From: Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com>
Date: Sun, 5 Dec 2021 21:02:47 +0000 (-0800)
Subject: bpo-45662: Fix the repr of InitVar with a type alias to the built-in class (GH-29291)
X-Git-Tag: v3.10.1~5
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=f1dd5ed1f35a7ed5c3833c822e9965de2400d77e;p=thirdparty%2FPython%2Fcpython.git

bpo-45662: Fix the repr of InitVar with a type alias to the built-in class (GH-29291)


For example, InitVar[list[int]].
(cherry picked from commit 1fd4de5bddbbf2a97cdbac4d298c89e1156bdc6c)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
---

diff --git a/Lib/dataclasses.py b/Lib/dataclasses.py
index b3a9194d9d06..fe4094b891b4 100644
--- a/Lib/dataclasses.py
+++ b/Lib/dataclasses.py
@@ -229,7 +229,7 @@ class InitVar:
         self.type = type
 
     def __repr__(self):
-        if isinstance(self.type, type):
+        if isinstance(self.type, type) and not isinstance(self.type, GenericAlias):
             type_name = self.type.__name__
         else:
             # typing objects, e.g. List[int]
diff --git a/Lib/test/test_dataclasses.py b/Lib/test/test_dataclasses.py
index bcd004f4ec3a..47075df8d59f 100644
--- a/Lib/test/test_dataclasses.py
+++ b/Lib/test/test_dataclasses.py
@@ -1126,6 +1126,10 @@ class TestCase(unittest.TestCase):
         self.assertEqual(repr(InitVar[int]), 'dataclasses.InitVar[int]')
         self.assertEqual(repr(InitVar[List[int]]),
                          'dataclasses.InitVar[typing.List[int]]')
+        self.assertEqual(repr(InitVar[list[int]]),
+                         'dataclasses.InitVar[list[int]]')
+        self.assertEqual(repr(InitVar[int|str]),
+                         'dataclasses.InitVar[int | str]')
 
     def test_init_var_inheritance(self):
         # Note that this deliberately tests that a dataclass need not
diff --git a/Misc/NEWS.d/next/Library/2021-10-28-22-58-14.bpo-45662.sJd7Ir.rst b/Misc/NEWS.d/next/Library/2021-10-28-22-58-14.bpo-45662.sJd7Ir.rst
new file mode 100644
index 000000000000..050b443dd7cb
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2021-10-28-22-58-14.bpo-45662.sJd7Ir.rst
@@ -0,0 +1,2 @@
+Fix the repr of :data:`dataclasses.InitVar` with a type alias to the
+built-in class, e.g. ``InitVar[list[int]]``.