Make the GenericFunction registry fully case insensitive

Registered function names based on :class:`.GenericFunction` are now
retrieved in a case-insensitive fashion in all cases, removing the
deprecation logic from 1.3 which temporarily allowed multiple
:class:`.GenericFunction` objects to exist with differing cases.   A
:class:`.GenericFunction` that replaces another on the same name whether or
not it's case sensitive emits a warning before replacing the object.

Fixes: #4649
Change-Id: I265ae19833132db07ed5b5ae40c4d24f659b1ab3

2 files changed, 22 insertions, 155 deletions

diff --git a/test/sql/test_deprecations.py b/test/sql/test_deprecations.py
index 08a862e43..7990cd56c 100644
--- a/test/sql/test_deprecations.py
+++ b/test/sql/test_deprecations.py
@@ -1,17 +1,11 @@
 #! coding: utf-8
 
-from copy import deepcopy
-
-import pytest
-
 from sqlalchemy import bindparam
 from sqlalchemy import Column
 from sqlalchemy import column
 from sqlalchemy import create_engine
-from sqlalchemy import DateTime
 from sqlalchemy import exc
 from sqlalchemy import ForeignKey
-from sqlalchemy import func
 from sqlalchemy import Integer
 from sqlalchemy import MetaData
 from sqlalchemy import select
@@ -23,19 +17,14 @@ from sqlalchemy import text
 from sqlalchemy import util
 from sqlalchemy.engine import default
 from sqlalchemy.schema import DDL
-from sqlalchemy.sql import functions
 from sqlalchemy.sql import util as sql_util
-from sqlalchemy.sql.functions import GenericFunction
-from sqlalchemy.sql.sqltypes import NullType
 from sqlalchemy.testing import assert_raises
 from sqlalchemy.testing import assert_raises_message
 from sqlalchemy.testing import AssertsCompiledSQL
 from sqlalchemy.testing import engines
 from sqlalchemy.testing import eq_
 from sqlalchemy.testing import fixtures
-from sqlalchemy.testing import in_
 from sqlalchemy.testing import mock
-from sqlalchemy.testing import not_in_
 
 
 class DeprecationWarningsTest(fixtures.TestBase):
@@ -147,146 +136,6 @@ class DeprecationWarningsTest(fixtures.TestBase):
             )
 
 
-class CaseSensitiveFunctionDeprecationsTest(fixtures.TestBase):
-
-    def setup(self):
-        self._registry = deepcopy(functions._registry)
-        self._case_sensitive_registry = deepcopy(
-            functions._case_sensitive_registry)
-        functions._registry.clear()
-        functions._case_sensitive_registry.clear()
-
-    def teardown(self):
-        functions._registry = self._registry
-        functions._case_sensitive_registry = self._case_sensitive_registry
-
-    def test_case_sensitive(self):
-        reg = functions._registry['_default']
-        cs_reg = functions._case_sensitive_registry['_default']
-
-        class MYFUNC(GenericFunction):
-            type = DateTime
-
-        assert isinstance(func.MYFUNC().type, DateTime)
-        assert isinstance(func.MyFunc().type, DateTime)
-        assert isinstance(func.mYfUnC().type, DateTime)
-        assert isinstance(func.myfunc().type, DateTime)
-
-        in_("myfunc", reg)
-        not_in_("MYFUNC", reg)
-        not_in_("MyFunc", reg)
-        in_("myfunc", cs_reg)
-        eq_(set(cs_reg['myfunc'].keys()), set(['MYFUNC']))
-
-        with testing.expect_deprecated(
-            "GenericFunction 'MyFunc' is already registered with"
-            " different letter case, so the previously registered function "
-            "'MYFUNC' is switched into case-sensitive mode. "
-            "GenericFunction objects will be fully case-insensitive in a "
-            "future release.",
-            regex=False
-        ):
-            class MyFunc(GenericFunction):
-                type = Integer
-
-        assert isinstance(func.MYFUNC().type, DateTime)
-        assert isinstance(func.MyFunc().type, Integer)
-        with pytest.raises(AssertionError):
-            assert isinstance(func.mYfUnC().type, Integer)
-        with pytest.raises(AssertionError):
-            assert isinstance(func.myfunc().type, Integer)
-
-        eq_(reg["myfunc"], functions._CASE_SENSITIVE)
-        not_in_("MYFUNC", reg)
-        not_in_("MyFunc", reg)
-        in_("myfunc", cs_reg)
-        eq_(set(cs_reg['myfunc'].keys()), set(['MYFUNC', 'MyFunc']))
-
-    def test_replace_function_case_sensitive(self):
-        reg = functions._registry['_default']
-        cs_reg = functions._case_sensitive_registry['_default']
-
-        class replaceable_func(GenericFunction):
-            type = Integer
-            identifier = 'REPLACEABLE_FUNC'
-
-        assert isinstance(func.REPLACEABLE_FUNC().type, Integer)
-        assert isinstance(func.Replaceable_Func().type, Integer)
-        assert isinstance(func.RePlAcEaBlE_fUnC().type, Integer)
-        assert isinstance(func.replaceable_func().type, Integer)
-
-        in_("replaceable_func", reg)
-        not_in_("REPLACEABLE_FUNC", reg)
-        not_in_("Replaceable_Func", reg)
-        in_("replaceable_func", cs_reg)
-        eq_(set(cs_reg['replaceable_func'].keys()), set(['REPLACEABLE_FUNC']))
-
-        with testing.expect_deprecated(
-            "GenericFunction 'Replaceable_Func' is already registered with"
-            " different letter case, so the previously registered function "
-            "'REPLACEABLE_FUNC' is switched into case-sensitive mode. "
-            "GenericFunction objects will be fully case-insensitive in a "
-            "future release.",
-            regex=False
-        ):
-            class Replaceable_Func(GenericFunction):
-                type = DateTime
-                identifier = 'Replaceable_Func'
-
-        assert isinstance(func.REPLACEABLE_FUNC().type, Integer)
-        assert isinstance(func.Replaceable_Func().type, DateTime)
-        assert isinstance(func.RePlAcEaBlE_fUnC().type, NullType)
-        assert isinstance(func.replaceable_func().type, NullType)
-
-        eq_(reg["replaceable_func"], functions._CASE_SENSITIVE)
-        not_in_("REPLACEABLE_FUNC", reg)
-        not_in_("Replaceable_Func", reg)
-        in_("replaceable_func", cs_reg)
-        eq_(set(cs_reg['replaceable_func'].keys()),
-            set(['REPLACEABLE_FUNC', 'Replaceable_Func']))
-
-        with testing.expect_warnings(
-            "The GenericFunction 'REPLACEABLE_FUNC' is already registered and "
-            "is going to be overriden.",
-            regex=False
-        ):
-            class replaceable_func_override(GenericFunction):
-                type = DateTime
-                identifier = 'REPLACEABLE_FUNC'
-
-        with testing.expect_deprecated(
-            "GenericFunction(s) '['REPLACEABLE_FUNC', 'Replaceable_Func']' "
-            "are already registered with different letter cases and might "
-            "interact with 'replaceable_func'. GenericFunction objects will "
-            "be fully case-insensitive in a future release.",
-            regex=False
-        ):
-            class replaceable_func_lowercase(GenericFunction):
-                type = String
-                identifier = 'replaceable_func'
-
-        with testing.expect_warnings(
-            "The GenericFunction 'Replaceable_Func' is already registered and "
-            "is going to be overriden.",
-            regex=False
-        ):
-            class Replaceable_Func_override(GenericFunction):
-                type = Integer
-                identifier = 'Replaceable_Func'
-
-        assert isinstance(func.REPLACEABLE_FUNC().type, DateTime)
-        assert isinstance(func.Replaceable_Func().type, Integer)
-        assert isinstance(func.RePlAcEaBlE_fUnC().type, NullType)
-        assert isinstance(func.replaceable_func().type, String)
-
-        eq_(reg["replaceable_func"], functions._CASE_SENSITIVE)
-        not_in_("REPLACEABLE_FUNC", reg)
-        not_in_("Replaceable_Func", reg)
-        in_("replaceable_func", cs_reg)
-        eq_(set(cs_reg['replaceable_func'].keys()),
-            set(['REPLACEABLE_FUNC', 'Replaceable_Func', 'replaceable_func']))
-
-
 class DDLListenerDeprecationsTest(fixtures.TestBase):
     def setup(self):
         self.bind = self.engine = engines.mock_engine()
diff --git a/test/sql/test_functions.py b/test/sql/test_functions.py
index b03b156bc..ac711c669 100644
--- a/test/sql/test_functions.py
+++ b/test/sql/test_functions.py
@@ -57,12 +57,9 @@ class CompileTest(fixtures.TestBase, AssertsCompiledSQL):
 
     def setup(self):
         self._registry = deepcopy(functions._registry)
-        self._case_sensitive_registry = deepcopy(
-            functions._case_sensitive_registry)
 
     def teardown(self):
         functions._registry = self._registry
-        functions._case_sensitive_registry = self._case_sensitive_registry
 
     def test_compile(self):
         for dialect in all_dialects(exclude=("sybase",)):
@@ -96,7 +93,6 @@ class CompileTest(fixtures.TestBase, AssertsCompiledSQL):
             )
 
             functions._registry['_default'].pop('fake_func')
-            functions._case_sensitive_registry['_default'].pop('fake_func')
 
     def test_use_labels(self):
         self.assert_compile(
@@ -261,6 +257,28 @@ class CompileTest(fixtures.TestBase, AssertsCompiledSQL):
         assert isinstance(func.RePlAcEaBlE_fUnC().type, DateTime)
         assert isinstance(func.replaceable_func().type, DateTime)
 
+    def test_replace_function_case_insensitive(self):
+        class replaceable_func(GenericFunction):
+            type = Integer
+            identifier = 'replaceable_func'
+
+        assert isinstance(func.Replaceable_Func().type, Integer)
+        assert isinstance(func.RePlAcEaBlE_fUnC().type, Integer)
+        assert isinstance(func.replaceable_func().type, Integer)
+
+        with expect_warnings(
+            "The GenericFunction 'replaceable_func' is already registered and "
+            "is going to be overriden.",
+            regex=False
+        ):
+            class replaceable_func_override(GenericFunction):
+                type = DateTime
+                identifier = 'REPLACEABLE_Func'
+
+        assert isinstance(func.Replaceable_Func().type, DateTime)
+        assert isinstance(func.RePlAcEaBlE_fUnC().type, DateTime)
+        assert isinstance(func.replaceable_func().type, DateTime)
+
     def test_custom_w_custom_name(self):
         class myfunc(GenericFunction):
             name = "notmyfunc"