Merge "Break optimize_db_test_loader into package and module level"

3 files changed, 166 insertions, 39 deletions

diff --git a/oslo_db/sqlalchemy/test_base.py b/oslo_db/sqlalchemy/test_base.py
index bda0d91..ab7dea2 100644
--- a/oslo_db/sqlalchemy/test_base.py
+++ b/oslo_db/sqlalchemy/test_base.py
@@ -14,9 +14,9 @@
 # under the License.
 
 import debtcollector
+import debtcollector.moves
 import fixtures
 import testresources
-import testscenarios
 
 try:
     from oslotest import base as test_base
@@ -25,8 +25,6 @@ except ImportError:
                     ' test-requirements')
 
 
-import os
-
 from oslo_utils import reflection
 import six
 
@@ -34,6 +32,7 @@ from oslo_db import exception
 from oslo_db.sqlalchemy import enginefacade
 from oslo_db.sqlalchemy import provision
 from oslo_db.sqlalchemy import session
+from oslo_db.sqlalchemy.test_fixtures import optimize_package_test_loader
 
 
 @debtcollector.removals.removed_class("DbFixture")
@@ -245,39 +244,5 @@ class PostgreSQLOpportunisticTestCase(OpportunisticTestCase):
     FIXTURE = PostgreSQLOpportunisticFixture
 
 
-def optimize_db_test_loader(file_):
-    """Package level load_tests() function.
-
-    Will apply an optimizing test suite to all sub-tests, which groups DB
-    tests and other resources appropriately.
-
-    Place this in an __init__.py package file within the root of the test
-    suite, at the level where testresources loads it as a package::
-
-        from oslo_db.sqlalchemy import test_base
-
-        load_tests = test_base.optimize_db_test_loader(__file__)
-
-    Alternatively, the directive can be placed into a test module directly.
-
-    """
-
-    this_dir = os.path.dirname(file_)
-
-    def load_tests(loader, found_tests, pattern):
-        # pattern is None if the directive is placed within
-        # a test module directly, as well as within certain test
-        # discovery patterns
-
-        if pattern is not None:
-            pkg_tests = loader.discover(start_dir=this_dir, pattern=pattern)
-
-        result = testresources.OptimisingTestSuite()
-        found_tests = testscenarios.load_tests_apply_scenarios(
-            loader, found_tests, pattern)
-        result.addTest(found_tests)
-
-        if pattern is not None:
-            result.addTest(pkg_tests)
-        return result
-    return load_tests
+optimize_db_test_loader = debtcollector.moves.moved_function(
+    optimize_package_test_loader, "optimize_db_test_loader", __name__)
diff --git a/oslo_db/sqlalchemy/test_fixtures.py b/oslo_db/sqlalchemy/test_fixtures.py
index 8b35ac3..fd954b3 100644
--- a/oslo_db/sqlalchemy/test_fixtures.py
+++ b/oslo_db/sqlalchemy/test_fixtures.py
@@ -15,7 +15,9 @@
 
 import fixtures
 import logging
+import os
 import testresources
+import testscenarios
 
 from oslo_db import exception
 from oslo_db.sqlalchemy import enginefacade
@@ -544,3 +546,79 @@ class MySQLOpportunisticFixture(OpportunisticDbFixture):
 
 class PostgresqlOpportunisticFixture(OpportunisticDbFixture):
     DRIVER = 'postgresql'
+
+
+def optimize_package_test_loader(file_):
+    """Organize package-level tests into a testresources.OptimizingTestSuite.
+
+    This function provides a unittest-compatible load_tests hook
+    for a given package; for per-module, use the
+    :func:`.optimize_module_test_loader` function.
+
+    When a unitest or subunit style
+    test runner is used, the function will be called in order to
+    return a TestSuite containing the tests to run; this function
+    ensures that this suite is an OptimisingTestSuite, which will organize
+    the production of test resources across groups of tests at once.
+
+    The function is invoked as::
+
+        from oslo_db.sqlalchemy import test_base
+
+        load_tests = test_base.optimize_package_test_loader(__file__)
+
+    The loader *must* be present in the package level __init__.py.
+
+    The function also applies testscenarios expansion to all  test collections.
+    This so that an existing test suite that already needs to build
+    TestScenarios from a load_tests call can still have this take place when
+    replaced with this function.
+
+    """
+
+    this_dir = os.path.dirname(file_)
+
+    def load_tests(loader, found_tests, pattern):
+        result = testresources.OptimisingTestSuite()
+        result.addTests(found_tests)
+        pkg_tests = loader.discover(start_dir=this_dir, pattern=pattern)
+        result.addTests(testscenarios.generate_scenarios(pkg_tests))
+
+        return result
+    return load_tests
+
+
+def optimize_module_test_loader():
+    """Organize module-level tests into a testresources.OptimizingTestSuite.
+
+    This function provides a unittest-compatible load_tests hook
+    for a given module; for per-package, use the
+    :func:`.optimize_package_test_loader` function.
+
+    When a unitest or subunit style
+    test runner is used, the function will be called in order to
+    return a TestSuite containing the tests to run; this function
+    ensures that this suite is an OptimisingTestSuite, which will organize
+    the production of test resources across groups of tests at once.
+
+    The function is invoked as::
+
+        from oslo_db.sqlalchemy import test_base
+
+        load_tests = test_base.optimize_module_test_loader()
+
+    The loader *must* be present in an individual module, and *not* the
+    package level __init__.py.
+
+    The function also applies testscenarios expansion to all  test collections.
+    This so that an existing test suite that already needs to build
+    TestScenarios from a load_tests call can still have this take place when
+    replaced with this function.
+
+    """
+
+    def load_tests(loader, found_tests, pattern):
+        result = testresources.OptimisingTestSuite()
+        result.addTests(testscenarios.generate_scenarios(found_tests))
+        return result
+    return load_tests
diff --git a/oslo_db/tests/sqlalchemy/test_fixtures.py b/oslo_db/tests/sqlalchemy/test_fixtures.py
index 44fed1e..f256d30 100644
--- a/oslo_db/tests/sqlalchemy/test_fixtures.py
+++ b/oslo_db/tests/sqlalchemy/test_fixtures.py
@@ -11,7 +11,10 @@
 #    under the License.
 
 import mock
+import os
 import testresources
+import testscenarios
+import unittest
 
 from oslo_db.sqlalchemy import enginefacade
 from oslo_db.sqlalchemy import provision
@@ -19,6 +22,8 @@ from oslo_db.sqlalchemy import test_base as legacy_test_base
 from oslo_db.sqlalchemy import test_fixtures
 from oslotest import base as oslo_test_base
 
+start_dir = os.path.dirname(__file__)
+
 
 class BackendSkipTest(oslo_test_base.BaseTestCase):
 
@@ -212,3 +217,82 @@ class LegacyBaseClassTest(oslo_test_base.BaseTestCase):
 
             db_resource = dict(st.resources)['db']
             self.assertTrue(db_resource.provision_new_database)
+
+
+class TestLoadHook(unittest.TestCase):
+    """Test the 'load_tests' hook supplied by test_base.
+
+    The purpose of this loader is to organize tests into an
+    OptimisingTestSuite using the standard unittest load_tests hook.
+    The hook needs to detect if it is being invoked at the module
+    level or at the package level.  It has to behave completely differently
+    in these two cases.
+
+    """
+
+    def test_module_level(self):
+        load_tests = test_fixtures.optimize_module_test_loader()
+
+        loader = unittest.TestLoader()
+
+        found_tests = loader.discover(start_dir, pattern="test_fixtures.py")
+        new_loader = load_tests(loader, found_tests, "test_fixtures.py")
+
+        self.assertTrue(
+            isinstance(new_loader, testresources.OptimisingTestSuite)
+        )
+
+        actual_tests = unittest.TestSuite(
+            testscenarios.generate_scenarios(found_tests)
+        )
+
+        self.assertEqual(
+            new_loader.countTestCases(), actual_tests.countTestCases()
+        )
+
+    def test_package_level(self):
+        self._test_package_level(test_fixtures.optimize_package_test_loader)
+
+    def test_package_level_legacy(self):
+        self._test_package_level(legacy_test_base.optimize_db_test_loader)
+
+    def _test_package_level(self, fn):
+        load_tests = fn(
+            os.path.join(start_dir, "__init__.py"))
+
+        loader = unittest.TestLoader()
+
+        new_loader = load_tests(
+            loader, unittest.suite.TestSuite(), "test_fixtures.py")
+
+        self.assertTrue(
+            isinstance(new_loader, testresources.OptimisingTestSuite)
+        )
+
+        actual_tests = unittest.TestSuite(
+            testscenarios.generate_scenarios(
+                loader.discover(start_dir, pattern="test_fixtures.py"))
+        )
+
+        self.assertEqual(
+            new_loader.countTestCases(), actual_tests.countTestCases()
+        )
+
+
+class TestWScenarios(unittest.TestCase):
+    """a 'do nothing' test suite.
+
+    Should generate exactly four tests when testscenarios is used.
+
+    """
+
+    def test_one(self):
+        pass
+
+    def test_two(self):
+        pass
+
+    scenarios = [
+        ('scenario1', dict(scenario='scenario 1')),
+        ('scenario2', dict(scenario='scenario 2'))
+    ]