gh-116126: Implement PEP 696 (#116129)

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
Co-authored-by: Shantanu <12621235+hauntsaninja@users.noreply.github.com>

1 files changed, 42 insertions, 0 deletions

diff --git a/Lib/test/test_unparse.py b/Lib/test/test_unparse.py
index bb15f64..35394f2 100644
--- a/Lib/test/test_unparse.py
+++ b/Lib/test/test_unparse.py
@@ -673,6 +673,20 @@ class CosmeticTestCase(ASTTestCase):
         self.check_ast_roundtrip("""f'\\'{x:\\"}' """)
         self.check_ast_roundtrip("""f'\\'{x:\\\\"}' """)
 
+    def test_type_params(self):
+        self.check_ast_roundtrip("type A = int")
+        self.check_ast_roundtrip("type A[T] = int")
+        self.check_ast_roundtrip("type A[T: int] = int")
+        self.check_ast_roundtrip("type A[T = int] = int")
+        self.check_ast_roundtrip("type A[T: int = int] = int")
+        self.check_ast_roundtrip("type A[**P] = int")
+        self.check_ast_roundtrip("type A[**P = int] = int")
+        self.check_ast_roundtrip("type A[*Ts] = int")
+        self.check_ast_roundtrip("type A[*Ts = int] = int")
+        self.check_ast_roundtrip("type A[*Ts = *int] = int")
+        self.check_ast_roundtrip("def f[T: int = int, **P = int, *Ts = *int]():\n    pass")
+        self.check_ast_roundtrip("class C[T: int = int, **P = int, *Ts = *int]():\n    pass")
+
 
 class ManualASTCreationTestCase(unittest.TestCase):
     """Test that AST nodes created without a type_params field unparse correctly."""
@@ -723,6 +737,20 @@ class ManualASTCreationTestCase(unittest.TestCase):
         ast.fix_missing_locations(node)
         self.assertEqual(ast.unparse(node), "def f[T: int]():\n    pass")
 
+    def test_function_with_type_params_and_default(self):
+        node = ast.FunctionDef(
+            name="f",
+            args=ast.arguments(),
+            body=[ast.Pass()],
+            type_params=[
+                ast.TypeVar("T", default_value=ast.Constant(value=1)),
+                ast.TypeVarTuple("Ts", default_value=ast.Starred(value=ast.Constant(value=1), ctx=ast.Load())),
+                ast.ParamSpec("P", default_value=ast.Constant(value=1)),
+            ],
+        )
+        ast.fix_missing_locations(node)
+        self.assertEqual(ast.unparse(node), "def f[T = 1, *Ts = *1, **P = 1]():\n    pass")
+
     def test_async_function(self):
         node = ast.AsyncFunctionDef(
             name="f",
@@ -746,6 +774,20 @@ class ManualASTCreationTestCase(unittest.TestCase):
         ast.fix_missing_locations(node)
         self.assertEqual(ast.unparse(node), "async def f[T]():\n    pass")
 
+    def test_async_function_with_type_params_and_default(self):
+        node = ast.AsyncFunctionDef(
+            name="f",
+            args=ast.arguments(),
+            body=[ast.Pass()],
+            type_params=[
+                ast.TypeVar("T", default_value=ast.Constant(value=1)),
+                ast.TypeVarTuple("Ts", default_value=ast.Starred(value=ast.Constant(value=1), ctx=ast.Load())),
+                ast.ParamSpec("P", default_value=ast.Constant(value=1)),
+            ],
+        )
+        ast.fix_missing_locations(node)
+        self.assertEqual(ast.unparse(node), "async def f[T = 1, *Ts = *1, **P = 1]():\n    pass")
+
 
 class DirectoryTestCase(ASTTestCase):
     """Test roundtrip behaviour on all files in Lib and Lib/test."""