feat: Add new test for roundtrip downgrade isolation.

examples/test_downgrade_leaves_no_trace_failure/alembic.ini

@@ -0,0 +1,36 @@
+[alembic]
+script_location = migrations
+
+[loggers]
+keys = root,sqlalchemy,alembic
+
+[handlers]
+keys = console
+
+[formatters]
+keys = generic
+
+[logger_root]
+level = WARN
+handlers = console
+qualname =
+
+[logger_sqlalchemy]
+level = WARN
+handlers =
+qualname = sqlalchemy.engine
+
+[logger_alembic]
+level = INFO
+handlers =
+qualname = alembic
+
+[handler_console]
+class = StreamHandler
+args = (sys.stderr,)
+level = NOTSET
+formatter = generic
+
+[formatter_generic]
+format = %(levelname)-5.5s [%(name)s] %(message)s
+datefmt = %H:%M:%S

examples/test_downgrade_leaves_no_trace_failure/conftest.py

@@ -0,0 +1,3 @@
+from pytest_mock_resources import create_postgres_fixture
+
+alembic_engine = create_postgres_fixture()

examples/test_downgrade_leaves_no_trace_failure/migrations/env.py

@@ -0,0 +1,25 @@
+from logging.config import fileConfig
+
+from alembic import context
+from sqlalchemy import engine_from_config, pool
+
+from models import Base
+
+fileConfig(context.config.config_file_name)
+target_metadata = Base.metadata
+
+
+connectable = context.config.attributes.get("connection", None)
+
+if connectable is None:
+    connectable = engine_from_config(
+        context.config.get_section(context.config.config_ini_section),
+        prefix="sqlalchemy.",
+        poolclass=pool.NullPool,
+    )
+
+with connectable.connect() as connection:
+    context.configure(connection=connection, target_metadata=target_metadata)
+
+    with context.begin_transaction():
+        context.run_migrations()

examples/test_downgrade_leaves_no_trace_failure/migrations/script.py.mako

@@ -0,0 +1,24 @@
+"""${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision | comma,n}
+Create Date: ${create_date}
+
+"""
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
+# revision identifiers, used by Alembic.
+revision = ${repr(up_revision)}
+down_revision = ${repr(down_revision)}
+branch_labels = ${repr(branch_labels)}
+depends_on = ${repr(depends_on)}
+
+
+def upgrade():
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade():
+    ${downgrades if downgrades else "pass"}

examples/test_downgrade_leaves_no_trace_failure/migrations/versions/aaaaaaaaaaaa_create_foo.py

@@ -0,0 +1,19 @@
+from alembic import op
+import sqlalchemy as sa
+
+revision = "aaaaaaaaaaaa"
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    op.create_table(
+        "foo",
+        sa.Column("id", sa.Integer(), autoincrement=True, nullable=False),
+        sa.PrimaryKeyConstraint("id"),
+    )
+
+
+def downgrade():
+    op.rename_table('foo', 'bar')

examples/test_downgrade_leaves_no_trace_failure/models.py

@@ -0,0 +1,11 @@
+import sqlalchemy
+from sqlalchemy import Column, types
+from sqlalchemy.ext.declarative import declarative_base
+
+Base = declarative_base()
+
+
+class CreatedAt(Base):
+    __tablename__ = "foo"
+
+    id = Column(types.Integer(), autoincrement=True, primary_key=True)

examples/test_downgrade_leaves_no_trace_failure/setup.cfg

@@ -0,0 +1,2 @@
+[tool:pytest]
+pytest_alembic_include_experimental = downgrade_leaves_no_trace

examples/test_downgrade_leaves_no_trace_success/alembic.ini

@@ -0,0 +1,36 @@
+[alembic]
+script_location = migrations
+
+[loggers]
+keys = root,sqlalchemy,alembic
+
+[handlers]
+keys = console
+
+[formatters]
+keys = generic
+
+[logger_root]
+level = WARN
+handlers = console
+qualname =
+
+[logger_sqlalchemy]
+level = WARN
+handlers =
+qualname = sqlalchemy.engine
+
+[logger_alembic]
+level = INFO
+handlers =
+qualname = alembic
+
+[handler_console]
+class = StreamHandler
+args = (sys.stderr,)
+level = NOTSET
+formatter = generic
+
+[formatter_generic]
+format = %(levelname)-5.5s [%(name)s] %(message)s
+datefmt = %H:%M:%S

examples/test_downgrade_leaves_no_trace_success/conftest.py

@@ -0,0 +1,3 @@
+from pytest_mock_resources import create_postgres_fixture
+
+alembic_engine = create_postgres_fixture()

examples/test_downgrade_leaves_no_trace_success/migrations/env.py

@@ -0,0 +1,25 @@
+from logging.config import fileConfig
+
+from alembic import context
+from sqlalchemy import engine_from_config, pool
+
+from models import Base
+
+fileConfig(context.config.config_file_name)
+target_metadata = Base.metadata
+
+
+connectable = context.config.attributes.get("connection", None)
+
+if connectable is None:
+    connectable = engine_from_config(
+        context.config.get_section(context.config.config_ini_section),
+        prefix="sqlalchemy.",
+        poolclass=pool.NullPool,
+    )
+
+with connectable.connect() as connection:
+    context.configure(connection=connection, target_metadata=target_metadata)
+
+    with context.begin_transaction():
+        context.run_migrations()

examples/test_downgrade_leaves_no_trace_success/migrations/script.py.mako

@@ -0,0 +1,24 @@
+"""${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision | comma,n}
+Create Date: ${create_date}
+
+"""
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
+# revision identifiers, used by Alembic.
+revision = ${repr(up_revision)}
+down_revision = ${repr(down_revision)}
+branch_labels = ${repr(branch_labels)}
+depends_on = ${repr(depends_on)}
+
+
+def upgrade():
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade():
+    ${downgrades if downgrades else "pass"}

examples/test_downgrade_leaves_no_trace_success/migrations/versions/aaaaaaaaaaaa_create_foo.py

@@ -0,0 +1,19 @@
+from alembic import op
+import sqlalchemy as sa
+
+revision = "aaaaaaaaaaaa"
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    op.create_table(
+        "foo",
+        sa.Column("id", sa.Integer(), autoincrement=True, nullable=False),
+        sa.PrimaryKeyConstraint("id"),
+    )
+
+
+def downgrade():
+    op.drop_table('foo')

examples/test_downgrade_leaves_no_trace_success/models.py

@@ -0,0 +1,11 @@
+import sqlalchemy
+from sqlalchemy import Column, types
+from sqlalchemy.ext.declarative import declarative_base
+
+Base = declarative_base()
+
+
+class CreatedAt(Base):
+    __tablename__ = "foo"
+
+    id = Column(types.Integer(), autoincrement=True, primary_key=True)

examples/test_downgrade_leaves_no_trace_success/setup.cfg

@@ -0,0 +1,2 @@
+[tool:pytest]
+pytest_alembic_include_experimental = downgrade_leaves_no_trace

src/pytest_alembic/tests/experimental/__init__.py

@@ -2,3 +2,6 @@
 from pytest_alembic.tests.experimental.all_models_register_on_metadata import (
     test_all_models_register_on_metadata,
 )
+from pytest_alembic.tests.experimental.downgrade_leaves_no_trace import (
+    test_downgrade_leaves_no_trace,
+)

src/pytest_alembic/tests/experimental/downgrade_leaves_no_trace.py

@@ -0,0 +1,41 @@
+from typing import List, Optional, Set, Tuple
+
+from sqlalchemy import MetaData
+
+from pytest_alembic.plugin.error import AlembicTestFailure
+from pytest_alembic.runner import MigrationContext
+
+try:
+    from sqlalchemy.ext.declarative import DeclarativeMeta
+except ImportError:  # pragma: no cover
+    from sqlalchemy.declarative import DeclarativeMeta
+
+
+def test_downgrade_leaves_no_trace(alembic_runner: MigrationContext, alembic_engine):
+    """Assert that all tables defined on your `MetaData`, are imported in the `env.py`.
+
+    """
+    original_metadata = MetaData()
+    original_metadata.reflect(alembic_engine)
+
+    alembic_runner.migrate_up_one()
+
+    upgrade_metadata = MetaData()
+    upgrade_metadata.reflect(alembic_engine)
+
+    alembic_runner.migrate_down_one()
+
+    downgrade_metadata = MetaData()
+    downgrade_metadata.reflect(alembic_engine)
+
+    # old_tables = {k: v for k, v in old_metadata.tables.items()}
+    # new_tables = {k: v for k, v in new_metadata.tables.items() if k != 'alembic_version'}
+
+    import pdb; pdb.set_trace()
+    if new_tables:
+        tables = ', '.join(new_tables.keys())
+        raise AlembicTestFailure(
+            f"{new_tables}"
+        )
+
+    raise

tests/test_runner.py

@@ -155,3 +155,21 @@ def test_consistency_doesnt_roundtrip(pytester):
     assert_failed_test_has_content(
         result, test="test_up_down_consistency", content="after performing a roundtrip"
     )
+
+def test_downgrade_leaves_no_trace_success(pytester):
+    """Assert the all-models-register test is collected when included through automatic test insertion.
+
+    I.e. through use of pytest_alembic_include_experimental, rather than a manually
+    written test.
+    """
+    result = run_pytest(pytester, passed=5)
+    assert_has_test(result, "test_downgrade_leaves_no_trace")
+
+
+def test_downgrade_leaves_no_trace_failure(pytester):
+    """Assert the all-models-register test is collected when included through automatic test insertion.
+    """
+    result = run_pytest(pytester, success=False, passed=0, failed=1, test_alembic=False)
+    assert_failed_test_has_content(
+        result, test="test_downgrade_leaves_no_trace", content="after performing a roundtrip"
+    )