From 76968f3a9078278e742011f25b6bef33b2895f30 Mon Sep 17 00:00:00 2001
From: correctmost <134317971+correctmost@users.noreply.github.com>
Date: Wed, 23 Oct 2024 13:35:35 -0400
Subject: [PATCH 1/3] Fix IndexError when typing._alias() has missing arguments

Closes #2513

(cherry picked from commit ca0230d876914290712b4478acc863ae974f3b2d)
---
 ChangeLog                     |  4 +++
 astroid/brain/brain_typing.py |  1 +
 tests/brain/test_typing.py    | 49 ++++++++++++++++++++++++++++++++++-
 3 files changed, 53 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 4d3de29097..d7f48a8d5d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -8,6 +8,10 @@ What's New in astroid 3.4.0?
 Release date: TBA
 
 
+* Fix crash when typing._alias() call is missing arguments.
+
+  Closes #2513
+
 
 What's New in astroid 3.3.6?
 ============================
diff --git a/astroid/brain/brain_typing.py b/astroid/brain/brain_typing.py
index 38b01778b1..5e3a0c90d6 100644
--- a/astroid/brain/brain_typing.py
+++ b/astroid/brain/brain_typing.py
@@ -257,6 +257,7 @@ def _looks_like_typing_alias(node: Call) -> bool:
         isinstance(node.func, Name)
         # TODO: remove _DeprecatedGenericAlias when Py3.14 min
         and node.func.name in {"_alias", "_DeprecatedGenericAlias"}
+        and len(node.args) == 2
         and (
             # _alias function works also for builtins object such as list and dict
             isinstance(node.args[0], (Attribute, Name))
diff --git a/tests/brain/test_typing.py b/tests/brain/test_typing.py
index 1e8e3eaf88..11b77b7f9e 100644
--- a/tests/brain/test_typing.py
+++ b/tests/brain/test_typing.py
@@ -4,7 +4,7 @@
 
 import pytest
 
-from astroid import builder
+from astroid import bases, builder, nodes
 from astroid.exceptions import InferenceError
 
 
@@ -23,3 +23,50 @@ def test_infer_typevar() -> None:
     )
     with pytest.raises(InferenceError):
         call_node.inferred()
+
+
+class TestTypingAlias:
+    def test_infer_typing_alias(self) -> None:
+        """
+        Test that _alias() calls can be inferred.
+        """
+        node = builder.extract_node(
+            """
+            from typing import _alias
+            x = _alias(int, float)
+            """
+        )
+        assert isinstance(node, nodes.Assign)
+        assert isinstance(node.value, nodes.Call)
+        inferred = next(node.value.infer())
+        assert isinstance(inferred, nodes.ClassDef)
+        assert len(inferred.bases) == 1
+        assert inferred.bases[0].name == "int"
+
+    @pytest.mark.parametrize(
+        "alias_args",
+        [
+            "",  # two missing arguments
+            "int",  # one missing argument
+            "int, float, tuple",  # one additional argument
+        ],
+    )
+    def test_infer_typing_alias_incorrect_number_of_arguments(
+        self, alias_args: str
+    ) -> None:
+        """
+        Regression test for: https://github.com/pylint-dev/astroid/issues/2513
+
+        Test that _alias() calls with the incorrect number of arguments can be inferred.
+        """
+        node = builder.extract_node(
+            f"""
+            from typing import _alias
+            x = _alias({alias_args})
+            """
+        )
+        assert isinstance(node, nodes.Assign)
+        assert isinstance(node.value, nodes.Call)
+        inferred = next(node.value.infer())
+        assert isinstance(inferred, bases.Instance)
+        assert inferred.name == "_SpecialGenericAlias"

From 78507c49d8cc7729dbfa3dc095330bea2806651d Mon Sep 17 00:00:00 2001
From: Pierre Sassoulas <pierre.sassoulas@gmail.com>
Date: Wed, 23 Oct 2024 20:42:03 +0200
Subject: [PATCH 2/3] Update ChangeLog

---
 ChangeLog | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index d7f48a8d5d..3e1546d0df 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -8,13 +8,13 @@ What's New in astroid 3.4.0?
 Release date: TBA
 
 
-* Fix crash when typing._alias() call is missing arguments.
-
-  Closes #2513
-
 
 What's New in astroid 3.3.6?
 ============================
+
+* Fix crash when typing._alias() call is missing arguments.
+
+  Closes #2513
 Release date: TBA
 
 

From 7bc02b7e04d85033903073a69e548b383bdc702a Mon Sep 17 00:00:00 2001
From: Pierre Sassoulas <pierre.sassoulas@gmail.com>
Date: Wed, 23 Oct 2024 20:42:34 +0200
Subject: [PATCH 3/3] Update ChangeLog

---
 ChangeLog | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 3e1546d0df..ee3824cf09 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -11,11 +11,11 @@ Release date: TBA
 
 What's New in astroid 3.3.6?
 ============================
+Release date: TBA
 
 * Fix crash when typing._alias() call is missing arguments.
 
   Closes #2513
-Release date: TBA