From 182c18a97fa524950db7cac9540b5fdf926f346c Mon Sep 17 00:00:00 2001
From: hauntsaninja <>
Date: Mon, 11 Apr 2022 00:35:47 -0400
Subject: [PATCH 1/3] Recognise LiteralString as str

Linking #12554
---
 mypy/nodes.py                             |  3 +++
 test-data/unit/check-type-aliases.test    | 18 ++++++++++++++++++
 test-data/unit/fixtures/typing-medium.pyi |  1 +
 3 files changed, 22 insertions(+)

diff --git a/mypy/nodes.py b/mypy/nodes.py
index 7fcf5d85673c..5682ae49f77e 100644
--- a/mypy/nodes.py
+++ b/mypy/nodes.py
@@ -123,6 +123,7 @@ def get_column(self) -> int:
     'typing.DefaultDict': 'collections.defaultdict',
     'typing.Deque': 'collections.deque',
     'typing.OrderedDict': 'collections.OrderedDict',
+    'typing.LiteralString': 'builtins.str',  # a lie in lieu of actual support for PEP 675
 }
 
 # This keeps track of the oldest supported Python version where the corresponding
@@ -137,12 +138,14 @@ def get_column(self) -> int:
     'typing.DefaultDict': (2, 7),
     'typing.Deque': (2, 7),
     'typing.OrderedDict': (3, 7),
+    'typing.LiteralString': (3, 11),
 }
 
 # This keeps track of aliases in `typing_extensions`, which we treat specially.
 typing_extensions_aliases: Final = {
     # See: https://github.com/python/mypy/issues/11528
     'typing_extensions.OrderedDict': 'collections.OrderedDict',
+    'typing_extensions.LiteralString': 'builtins.str',  # a lie in lieu of actual support for PEP 675
 }
 
 reverse_builtin_aliases: Final = {
diff --git a/test-data/unit/check-type-aliases.test b/test-data/unit/check-type-aliases.test
index 61d53870d724..111743e9235e 100644
--- a/test-data/unit/check-type-aliases.test
+++ b/test-data/unit/check-type-aliases.test
@@ -752,3 +752,21 @@ from typing_extensions import TypeAlias
 A: TypeAlias = str
 [builtins fixtures/bool.pyi]
 [out]
+
+
+[case testLiteralStringPep675]
+# flags: --python-version 3.11
+from typing import LiteralString as tpLS
+from typing_extensions import LiteralString as tpxLS
+
+def f(a: tpLS, b: tpxLS) -> None:
+    reveal_type(a)  # N: Revealed type is "builtins.str"
+    reveal_type(b)  # N: Revealed type is "builtins.str"
+
+# This isn't the correct behaviour, but should unblock use of LiteralString in typeshed
+f("asdf", "asdf")
+string: str
+f(string, string)
+
+[builtins fixtures/tuple.pyi]
+[typing fixtures/typing-medium.pyi]
diff --git a/test-data/unit/fixtures/typing-medium.pyi b/test-data/unit/fixtures/typing-medium.pyi
index 923ede2f0c00..568fe057c4cf 100644
--- a/test-data/unit/fixtures/typing-medium.pyi
+++ b/test-data/unit/fixtures/typing-medium.pyi
@@ -27,6 +27,7 @@ TypedDict = 0
 NoReturn = 0
 NewType = 0
 TypeAlias = 0
+LiteralString = 0
 
 T = TypeVar('T')
 T_co = TypeVar('T_co', covariant=True)

From 75054d488c84d7f1884202ee3c45173ee0337877 Mon Sep 17 00:00:00 2001
From: hauntsaninja <>
Date: Mon, 11 Apr 2022 00:43:09 -0400
Subject: [PATCH 2/3] okay flake8

---
 mypy/nodes.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/mypy/nodes.py b/mypy/nodes.py
index 5682ae49f77e..5f2d05717b02 100644
--- a/mypy/nodes.py
+++ b/mypy/nodes.py
@@ -123,7 +123,8 @@ def get_column(self) -> int:
     'typing.DefaultDict': 'collections.defaultdict',
     'typing.Deque': 'collections.deque',
     'typing.OrderedDict': 'collections.OrderedDict',
-    'typing.LiteralString': 'builtins.str',  # a lie in lieu of actual support for PEP 675
+    # a lie in lieu of actual support for PEP 675
+    'typing.LiteralString': 'builtins.str',
 }
 
 # This keeps track of the oldest supported Python version where the corresponding
@@ -145,7 +146,8 @@ def get_column(self) -> int:
 typing_extensions_aliases: Final = {
     # See: https://github.com/python/mypy/issues/11528
     'typing_extensions.OrderedDict': 'collections.OrderedDict',
-    'typing_extensions.LiteralString': 'builtins.str',  # a lie in lieu of actual support for PEP 675
+    # a lie in lieu of actual support for PEP 675
+    'typing_extensions.LiteralString': 'builtins.str',
 }
 
 reverse_builtin_aliases: Final = {

From 3dacbdf0c264d40799c6496d8c971a2229f0912c Mon Sep 17 00:00:00 2001
From: hauntsaninja <>
Date: Mon, 11 Apr 2022 01:06:05 -0400
Subject: [PATCH 3/3] fix test

---
 mypy/nodes.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/mypy/nodes.py b/mypy/nodes.py
index 5f2d05717b02..ff9276213ddc 100644
--- a/mypy/nodes.py
+++ b/mypy/nodes.py
@@ -123,7 +123,7 @@ def get_column(self) -> int:
     'typing.DefaultDict': 'collections.defaultdict',
     'typing.Deque': 'collections.deque',
     'typing.OrderedDict': 'collections.OrderedDict',
-    # a lie in lieu of actual support for PEP 675
+    # HACK: a lie in lieu of actual support for PEP 675
     'typing.LiteralString': 'builtins.str',
 }
 
@@ -146,7 +146,7 @@ def get_column(self) -> int:
 typing_extensions_aliases: Final = {
     # See: https://github.com/python/mypy/issues/11528
     'typing_extensions.OrderedDict': 'collections.OrderedDict',
-    # a lie in lieu of actual support for PEP 675
+    # HACK: a lie in lieu of actual support for PEP 675
     'typing_extensions.LiteralString': 'builtins.str',
 }
 
@@ -161,6 +161,8 @@ def get_column(self) -> int:
 _nongen_builtins.update((name, alias) for alias, name in type_aliases.items())
 # Drop OrderedDict from this for backward compatibility
 del _nongen_builtins['collections.OrderedDict']
+# HACK: consequence of hackily treating LiteralString as an alias for str
+del _nongen_builtins['builtins.str']
 
 
 def get_nongen_builtins(python_version: Tuple[int, int]) -> Dict[str, str]: