Tests fail gracefully if tpc is supported but disabled by the server.

tests/test_connection.py

@@ -67,6 +67,32 @@ class ConnectionTests(unittest.TestCase):
         self.assert_(conn.encoding in psycopg2.extensions.encodings)
 
 
+def skip_if_tpc_disabled(f):
+    """Skip a test if the server has tpc support disabled."""
+    def skip_if_tpc_disabled_(self):
+        cnn = self.connect()
+        cur = cnn.cursor()
+        try:
+            cur.execute("SHOW max_prepared_transactions;")
+        except psycopg2.ProgrammingError:
+            # Server version too old: let's die a different death
+            mtp = 1
+        else:
+            mtp = int(cur.fetchone()[0])
+        finally:
+            cnn.close()
+
+        if not mtp:
+            import warnings
+            warnings.warn(
+                "server not configured for two phase transactions. "
+                "set max_prepared_transactions to > 0 to run the test")
+            return
+        return f(self)
+
+    skip_if_tpc_disabled_.__name__ = f.__name__
+    return skip_if_tpc_disabled_
+
 class ConnectionTwoPhaseTests(unittest.TestCase):
     def setUp(self):
         self.make_test_table()
@@ -120,6 +146,7 @@ class ConnectionTwoPhaseTests(unittest.TestCase):
     def connect(self):
         return psycopg2.connect(tests.dsn)
 
+    @skip_if_tpc_disabled
     def test_tpc_commit(self):
         cnn = self.connect()
         xid = cnn.xid(1, "gtrid", "bqual")
@@ -161,6 +188,7 @@ class ConnectionTwoPhaseTests(unittest.TestCase):
         self.assertEqual(0, self.count_xacts())
         self.assertEqual(1, self.count_test_records())
 
+    @skip_if_tpc_disabled
     def test_tpc_commit_recovered(self):
         cnn = self.connect()
         xid = cnn.xid(1, "gtrid", "bqual")
@@ -187,6 +215,7 @@ class ConnectionTwoPhaseTests(unittest.TestCase):
         self.assertEqual(0, self.count_xacts())
         self.assertEqual(1, self.count_test_records())
 
+    @skip_if_tpc_disabled
     def test_tpc_rollback(self):
         cnn = self.connect()
         xid = cnn.xid(1, "gtrid", "bqual")
@@ -228,6 +257,7 @@ class ConnectionTwoPhaseTests(unittest.TestCase):
         self.assertEqual(0, self.count_xacts())
         self.assertEqual(0, self.count_test_records())
 
+    @skip_if_tpc_disabled
     def test_tpc_rollback_recovered(self):
         cnn = self.connect()
         xid = cnn.xid(1, "gtrid", "bqual")
@@ -266,6 +296,7 @@ class ConnectionTwoPhaseTests(unittest.TestCase):
         xns = cnn.tpc_recover()
         self.assertEqual(psycopg2.extensions.STATUS_BEGIN, cnn.status)
 
+    @skip_if_tpc_disabled
     def test_recovered_xids(self):
         # insert a few test xns
         cnn = self.connect()
@@ -296,6 +327,7 @@ class ConnectionTwoPhaseTests(unittest.TestCase):
             self.assertEqual(xid.owner, owner)
             self.assertEqual(xid.database, database)
 
+    @skip_if_tpc_disabled
     def test_xid_encoding(self):
         cnn = self.connect()
         xid = cnn.xid(42, "gtrid", "bqual")
@@ -308,6 +340,7 @@ class ConnectionTwoPhaseTests(unittest.TestCase):
             (tests.dbname,))
         self.assertEqual('42_Z3RyaWQ=_YnF1YWw=', cur.fetchone()[0])
 
+    @skip_if_tpc_disabled
     def test_xid_roundtrip(self):
         for fid, gtrid, bqual in [
             (0, "", ""),
@@ -331,6 +364,7 @@ class ConnectionTwoPhaseTests(unittest.TestCase):
 
             cnn.tpc_rollback(xid)
 
+    @skip_if_tpc_disabled
     def test_unparsed_roundtrip(self):
         for tid in [
             '',
@@ -383,6 +417,7 @@ class ConnectionTwoPhaseTests(unittest.TestCase):
         x2 = Xid.from_string('99_xxx_yyy')
         self.assertEqual(str(x2), '99_xxx_yyy')
 
+    @skip_if_tpc_disabled
     def test_xid_unicode(self):
         cnn = self.connect()
         x1 = cnn.xid(10, u'uni', u'code')
@@ -395,6 +430,7 @@ class ConnectionTwoPhaseTests(unittest.TestCase):
         self.assertEqual('uni', xid.gtrid)
         self.assertEqual('code', xid.bqual)
 
+    @skip_if_tpc_disabled
     def test_xid_unicode_unparsed(self):
         # We don't expect people shooting snowmen as transaction ids,
         # so if something explodes in an encode error I don't mind.