commit bbef7abe922edadc7a1679c19d6053240bf600d5
author Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> Sat Jun 23 08:04:01 2018 -0700
committer GitHub <noreply@github.com> Sat Jun 23 08:04:01 2018 -0700
tree 12ef3900638587c3aedab02dd2b6a0065bdf0d6d
parent efc6bf66a58e96c12116d65984ac69b0f36f85de

bpo-33805: Improve error message of dataclasses.replace() (GH-7580)

(cherry picked from commit 3d70f7aef614c396f516b5fccedeebe98598714d)

Co-authored-by: Dong-hee Na <donghee.na92@gmail.com>

Lib/test/test_dataclasses.py

diff --git a/Lib/test/test_dataclasses.py b/Lib/test/test_dataclasses.py
index 9297931..d9556c7 100755
--- a/Lib/test/test_dataclasses.py
+++ b/Lib/test/test_dataclasses.py
@@ -3024,6 +3024,22 @@
 
         replace(c, x=5)
 
+    def test_initvar_is_specified(self):
+        @dataclass
+        class C:
+            x: int
+            y: InitVar[int]
+
+            def __post_init__(self, y):
+                self.x *= y
+
+        c = C(1, 10)
+        self.assertEqual(c.x, 10)
+        with self.assertRaisesRegex(ValueError, r"InitVar 'y' must be "
+                                    "specified with replace()"):
+            replace(c, x=3)
+        c = replace(c, x=3, y=5)
+        self.assertEqual(c.x, 15)
     ## def test_initvar(self):
     ##     @dataclass
     ##     class C: