[multi-db] Added first request isolation tests (testing that database settings can safely change between requests).

git-svn-id: http://code.djangoproject.com/svn/django/branches/multiple-db-support@3391 bcc190cf-cafb-0310-a4f2-bffc1f526a37

tests/othertests/request_isolation.py

@@ -0,0 +1,115 @@
+# tests that db settings can change between requests
+import copy
+import os
+from django.conf import settings
+from django.core.handlers.wsgi import WSGIHandler
+from django.db import models, model_connection_name, _default, connection
+from django.http import HttpResponse
+
+# state holder
+S = {}
+
+# models
+class MX(models.Model):
+    val = models.CharField(maxlength=10)
+    class Meta:
+        app_label = 'ri'
+
+        
+class MY(models.Model):
+    val = models.CharField(maxlength=10)
+    class Meta:
+        app_label = 'ri'
+
+
+# tests
+def test_one(path, request):
+    """Start out with settings as originally configured"""
+    assert model_connection_name(MX) == 'django_test_db_a'
+    assert MX._default_manager.db.connection.settings.DATABASE_NAME == \
+           settings.OTHER_DATABASES['django_test_db_a']['DATABASE_NAME']
+    assert model_connection_name(MY) == 'django_test_db_b'
+    assert MY._default_manager.db.connection.settings.DATABASE_NAME == \
+           settings.OTHER_DATABASES['django_test_db_b']['DATABASE_NAME'], \
+           "%s != %s" % \
+           (MY._default_manager.db.connection.settings.DATABASE_NAME,
+            settings.OTHER_DATABASES['django_test_db_b']['DATABASE_NAME'])
+
+
+def test_two(path, request):
+    """Between the first and second requests, settings change to assign
+    model MY to a different connection
+    """
+    assert model_connection_name(MX) == 'django_test_db_a'
+    assert MX._default_manager.db.connection.settings.DATABASE_NAME == \
+           settings.OTHER_DATABASES['django_test_db_a']['DATABASE_NAME']
+    assert model_connection_name(MY) == _default
+    assert MY._default_manager.db.connection.settings.DATABASE_NAME == \
+           settings.DATABASE_NAME, "%s != %s" % \
+           (MY._default_manager.db.connection.settings.DATABASE_NAME,
+            settings.DATABASE_NAME)
+    
+
+# helpers
+class MockHandler(WSGIHandler):
+
+    def __init__(self, test):
+        self.test = test
+        super(MockHandler, self).__init__()
+        
+    def get_response(self, path, request):
+        # debug("mock handler answering %s, %s", path, request)
+        return HttpResponse(self.test(path, request))
+        
+
+def pr(*arg):
+    if S['verbosity'] >= 1:
+        msg, arg = arg[0], arg[1:]
+        print msg % arg
+
+def debug(*arg):
+    if S['verbosity'] >= 2:
+        msg, arg = arg[0], arg[1:]
+        print msg % arg
+
+def setup():
+    debug("setup")
+    S['ODB'] = copy.deepcopy(settings.OTHER_DATABASES)
+    for sk in [ k for k in dir(settings) if k.startswith('DATABASE') ]:
+        S[sk] = getattr(settings, sk)
+    
+    settings.OTHER_DATABASES['django_test_db_a']['MODELS'] = ['ri.MX']
+    settings.OTHER_DATABASES['django_test_db_b']['MODELS'] = ['ri.MY']
+
+def teardown():
+    debug("teardown")
+    settings.OTHER_DATABASES = S['ODB']
+    for sk in [ k for k in S.keys() if k.startswith('DATABASE') ]:
+        setattr(settings, sk, S[sk])
+
+def start_response(code, headers):
+    debug("start response: %s %s", code, headers)
+    pass
+
+def main():
+    debug("running tests")
+
+    env = os.environ.copy()
+    env['PATH_INFO'] = '/'
+    env['REQUEST_METHOD'] = 'GET'
+    
+    MockHandler(test_one)(env, start_response)
+    settings.OTHER_DATABASES['django_test_db_b']['MODELS'] = []
+    MockHandler(test_two)(env, start_response)
+    
+def run_tests(verbosity=0):
+    S['verbosity'] = verbosity
+    setup()
+    try:
+        main()
+    finally:
+        teardown()
+
+        
+if __name__ == '__main__':
+    run_tests(2)