op.get_bind().dialect.name != 'sqlite':
+    if not is_sqlite(op.get_bind()):
         # SQLite does not support dropping columns.
         op.drop_column('mailinglist', 'subscription_policy')
diff --git a/src/mailman/database/alembic/versions/33e1f5f6fa8_.py b/src/mailman/database/alembic/versions/33e1f5f6fa8_.py
index 14a7a2b74..45d5929d9 100644
--- a/src/mailman/database/alembic/versions/33e1f5f6fa8_.py
+++ b/src/mailman/database/alembic/versions/33e1f5f6fa8_.py
@@ -33,6 +33,7 @@ __all__ = [
 
 from alembic import op
 import sqlalchemy as sa
+from mailman.database.utilities import is_sqlite
 
 
 # revision identifiers, used by Alembic.
@@ -41,7 +42,7 @@ down_revision = '51b7f92bd06c'
 
 
 def upgrade():
-    if op.get_bind().dialect.name != 'sqlite':
+    if not is_sqlite(op.get_bind()):
         # SQLite does not support altering columns.
         op.alter_column('message', 'message_id_hash', type_=sa.Unicode)
         op.alter_column('message', 'path', type_=sa.Unicode)
@@ -51,7 +52,7 @@ def upgrade():
 
 
 def downgrade():
-    if op.get_bind().dialect.name != 'sqlite':
+    if not is_sqlite(op.get_bind()):
         # SQLite does not support altering columns.
         op.alter_column('message', 'message_id_hash', type_=sa.LargeBinary)
         op.alter_column('message', 'path', type_=sa.LargeBinary)
diff --git a/src/mailman/database/alembic/versions/46e92facee7_add_serverowner_domainowner.py b/src/mailman/database/alembic/versions/46e92facee7_add_serverowner_domainowner.py
index fc489cae5..826961d73 100644
--- a/src/mailman/database/alembic/versions/46e92facee7_add_serverowner_domainowner.py
+++ b/src/mailman/database/alembic/versions/46e92facee7_add_serverowner_domainowner.py
@@ -29,6 +29,7 @@ down_revision = '33e1f5f6fa8'
 
 from alembic import op
 import sqlalchemy as sa
+from mailman.database.utilities import is_sqlite, exists_in_db
 
 
 def upgrade():
@@ -40,16 +41,20 @@ def upgrade():
         sa.ForeignKeyConstraint(['user_id'], ['user.id'], ),
         sa.PrimaryKeyConstraint('user_id', 'domain_id')
         )
-    op.add_column(
-        'user',
-        sa.Column('is_server_owner', sa.Boolean(), nullable=True))
-    if op.get_bind().dialect.name != 'sqlite':
+    if not exists_in_db(op.get_bind(), 'user', 'is_server_owner'):
+        # SQL may not have removed it when downgrading.
+        op.add_column(
+            'user',
+            sa.Column('is_server_owner', sa.Boolean(), nullable=True))
+    if not is_sqlite(op.get_bind()):
         op.drop_column('domain', 'contact_address')
 
 
 def downgrade():
-    if op.get_bind().dialect.name != 'sqlite':
+    if not is_sqlite(op.get_bind()):
         op.drop_column('user', 'is_server_owner')
+    if not exists_in_db(op.get_bind(), 'domain', 'contact_address'):
+        # SQLite may not have removed it.
         op.add_column(
             'domain',
             sa.Column('contact_address', sa.VARCHAR(), nullable=True))
diff --git a/src/mailman/database/alembic/versions/51b7f92bd06c_initial.py b/src/mailman/database/alembic/versions/51b7f92bd06c_initial.py
index 763554b67..ff55e5174 100644
--- a/src/mailman/database/alembic/versions/51b7f92bd06c_initial.py
+++ b/src/mailman/database/alembic/versions/51b7f92bd06c_initial.py
@@ -37,6 +37,7 @@ __all__ = [
 
 from alembic import op
 import sqlalchemy as sa
+from mailman.database.utilities import is_sqlite, exists_in_db
 
 
 # Revision identifiers, used by Alembic.
@@ -46,7 +47,7 @@ down_revision = None
 
 def upgrade():
     op.drop_table('version')
-    if op.get_bind().dialect.name != 'sqlite':
+    if not is_sqlite(op.get_bind()):
         # SQLite does not support dropping columns.
         op.drop_column('mailinglist', 'acceptable_aliases_id')
     op.create_index(op.f('ix_user__user_id'), 'user',
@@ -58,6 +59,7 @@ def downgrade():
     op.create_table('version')
     op.create_index('ix_user_user_id', 'user', ['_user_id'], unique=False)
     op.drop_index(op.f('ix_user__user_id'), table_name='user')
-    op.add_column(
-        'mailinglist',
-        sa.Column('acceptable_aliases_id', sa.INTEGER(), nullable=True))
+    if not exists_in_db(op.get_bind(), 'mailinglist', 'acceptable_aliases_id'):
+        op.add_column(
+            'mailinglist',
+            sa.Column('acceptable_aliases_id', sa.INTEGER(), nullable=True))
diff --git a/src/mailman/database/tests/test_migrations.py b/src/mailman/database/tests/test_migrations.py
new file mode 100644
index 000000000..201fd618a
--- /dev/null
+++ b/src/mailman/database/tests/test_migrations.py
@@ -0,0 +1,59 @@
+# Copyright (C) 2013-2015 by the Free Software Foundation, Inc.
+#
+# This file is part of GNU Mailman.
+#
+# GNU Mailman is free software: you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free
+# Software Foundation, either version 3 of the License, or (at your option)
+# any later version.
+#
+# GNU Mailman is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+# more details.
+#
+# You should have received a copy of the GNU General Public License along with
+# GNU Mailman.  If not, see <http://www.gnu.org/licenses/>.
+
+"""Test database schema migrations with Alembic"""
+
+__all__ = [
+    'TestMigrations',
+    ]
+
+
+import unittest
+import alembic.command
+
+from mailman.config import config
+from mailman.database.alembic import alembic_cfg
+from mailman.database.model import Model
+from mailman.testing.layers import ConfigLayer
+import sqlalchemy as sa
+
+
+
+class TestMigrations(unittest.TestCase):
+
+    layer = ConfigLayer
+
+    def setUp(self):
+        alembic.command.stamp(alembic_cfg, 'head')
+
+    def tearDown(self):
+        # Drop and restore a virgin database.
+        md = sa.MetaData()
+        md.reflect(bind=config.db.engine)
+        for table in md.sorted_tables:
+            table.drop(config.db.engine)
+        Model.metadata.create_all(config.db.engine)
+
+    def test_all_migrations(self):
+        script_dir = alembic.script.ScriptDirectory.from_config(alembic_cfg)
+        revisions = [sc.revision for sc in
+                     script_dir.walk_revisions("base", "heads")]
+        for revision in revisions:
+            alembic.command.downgrade(alembic_cfg, revision)
+        revisions.reverse()
+        for revision in revisions:
+            alembic.command.upgrade(alembic_cfg, revision)
diff --git a/src/mailman/database/utilities.py b/src/mailman/database/utilities.py
new file mode 100644
index 000000000..0db4848ca
--- /dev/null
+++ b/src/mailman/database/utilities.py
@@ -0,0 +1,40 @@
+# Copyright (C) 2006-2015 by the Free Software Foundation, Inc.
+#
+# This file is part of GNU Mailman.
+#
+# GNU Mailman is free software: you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free
+# Software Foundation, either version 3 of the License, or (at your option)
+# any later version.
+#
+# GNU Mailman is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+# more details.
+#
+# You should have received a copy of the GNU General Public License along with
+# GNU Mailman.  If not, see <http://www.gnu.org/licenses/>.
+
+"""Common database utilities."""
+
+__all__ = [
+    'exists_in_db',
+    ]
+
+import sqlalchemy as sa
+
+
+def is_sqlite(bind):
+    return bind.dialect.name == 'sqlite'
+
+
+def exists_in_db(bind, tablename, columnname=None):
+    md = sa.MetaData()
+    md.reflect(bind=bind)
+    if columnname is None:
+        return tablename in md.tables
+    else:
+        return (
+            tablename in md.tables and
+            columnname in [c.name for c in md.tables[tablename].columns]
+            )