diff --git a/Lib/ast.py b/Lib/ast.py index 226910ecac0b4a..a307f3ecd06175 100644 --- a/Lib/ast.py +++ b/Lib/ast.py @@ -1051,7 +1051,8 @@ def visit_ClassDef(self, node): self.fill("@") self.traverse(deco) self.fill("class " + node.name) - self._type_params_helper(node.type_params) + if hasattr(node, "type_params"): + self._type_params_helper(node.type_params) with self.delimit_if("(", ")", condition = node.bases or node.keywords): comma = False for e in node.bases: @@ -1083,7 +1084,8 @@ def _function_helper(self, node, fill_suffix): self.traverse(deco) def_str = fill_suffix + " " + node.name self.fill(def_str) - self._type_params_helper(node.type_params) + if hasattr(node, "type_params"): + self._type_params_helper(node.type_params) with self.delimit("(", ")"): self.traverse(node.args) if node.returns: diff --git a/Lib/test/test_unparse.py b/Lib/test/test_unparse.py index 88c7c3a0af8771..41a6318d1499b4 100644 --- a/Lib/test/test_unparse.py +++ b/Lib/test/test_unparse.py @@ -1,4 +1,4 @@ -"""Tests for the unparse.py script in the Tools/parser directory.""" +"""Tests for ast.unparse.""" import unittest import test.support @@ -625,6 +625,78 @@ def test_star_expr_assign_target_multiple(self): self.check_src_roundtrip("a, b = [c, d] = e, f = g") +class ManualASTCreationTestCase(unittest.TestCase): + """Test that AST nodes created without a type_params field unparse correctly.""" + + def test_class(self): + node = ast.ClassDef(name="X", bases=[], keywords=[], body=[ast.Pass()], decorator_list=[]) + ast.fix_missing_locations(node) + self.assertEqual(ast.unparse(node), "class X:\n pass") + + def test_class_with_type_params(self): + node = ast.ClassDef(name="X", bases=[], keywords=[], body=[ast.Pass()], decorator_list=[], + type_params=[ast.TypeVar("T")]) + ast.fix_missing_locations(node) + self.assertEqual(ast.unparse(node), "class X[T]:\n pass") + + def test_function(self): + node = ast.FunctionDef( + name="f", + args=ast.arguments(posonlyargs=[], args=[], vararg=None, kwonlyargs=[], kw_defaults=[], kwarg=None, defaults=[]), + body=[ast.Pass()], + decorator_list=[], + returns=None, + ) + ast.fix_missing_locations(node) + self.assertEqual(ast.unparse(node), "def f():\n pass") + + def test_function_with_type_params(self): + node = ast.FunctionDef( + name="f", + args=ast.arguments(posonlyargs=[], args=[], vararg=None, kwonlyargs=[], kw_defaults=[], kwarg=None, defaults=[]), + body=[ast.Pass()], + decorator_list=[], + returns=None, + type_params=[ast.TypeVar("T")], + ) + ast.fix_missing_locations(node) + self.assertEqual(ast.unparse(node), "def f[T]():\n pass") + + def test_function_with_type_params_and_bound(self): + node = ast.FunctionDef( + name="f", + args=ast.arguments(posonlyargs=[], args=[], vararg=None, kwonlyargs=[], kw_defaults=[], kwarg=None, defaults=[]), + body=[ast.Pass()], + decorator_list=[], + returns=None, + type_params=[ast.TypeVar("T", bound=ast.Name("int"))], + ) + ast.fix_missing_locations(node) + self.assertEqual(ast.unparse(node), "def f[T: int]():\n pass") + + def test_async_function(self): + node = ast.AsyncFunctionDef( + name="f", + args=ast.arguments(posonlyargs=[], args=[], vararg=None, kwonlyargs=[], kw_defaults=[], kwarg=None, defaults=[]), + body=[ast.Pass()], + decorator_list=[], + returns=None, + ) + ast.fix_missing_locations(node) + self.assertEqual(ast.unparse(node), "async def f():\n pass") + + def test_async_function_with_type_params(self): + node = ast.AsyncFunctionDef( + name="f", + args=ast.arguments(posonlyargs=[], args=[], vararg=None, kwonlyargs=[], kw_defaults=[], kwarg=None, defaults=[]), + body=[ast.Pass()], + decorator_list=[], + returns=None, + type_params=[ast.TypeVar("T")], + ) + ast.fix_missing_locations(node) + self.assertEqual(ast.unparse(node), "async def f[T]():\n pass") + class DirectoryTestCase(ASTTestCase): """Test roundtrip behaviour on all files in Lib and Lib/test.""" diff --git a/Misc/NEWS.d/next/Library/2023-06-15-18-11-47.gh-issue-104799.BcLzbP.rst b/Misc/NEWS.d/next/Library/2023-06-15-18-11-47.gh-issue-104799.BcLzbP.rst new file mode 100644 index 00000000000000..d0dbff4f1553e2 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2023-06-15-18-11-47.gh-issue-104799.BcLzbP.rst @@ -0,0 +1,3 @@ +Enable :func:`ast.unparse` to unparse function and class definitions created +without the new ``type_params`` field from :pep:`695`. Patch by Jelle +Zijlstra.