CAST the elements in ARRAYs when using psycopg2

Adjusted the psycopg2 dialect to emit an explicit PostgreSQL-style cast for
bound parameters that contain ARRAY elements. This allows the full range of
datatypes to function correctly within arrays. The asyncpg dialect already
generated these internal casts in the final statement. This also includes
support for array slice updates as well as the PostgreSQL-specific
:meth:`_postgresql.ARRAY.contains` method.

Fixes: #6023
Change-Id: Ia7519ac4371a635f05ac69a3a4d0f4e6d2f04cad

4 files changed, 50 insertions, 1 deletions

diff --git a/lib/sqlalchemy/testing/__init__.py b/lib/sqlalchemy/testing/__init__.py
index adbb8f643..a3ce24226 100644
--- a/lib/sqlalchemy/testing/__init__.py
+++ b/lib/sqlalchemy/testing/__init__.py
@@ -42,6 +42,7 @@ from .assertions import startswith_
 from .assertions import uses_deprecated
 from .config import async_test
 from .config import combinations
+from .config import combinations_list
 from .config import db
 from .config import fixture
 from .config import requirements as requires
diff --git a/lib/sqlalchemy/testing/config.py b/lib/sqlalchemy/testing/config.py
index 750671f9f..6589e5097 100644
--- a/lib/sqlalchemy/testing/config.py
+++ b/lib/sqlalchemy/testing/config.py
@@ -89,6 +89,11 @@ def combinations(*comb, **kw):
     return _fixture_functions.combinations(*comb, **kw)
 
 
+def combinations_list(arg_iterable, **kw):
+    "As combination, but takes a single iterable"
+    return combinations(*arg_iterable, **kw)
+
+
 def fixture(*arg, **kw):
     return _fixture_functions.fixture(*arg, **kw)
 
diff --git a/lib/sqlalchemy/testing/plugin/pytestplugin.py b/lib/sqlalchemy/testing/plugin/pytestplugin.py
index 4eaaecebb..388d71c73 100644
--- a/lib/sqlalchemy/testing/plugin/pytestplugin.py
+++ b/lib/sqlalchemy/testing/plugin/pytestplugin.py
@@ -578,7 +578,9 @@ class PytestFixtureFunctions(plugin_base.FixtureFunctions):
         "i": lambda obj: obj,
         "r": repr,
         "s": str,
-        "n": operator.attrgetter("__name__"),
+        "n": lambda obj: obj.__name__
+        if hasattr(obj, "__name__")
+        else type(obj).__name__,
     }
 
     def combinations(self, *arg_sets, **kw):
diff --git a/lib/sqlalchemy/testing/schema.py b/lib/sqlalchemy/testing/schema.py
index 22b1f7b77..fee021cff 100644
--- a/lib/sqlalchemy/testing/schema.py
+++ b/lib/sqlalchemy/testing/schema.py
@@ -5,11 +5,14 @@
 # This module is part of SQLAlchemy and is released under
 # the MIT License: http://www.opensource.org/licenses/mit-license.php
 
+import sys
+
 from . import config
 from . import exclusions
 from .. import event
 from .. import schema
 from .. import types as sqltypes
+from ..util import OrderedDict
 
 
 __all__ = ["Table", "Column"]
@@ -162,3 +165,41 @@ def _truncate_name(dialect, name):
         )
     else:
         return name
+
+
+def pep435_enum(name):
+    # Implements PEP 435 in the minimal fashion needed by SQLAlchemy
+    __members__ = OrderedDict()
+
+    def __init__(self, name, value, alias=None):
+        self.name = name
+        self.value = value
+        self.__members__[name] = self
+        value_to_member[value] = self
+        setattr(self.__class__, name, self)
+        if alias:
+            self.__members__[alias] = self
+            setattr(self.__class__, alias, self)
+
+    value_to_member = {}
+
+    @classmethod
+    def get(cls, value):
+        return value_to_member[value]
+
+    someenum = type(
+        name,
+        (object,),
+        {"__members__": __members__, "__init__": __init__, "get": get},
+    )
+
+    # getframe() trick for pickling I don't understand courtesy
+    # Python namedtuple()
+    try:
+        module = sys._getframe(1).f_globals.get("__name__", "__main__")
+    except (AttributeError, ValueError):
+        pass
+    if module is not None:
+        someenum.__module__ = module
+
+    return someenum