Fixed #20550 -- Added ability to preserve test db between runs

django/contrib/gis/db/backends/postgis/creation.py

@@ -82,8 +82,10 @@ class PostGISCreation(DatabaseCreation):
                 self.connection.ops.quote_name(self.template_postgis),)
         return ''
 
-    def _create_test_db(self, verbosity, autoclobber):
-        test_database_name = super(PostGISCreation, self)._create_test_db(verbosity, autoclobber)
+    def _create_test_db(self, verbosity, autoclobber, keepdb=False):
+        test_database_name = super(PostGISCreation, self)._create_test_db(verbosity, autoclobber, keepdb)
+        if keepdb:
+            return test_database_name
         if self.template_postgis is None:
             # Connect to the test database in order to create the postgis extension
             self.connection.close()

django/contrib/gis/db/backends/spatialite/creation.py

@@ -7,7 +7,7 @@ from django.db.backends.sqlite3.creation import DatabaseCreation
 
 class SpatiaLiteCreation(DatabaseCreation):
 
-    def create_test_db(self, verbosity=1, autoclobber=False):
+    def create_test_db(self, verbosity=1, autoclobber=False, keepdb=False):
         """
         Creates a test database, prompting the user for confirmation if the
         database already exists. Returns the name of the test database created.
@@ -22,11 +22,15 @@ class SpatiaLiteCreation(DatabaseCreation):
 
         if verbosity >= 1:
             test_db_repr = ''
+            action = 'Creating'
             if verbosity >= 2:
                 test_db_repr = " ('%s')" % test_database_name
-            print("Creating test database for alias '%s'%s..." % (self.connection.alias, test_db_repr))
+            if keepdb:
+                action = 'Using existing'
+            print("%s test database for alias '%s'%s..." % (
+                action, self.connection.alias, test_db_repr))
 
-        self._create_test_db(verbosity, autoclobber)
+        self._create_test_db(verbosity, autoclobber, keepdb)
 
         self.connection.close()
         self.connection.settings_dict["NAME"] = test_database_name

django/db/backends/creation.py

@@ -332,7 +332,7 @@ class BaseDatabaseCreation(object):
             ";",
         ]
 
-    def create_test_db(self, verbosity=1, autoclobber=False):
+    def create_test_db(self, verbosity=1, autoclobber=False, keepdb=False):
         """
         Creates a test database, prompting the user for confirmation if the
         database already exists. Returns the name of the test database created.
@@ -344,12 +344,21 @@ class BaseDatabaseCreation(object):
 
         if verbosity >= 1:
             test_db_repr = ''
+            action = 'Creating'
             if verbosity >= 2:
                 test_db_repr = " ('%s')" % test_database_name
-            print("Creating test database for alias '%s'%s..." % (
-                self.connection.alias, test_db_repr))
+            if keepdb:
+                action = "Using existing"
+
+            print("%s test database for alias '%s'%s..." % (
+                action, self.connection.alias, test_db_repr))
 
-        self._create_test_db(verbosity, autoclobber)
+        # We could skip this call if keepdb is True, but we instead
+        # give it the keepdb param. This is to handle the case
+        # where the test DB doesn't exist, in which case we need to
+        # create it, then just not destroy it. If we instead skip
+        # this, we will get an exception.
+        self._create_test_db(verbosity, autoclobber, keepdb)
 
         self.connection.close()
         settings.DATABASES[self.connection.alias]["NAME"] = test_database_name
@@ -393,7 +402,7 @@ class BaseDatabaseCreation(object):
             return self.connection.settings_dict['TEST']['NAME']
         return TEST_DATABASE_PREFIX + self.connection.settings_dict['NAME']
 
-    def _create_test_db(self, verbosity, autoclobber):
+    def _create_test_db(self, verbosity, autoclobber, keepdb=False):
         """
         Internal implementation - creates the test db tables.
         """
@@ -409,6 +418,11 @@ class BaseDatabaseCreation(object):
                 cursor.execute(
                     "CREATE DATABASE %s %s" % (qn(test_database_name), suffix))
             except Exception as e:
+                # if we want to keep the db, then no need to do any of the below,
+                # just return and skip it all.
+                if keepdb:
+                    return test_database_name
+
                 sys.stderr.write(
                     "Got an error creating the test database: %s\n" % e)
                 if not autoclobber:

django/db/backends/oracle/creation.py

@@ -56,7 +56,7 @@ class DatabaseCreation(BaseDatabaseCreation):
     def __init__(self, connection):
         super(DatabaseCreation, self).__init__(connection)
 
-    def _create_test_db(self, verbosity=1, autoclobber=False):
+    def _create_test_db(self, verbosity=1, autoclobber=False, keepdb=False):
         TEST_NAME = self._test_database_name()
         TEST_USER = self._test_database_user()
         TEST_PASSWD = self._test_database_passwd()
@@ -76,6 +76,10 @@ class DatabaseCreation(BaseDatabaseCreation):
             try:
                 self._execute_test_db_creation(cursor, parameters, verbosity)
             except Exception as e:
+                # if we want to keep the db, then no need to do any of the below,
+                # just return and skip it all.
+                if keepdb:
+                    return
                 sys.stderr.write("Got an error creating the test database: %s\n" % e)
                 if not autoclobber:
                     confirm = input("It appears the test database, %s, already exists. Type 'yes' to delete it, or 'no' to cancel: " % TEST_NAME)

django/db/backends/sqlite3/creation.py

@@ -52,8 +52,10 @@ class DatabaseCreation(BaseDatabaseCreation):
             return test_database_name
         return ':memory:'
 
-    def _create_test_db(self, verbosity, autoclobber):
+    def _create_test_db(self, verbosity, autoclobber, keepdb=False):
         test_database_name = self._get_test_db_name()
+        if keepdb:
+            return test_database_name
         if test_database_name != ':memory:':
             # Erase the old test database
             if verbosity >= 1:

django/test/runner.py

@@ -26,10 +26,13 @@ class DiscoverRunner(object):
         make_option('-p', '--pattern', action='store', dest='pattern',
             default="test*.py",
             help='The test matching pattern. Defaults to test*.py.'),
+        make_option('-k', '--keepdb', action='store_true', dest='keepdb',
+            default=False,
+            help='Preserve the test DB between runs. Defaults to False'),
     )
 
     def __init__(self, pattern=None, top_level=None,
-                 verbosity=1, interactive=True, failfast=False,
+                 verbosity=1, interactive=True, failfast=False, keepdb=False,
                  **kwargs):
 
         self.pattern = pattern
@@ -38,6 +41,7 @@ class DiscoverRunner(object):
         self.verbosity = verbosity
         self.interactive = interactive
         self.failfast = failfast
+        self.keepdb = keepdb
 
     def setup_test_environment(self, **kwargs):
         setup_test_environment()
@@ -106,7 +110,7 @@ class DiscoverRunner(object):
         return reorder_suite(suite, self.reorder_by)
 
     def setup_databases(self, **kwargs):
-        return setup_databases(self.verbosity, self.interactive, **kwargs)
+        return setup_databases(self.verbosity, self.interactive, self.keepdb, **kwargs)
 
     def run_suite(self, suite, **kwargs):
         return self.test_runner(
@@ -120,7 +124,7 @@ class DiscoverRunner(object):
         """
         old_names, mirrors = old_config
         for connection, old_name, destroy in old_names:
-            if destroy:
+            if destroy and not self.keepdb:
                 connection.creation.destroy_test_db(old_name, self.verbosity)
 
     def teardown_test_environment(self, **kwargs):
@@ -250,7 +254,7 @@ def partition_suite(suite, classes, bins):
                 bins[-1].addTest(test)
 
 
-def setup_databases(verbosity, interactive, **kwargs):
+def setup_databases(verbosity, interactive, keepdb=False, **kwargs):
     from django.db import connections, DEFAULT_DB_ALIAS
 
     # First pass -- work out which databases actually need to be created,
@@ -294,7 +298,7 @@ def setup_databases(verbosity, interactive, **kwargs):
             connection = connections[alias]
             if test_db_name is None:
                 test_db_name = connection.creation.create_test_db(
-                    verbosity, autoclobber=not interactive)
+                    verbosity, autoclobber=not interactive, keepdb=keepdb)
                 destroy = True
             else:
                 connection.settings_dict['NAME'] = test_db_name

docs/ref/django-admin.txt

@@ -1310,6 +1310,17 @@ The ``--liveserver`` option can be used to override the default address where
 the live server (used with :class:`~django.test.LiveServerTestCase`) is
 expected to run from. The default value is ``localhost:8081``.
 
+.. django-admin-option:: --keepdb
+
+.. versionadded:: 1.8
+
+The ``--keepdb`` option can be used to preserve the test database between test
+runs. This has the advantage of skipping both the create and destroy actions
+which greatly decreases the time to run tests, especially those in a large
+test suite. If the test database does not exist, it will be created on the first
+run and then preserved for each subsequent run. Any unapplied migrations will also
+be applied to the test database before running the test suite.
+
 testserver <fixture fixture ...>
 --------------------------------
 

docs/releases/1.8.txt

@@ -189,6 +189,9 @@ Tests
 * The new :meth:`~django.test.SimpleTestCase.assertJSONNotEqual` assertion
   allows you to test that two JSON fragments are not equal.
 
+* Added the ability to preserve the test database by adding the :djadminopt:`--keepdb`
+  flag.
+
 Validators
 ^^^^^^^^^^
 

docs/topics/testing/overview.txt

@@ -149,6 +149,14 @@ Tests that require a database (namely, model tests) will not use your "real"
 Regardless of whether the tests pass or fail, the test databases are destroyed
 when all the tests have been executed.
 
+.. versionadded:: 1.8
+
+   You can prevent the test databases from being destroyed by adding the
+   :djadminopt:`--keepdb` flag to the test command. This will preserve the test
+   database between runs. If the database does not exist, it will first
+   be created. Any migrations will also be applied in order to keep it
+   up to date.
+
 By default the test databases get their names by prepending ``test_``
 to the value of the :setting:`NAME` settings for the databases
 defined in :setting:`DATABASES`. When using the SQLite database engine

tests/test_runner/tests.py

@@ -310,7 +310,7 @@ class AliasedDatabaseTeardownTest(unittest.TestCase):
         try:
             destroyed_names = []
             DatabaseCreation.destroy_test_db = lambda self, old_database_name, verbosity=1: destroyed_names.append(old_database_name)
-            DatabaseCreation.create_test_db = lambda self, verbosity=1, autoclobber=False: self._get_test_db_name()
+            DatabaseCreation.create_test_db = lambda self, verbosity=1, autoclobber=False, keepdb=False: self._get_test_db_name()
 
             db.connections = db.ConnectionHandler({
                 'default': {