check for TypeDecorator when handling getitem

Fixed issue where :class:`.TypeDecorator` would not correctly proxy the
``__getitem__()`` operator when decorating the :class:`.ARRAY` datatype,
without explicit workarounds.

Fixes: #7249
Change-Id: I3273572b4757e41fb5952639cb867314227d368a

1 files changed, 130 insertions, 0 deletions

diff --git a/test/sql/test_types.py b/test/sql/test_types.py
index a154666bb..a608d0040 100644
--- a/test/sql/test_types.py
+++ b/test/sql/test_types.py
@@ -782,6 +782,136 @@ class UserDefinedRoundTripTest(_UserDefinedTypeFixture, fixtures.TablesTest):
         eq_(result.fetchall(), [(3, 1500), (4, 900)])
 
 
+class TypeDecoratorSpecialCasesTest(AssertsCompiledSQL, fixtures.TestBase):
+    __backend__ = True
+
+    @testing.requires.array_type
+    def test_typedec_of_array_modified(self, metadata, connection):
+        """test #7249"""
+
+        class SkipsFirst(TypeDecorator):  # , Indexable):
+            impl = ARRAY(Integer, zero_indexes=True)
+
+            cache_ok = True
+
+            def process_bind_param(self, value, dialect):
+                return value[1:]
+
+            def copy(self, **kw):
+                return SkipsFirst(**kw)
+
+            def coerce_compared_value(self, op, value):
+                return self.impl.coerce_compared_value(op, value)
+
+        t = Table(
+            "t",
+            metadata,
+            Column("id", Integer, primary_key=True),
+            Column("data", SkipsFirst),
+        )
+        t.create(connection)
+
+        connection.execute(t.insert(), {"data": [1, 2, 3]})
+        val = connection.scalar(select(t.c.data))
+        eq_(val, [2, 3])
+
+        val = connection.scalar(select(t.c.data[0]))
+        eq_(val, 2)
+
+    def test_typedec_of_array_ops(self):
+        class ArrayDec(TypeDecorator):
+            impl = ARRAY(Integer, zero_indexes=True)
+
+            cache_ok = True
+
+            def coerce_compared_value(self, op, value):
+                return self.impl.coerce_compared_value(op, value)
+
+        expr1 = column("q", ArrayDec)[0]
+        expr2 = column("q", ARRAY(Integer, zero_indexes=True))[0]
+
+        eq_(expr1.right.type._type_affinity, Integer)
+        eq_(expr2.right.type._type_affinity, Integer)
+
+        self.assert_compile(
+            column("q", ArrayDec).any(7, operator=operators.lt),
+            "%(q_1)s < ANY (q)",
+            dialect="postgresql",
+        )
+
+        self.assert_compile(
+            column("q", ArrayDec)[5], "q[%(q_1)s]", dialect="postgresql"
+        )
+
+    def test_typedec_of_json_ops(self):
+        class JsonDec(TypeDecorator):
+            impl = JSON()
+
+            cache_ok = True
+
+        self.assert_compile(
+            column("q", JsonDec)["q"], "q -> %(q_1)s", dialect="postgresql"
+        )
+
+        self.assert_compile(
+            column("q", JsonDec)["q"].as_integer(),
+            "CAST(q ->> %(q_1)s AS INTEGER)",
+            dialect="postgresql",
+        )
+
+    @testing.requires.array_type
+    def test_typedec_of_array(self, metadata, connection):
+        """test #7249"""
+
+        class ArrayDec(TypeDecorator):
+            impl = ARRAY(Integer, zero_indexes=True)
+
+            cache_ok = True
+
+            def coerce_compared_value(self, op, value):
+                return self.impl.coerce_compared_value(op, value)
+
+        t = Table(
+            "t",
+            metadata,
+            Column("id", Integer, primary_key=True),
+            Column("data", ArrayDec),
+        )
+
+        t.create(connection)
+
+        connection.execute(t.insert(), {"data": [1, 2, 3]})
+        val = connection.scalar(select(t.c.data))
+        eq_(val, [1, 2, 3])
+
+        val = connection.scalar(select(t.c.data[0]))
+        eq_(val, 1)
+
+    @testing.requires.json_type
+    def test_typedec_of_json(self, metadata, connection):
+        """test #7249"""
+
+        class JsonDec(TypeDecorator):
+            impl = JSON()
+
+            cache_ok = True
+
+        t = Table(
+            "t",
+            metadata,
+            Column("id", Integer, primary_key=True),
+            Column("data", JsonDec),
+        )
+        t.create(connection)
+
+        connection.execute(t.insert(), {"data": {"key": "value"}})
+        val = connection.scalar(select(t.c.data))
+        eq_(val, {"key": "value"})
+
+        val = connection.scalar(select(t.c.data["key"].as_string()))
+        eq_(val, "value")
+
+
 class BindProcessorInsertValuesTest(UserDefinedRoundTripTest):
     """related to #6770, test that insert().values() applies to
     bound parameter handlers including the None value."""