Additions to support HAAlchemy plugin

- add a connect=True key to connection record to support
  pre-loading of _ConnectionRecord objects
- ensure _ConnectionRecord.close() leaves the record in a good
  state for reopening
- add _ConnectionRecord.record_info for persistent storage
- add "in_use" accessor based on fairy_ref being present or not
- allow for the exclusions system and SuiteRequirements to be
  usable without the full plugin_base setup.
- move some Python-env requirements to the importable
  requirements.py module.
- allow starttime to be queried
- add additional events for engine plugins
- have "dialect" be a first-class parameter to the pool,
  ensure the engine strategy supplies it up front

Change-Id: Ibf549f7a1766e49d335cd6f5e26bacfaef9a8229

4 files changed, 56 insertions, 8 deletions

diff --git a/lib/sqlalchemy/testing/config.py b/lib/sqlalchemy/testing/config.py
index da5997661..6648f9130 100644
--- a/lib/sqlalchemy/testing/config.py
+++ b/lib/sqlalchemy/testing/config.py
@@ -15,7 +15,11 @@ file_config = None
 test_schema = None
 test_schema_2 = None
 _current = None
-_skip_test_exception = None
+
+try:
+    from unittest import SkipTest as _skip_test_exception
+except ImportError:
+    _skip_test_exception = None
 
 
 class Config(object):
@@ -90,3 +94,4 @@ class Config(object):
 
 def skip_test(msg):
     raise _skip_test_exception(msg)
+
diff --git a/lib/sqlalchemy/testing/exclusions.py b/lib/sqlalchemy/testing/exclusions.py
index b672656a0..fb1041db3 100644
--- a/lib/sqlalchemy/testing/exclusions.py
+++ b/lib/sqlalchemy/testing/exclusions.py
@@ -109,21 +109,21 @@ class compound(object):
         else:
             all_fails._expect_success(config._current)
 
-    def _do(self, config, fn, *args, **kw):
+    def _do(self, cfg, fn, *args, **kw):
         for skip in self.skips:
-            if skip(config):
+            if skip(cfg):
                 msg = "'%s' : %s" % (
                     fn.__name__,
-                    skip._as_string(config)
+                    skip._as_string(cfg)
                 )
                 config.skip_test(msg)
 
         try:
             return_value = fn(*args, **kw)
         except Exception as ex:
-            self._expect_failure(config, ex, name=fn.__name__)
+            self._expect_failure(cfg, ex, name=fn.__name__)
         else:
-            self._expect_success(config, name=fn.__name__)
+            self._expect_success(cfg, name=fn.__name__)
             return return_value
 
     def _expect_failure(self, config, ex, name='block'):
@@ -208,8 +208,10 @@ class Predicate(object):
         if negate:
             bool_ = not negate
         return self.description % {
-            "driver": config.db.url.get_driver_name(),
-            "database": config.db.url.get_backend_name(),
+            "driver": config.db.url.get_driver_name()
+            if config else "<no driver>",
+            "database": config.db.url.get_backend_name()
+            if config else "<no database>",
             "doesnt_support": "doesn't support" if bool_ else "does support",
             "does_support": "does support" if bool_ else "doesn't support"
         }
diff --git a/lib/sqlalchemy/testing/plugin/plugin_base.py b/lib/sqlalchemy/testing/plugin/plugin_base.py
index fc9d71165..6581195df 100644
--- a/lib/sqlalchemy/testing/plugin/plugin_base.py
+++ b/lib/sqlalchemy/testing/plugin/plugin_base.py
@@ -267,6 +267,7 @@ def _engine_uri(options, file_config):
     if not db_urls:
         db_urls.append(file_config.get('db', 'default'))
 
+    config._current = None
     for db_url in db_urls:
         cfg = provision.setup_config(
             db_url, options, file_config, provision.FOLLOWER_IDENT)
diff --git a/lib/sqlalchemy/testing/requirements.py b/lib/sqlalchemy/testing/requirements.py
index a9370a30e..b0f466892 100644
--- a/lib/sqlalchemy/testing/requirements.py
+++ b/lib/sqlalchemy/testing/requirements.py
@@ -15,6 +15,8 @@ to provide specific inclusion/exclusions.
 
 """
 
+import sys
+
 from . import exclusions
 from .. import util
 
@@ -708,6 +710,44 @@ class SuiteRequirements(Requirements):
         )
 
     @property
+    def python2(self):
+        return exclusions.skip_if(
+            lambda: sys.version_info >= (3,),
+            "Python version 2.xx is required."
+        )
+
+    @property
+    def python3(self):
+        return exclusions.skip_if(
+            lambda: sys.version_info < (3,),
+            "Python version 3.xx is required."
+        )
+
+    @property
+    def cpython(self):
+        return exclusions.only_if(
+            lambda: util.cpython,
+            "cPython interpreter needed"
+        )
+
+    @property
+    def non_broken_pickle(self):
+        from sqlalchemy.util import pickle
+        return exclusions.only_if(
+            lambda: not util.pypy and pickle.__name__ == 'cPickle'
+                or sys.version_info >= (3, 2),
+            "Needs cPickle+cPython or newer Python 3 pickle"
+        )
+
+    @property
+    def predictable_gc(self):
+        """target platform must remove all cycles unconditionally when
+        gc.collect() is called, as well as clean out unreferenced subclasses.
+
+        """
+        return self.cpython
+
+    @property
     def no_coverage(self):
         """Test should be skipped if coverage is enabled.