| """Tests for the unparse.py script in the Tools/parser directory.""" | 
 |  | 
 | import unittest | 
 | import test.support | 
 | import pathlib | 
 | import random | 
 | import tokenize | 
 | import ast | 
 |  | 
 |  | 
 | def read_pyfile(filename): | 
 |     """Read and return the contents of a Python source file (as a | 
 |     string), taking into account the file encoding.""" | 
 |     with tokenize.open(filename) as stream: | 
 |         return stream.read() | 
 |  | 
 |  | 
 | for_else = """\ | 
 | def f(): | 
 |     for x in range(10): | 
 |         break | 
 |     else: | 
 |         y = 2 | 
 |     z = 3 | 
 | """ | 
 |  | 
 | while_else = """\ | 
 | def g(): | 
 |     while True: | 
 |         break | 
 |     else: | 
 |         y = 2 | 
 |     z = 3 | 
 | """ | 
 |  | 
 | relative_import = """\ | 
 | from . import fred | 
 | from .. import barney | 
 | from .australia import shrimp as prawns | 
 | """ | 
 |  | 
 | nonlocal_ex = """\ | 
 | def f(): | 
 |     x = 1 | 
 |     def g(): | 
 |         nonlocal x | 
 |         x = 2 | 
 |         y = 7 | 
 |         def h(): | 
 |             nonlocal x, y | 
 | """ | 
 |  | 
 | # also acts as test for 'except ... as ...' | 
 | raise_from = """\ | 
 | try: | 
 |     1 / 0 | 
 | except ZeroDivisionError as e: | 
 |     raise ArithmeticError from e | 
 | """ | 
 |  | 
 | class_decorator = """\ | 
 | @f1(arg) | 
 | @f2 | 
 | class Foo: pass | 
 | """ | 
 |  | 
 | elif1 = """\ | 
 | if cond1: | 
 |     suite1 | 
 | elif cond2: | 
 |     suite2 | 
 | else: | 
 |     suite3 | 
 | """ | 
 |  | 
 | elif2 = """\ | 
 | if cond1: | 
 |     suite1 | 
 | elif cond2: | 
 |     suite2 | 
 | """ | 
 |  | 
 | try_except_finally = """\ | 
 | try: | 
 |     suite1 | 
 | except ex1: | 
 |     suite2 | 
 | except ex2: | 
 |     suite3 | 
 | else: | 
 |     suite4 | 
 | finally: | 
 |     suite5 | 
 | """ | 
 |  | 
 | try_except_star_finally = """\ | 
 | try: | 
 |     suite1 | 
 | except* ex1: | 
 |     suite2 | 
 | except* ex2: | 
 |     suite3 | 
 | else: | 
 |     suite4 | 
 | finally: | 
 |     suite5 | 
 | """ | 
 |  | 
 | with_simple = """\ | 
 | with f(): | 
 |     suite1 | 
 | """ | 
 |  | 
 | with_as = """\ | 
 | with f() as x: | 
 |     suite1 | 
 | """ | 
 |  | 
 | with_two_items = """\ | 
 | with f() as x, g() as y: | 
 |     suite1 | 
 | """ | 
 |  | 
 | docstring_prefixes = ( | 
 |     "", | 
 |     "class foo:\n    ", | 
 |     "def foo():\n    ", | 
 |     "async def foo():\n    ", | 
 | ) | 
 |  | 
 | class ASTTestCase(unittest.TestCase): | 
 |     def assertASTEqual(self, ast1, ast2): | 
 |         # Ensure the comparisons start at an AST node | 
 |         self.assertIsInstance(ast1, ast.AST) | 
 |         self.assertIsInstance(ast2, ast.AST) | 
 |  | 
 |         # An AST comparison routine modeled after ast.dump(), but | 
 |         # instead of string building, it traverses the two trees | 
 |         # in lock-step. | 
 |         def traverse_compare(a, b, missing=object()): | 
 |             if type(a) is not type(b): | 
 |                 self.fail(f"{type(a)!r} is not {type(b)!r}") | 
 |             if isinstance(a, ast.AST): | 
 |                 for field in a._fields: | 
 |                     value1 = getattr(a, field, missing) | 
 |                     value2 = getattr(b, field, missing) | 
 |                     # Singletons are equal by definition, so further | 
 |                     # testing can be skipped. | 
 |                     if value1 is not value2: | 
 |                         traverse_compare(value1, value2) | 
 |             elif isinstance(a, list): | 
 |                 try: | 
 |                     for node1, node2 in zip(a, b, strict=True): | 
 |                         traverse_compare(node1, node2) | 
 |                 except ValueError: | 
 |                     # Attempt a "pretty" error ala assertSequenceEqual() | 
 |                     len1 = len(a) | 
 |                     len2 = len(b) | 
 |                     if len1 > len2: | 
 |                         what = "First" | 
 |                         diff = len1 - len2 | 
 |                     else: | 
 |                         what = "Second" | 
 |                         diff = len2 - len1 | 
 |                     msg = f"{what} list contains {diff} additional elements." | 
 |                     raise self.failureException(msg) from None | 
 |             elif a != b: | 
 |                 self.fail(f"{a!r} != {b!r}") | 
 |         traverse_compare(ast1, ast2) | 
 |  | 
 |     def check_ast_roundtrip(self, code1, **kwargs): | 
 |         with self.subTest(code1=code1, ast_parse_kwargs=kwargs): | 
 |             ast1 = ast.parse(code1, **kwargs) | 
 |             code2 = ast.unparse(ast1) | 
 |             ast2 = ast.parse(code2, **kwargs) | 
 |             self.assertASTEqual(ast1, ast2) | 
 |  | 
 |     def check_invalid(self, node, raises=ValueError): | 
 |         with self.subTest(node=node): | 
 |             self.assertRaises(raises, ast.unparse, node) | 
 |  | 
 |     def get_source(self, code1, code2=None): | 
 |         code2 = code2 or code1 | 
 |         code1 = ast.unparse(ast.parse(code1)) | 
 |         return code1, code2 | 
 |  | 
 |     def check_src_roundtrip(self, code1, code2=None): | 
 |         code1, code2 = self.get_source(code1, code2) | 
 |         with self.subTest(code1=code1, code2=code2): | 
 |             self.assertEqual(code2, code1) | 
 |  | 
 |     def check_src_dont_roundtrip(self, code1, code2=None): | 
 |         code1, code2 = self.get_source(code1, code2) | 
 |         with self.subTest(code1=code1, code2=code2): | 
 |             self.assertNotEqual(code2, code1) | 
 |  | 
 | class UnparseTestCase(ASTTestCase): | 
 |     # Tests for specific bugs found in earlier versions of unparse | 
 |  | 
 |     def test_fstrings(self): | 
 |         self.check_ast_roundtrip("f'a'") | 
 |         self.check_ast_roundtrip("f'{{}}'") | 
 |         self.check_ast_roundtrip("f'{{5}}'") | 
 |         self.check_ast_roundtrip("f'{{5}}5'") | 
 |         self.check_ast_roundtrip("f'X{{}}X'") | 
 |         self.check_ast_roundtrip("f'{a}'") | 
 |         self.check_ast_roundtrip("f'{ {1:2}}'") | 
 |         self.check_ast_roundtrip("f'a{a}a'") | 
 |         self.check_ast_roundtrip("f'a{a}{a}a'") | 
 |         self.check_ast_roundtrip("f'a{a}a{a}a'") | 
 |         self.check_ast_roundtrip("f'{a!r}x{a!s}12{{}}{a!a}'") | 
 |         self.check_ast_roundtrip("f'{a:10}'") | 
 |         self.check_ast_roundtrip("f'{a:100_000{10}}'") | 
 |         self.check_ast_roundtrip("f'{a!r:10}'") | 
 |         self.check_ast_roundtrip("f'{a:a{b}10}'") | 
 |         self.check_ast_roundtrip( | 
 |                 "f'a{b}{c!s}{d!r}{e!a}{f:a}{g:a{b}}{h!s:a}" | 
 |                 "{j!s:{a}b}{k!s:a{b}c}{l!a:{b}c{d}}{x+y=}'" | 
 |         ) | 
 |  | 
 |     def test_fstrings_special_chars(self): | 
 |         # See issue 25180 | 
 |         self.check_ast_roundtrip(r"""f'{f"{0}"*3}'""") | 
 |         self.check_ast_roundtrip(r"""f'{f"{y}"*3}'""") | 
 |         self.check_ast_roundtrip("""f''""") | 
 |         self.check_ast_roundtrip('''f"""'end' "quote\\""""''') | 
 |  | 
 |     def test_fstrings_complicated(self): | 
 |         # See issue 28002 | 
 |         self.check_ast_roundtrip("""f'''{"'"}'''""") | 
 |         self.check_ast_roundtrip('''f\'\'\'-{f"""*{f"+{f'.{x}.'}+"}*"""}-\'\'\'''') | 
 |         self.check_ast_roundtrip('''f\'\'\'-{f"""*{f"+{f'.{x}.'}+"}*"""}-'single quote\\'\'\'\'''') | 
 |         self.check_ast_roundtrip('f"""{\'\'\'\n\'\'\'}"""') | 
 |         self.check_ast_roundtrip('f"""{g(\'\'\'\n\'\'\')}"""') | 
 |         self.check_ast_roundtrip('''f"a\\r\\nb"''') | 
 |         self.check_ast_roundtrip('''f"\\u2028{'x'}"''') | 
 |  | 
 |     def test_strings(self): | 
 |         self.check_ast_roundtrip("u'foo'") | 
 |         self.check_ast_roundtrip("r'foo'") | 
 |         self.check_ast_roundtrip("b'foo'") | 
 |  | 
 |     def test_del_statement(self): | 
 |         self.check_ast_roundtrip("del x, y, z") | 
 |  | 
 |     def test_shifts(self): | 
 |         self.check_ast_roundtrip("45 << 2") | 
 |         self.check_ast_roundtrip("13 >> 7") | 
 |  | 
 |     def test_for_else(self): | 
 |         self.check_ast_roundtrip(for_else) | 
 |  | 
 |     def test_while_else(self): | 
 |         self.check_ast_roundtrip(while_else) | 
 |  | 
 |     def test_unary_parens(self): | 
 |         self.check_ast_roundtrip("(-1)**7") | 
 |         self.check_ast_roundtrip("(-1.)**8") | 
 |         self.check_ast_roundtrip("(-1j)**6") | 
 |         self.check_ast_roundtrip("not True or False") | 
 |         self.check_ast_roundtrip("True or not False") | 
 |  | 
 |     def test_integer_parens(self): | 
 |         self.check_ast_roundtrip("3 .__abs__()") | 
 |  | 
 |     def test_huge_float(self): | 
 |         self.check_ast_roundtrip("1e1000") | 
 |         self.check_ast_roundtrip("-1e1000") | 
 |         self.check_ast_roundtrip("1e1000j") | 
 |         self.check_ast_roundtrip("-1e1000j") | 
 |  | 
 |     def test_nan(self): | 
 |         self.assertASTEqual( | 
 |             ast.parse(ast.unparse(ast.Constant(value=float('nan')))), | 
 |             ast.parse('1e1000 - 1e1000') | 
 |         ) | 
 |  | 
 |     def test_min_int(self): | 
 |         self.check_ast_roundtrip(str(-(2 ** 31))) | 
 |         self.check_ast_roundtrip(str(-(2 ** 63))) | 
 |  | 
 |     def test_imaginary_literals(self): | 
 |         self.check_ast_roundtrip("7j") | 
 |         self.check_ast_roundtrip("-7j") | 
 |         self.check_ast_roundtrip("0j") | 
 |         self.check_ast_roundtrip("-0j") | 
 |  | 
 |     def test_lambda_parentheses(self): | 
 |         self.check_ast_roundtrip("(lambda: int)()") | 
 |  | 
 |     def test_chained_comparisons(self): | 
 |         self.check_ast_roundtrip("1 < 4 <= 5") | 
 |         self.check_ast_roundtrip("a is b is c is not d") | 
 |  | 
 |     def test_function_arguments(self): | 
 |         self.check_ast_roundtrip("def f(): pass") | 
 |         self.check_ast_roundtrip("def f(a): pass") | 
 |         self.check_ast_roundtrip("def f(b = 2): pass") | 
 |         self.check_ast_roundtrip("def f(a, b): pass") | 
 |         self.check_ast_roundtrip("def f(a, b = 2): pass") | 
 |         self.check_ast_roundtrip("def f(a = 5, b = 2): pass") | 
 |         self.check_ast_roundtrip("def f(*, a = 1, b = 2): pass") | 
 |         self.check_ast_roundtrip("def f(*, a = 1, b): pass") | 
 |         self.check_ast_roundtrip("def f(*, a, b = 2): pass") | 
 |         self.check_ast_roundtrip("def f(a, b = None, *, c, **kwds): pass") | 
 |         self.check_ast_roundtrip("def f(a=2, *args, c=5, d, **kwds): pass") | 
 |         self.check_ast_roundtrip("def f(*args, **kwargs): pass") | 
 |  | 
 |     def test_relative_import(self): | 
 |         self.check_ast_roundtrip(relative_import) | 
 |  | 
 |     def test_nonlocal(self): | 
 |         self.check_ast_roundtrip(nonlocal_ex) | 
 |  | 
 |     def test_raise_from(self): | 
 |         self.check_ast_roundtrip(raise_from) | 
 |  | 
 |     def test_bytes(self): | 
 |         self.check_ast_roundtrip("b'123'") | 
 |  | 
 |     def test_annotations(self): | 
 |         self.check_ast_roundtrip("def f(a : int): pass") | 
 |         self.check_ast_roundtrip("def f(a: int = 5): pass") | 
 |         self.check_ast_roundtrip("def f(*args: [int]): pass") | 
 |         self.check_ast_roundtrip("def f(**kwargs: dict): pass") | 
 |         self.check_ast_roundtrip("def f() -> None: pass") | 
 |  | 
 |     def test_set_literal(self): | 
 |         self.check_ast_roundtrip("{'a', 'b', 'c'}") | 
 |  | 
 |     def test_empty_set(self): | 
 |         self.assertASTEqual( | 
 |             ast.parse(ast.unparse(ast.Set(elts=[]))), | 
 |             ast.parse('{*()}') | 
 |         ) | 
 |  | 
 |     def test_set_comprehension(self): | 
 |         self.check_ast_roundtrip("{x for x in range(5)}") | 
 |  | 
 |     def test_dict_comprehension(self): | 
 |         self.check_ast_roundtrip("{x: x*x for x in range(10)}") | 
 |  | 
 |     def test_class_decorators(self): | 
 |         self.check_ast_roundtrip(class_decorator) | 
 |  | 
 |     def test_class_definition(self): | 
 |         self.check_ast_roundtrip("class A(metaclass=type, *[], **{}): pass") | 
 |  | 
 |     def test_elifs(self): | 
 |         self.check_ast_roundtrip(elif1) | 
 |         self.check_ast_roundtrip(elif2) | 
 |  | 
 |     def test_try_except_finally(self): | 
 |         self.check_ast_roundtrip(try_except_finally) | 
 |  | 
 |     def test_try_except_star_finally(self): | 
 |         self.check_ast_roundtrip(try_except_star_finally) | 
 |  | 
 |     def test_starred_assignment(self): | 
 |         self.check_ast_roundtrip("a, *b, c = seq") | 
 |         self.check_ast_roundtrip("a, (*b, c) = seq") | 
 |         self.check_ast_roundtrip("a, *b[0], c = seq") | 
 |         self.check_ast_roundtrip("a, *(b, c) = seq") | 
 |  | 
 |     def test_with_simple(self): | 
 |         self.check_ast_roundtrip(with_simple) | 
 |  | 
 |     def test_with_as(self): | 
 |         self.check_ast_roundtrip(with_as) | 
 |  | 
 |     def test_with_two_items(self): | 
 |         self.check_ast_roundtrip(with_two_items) | 
 |  | 
 |     def test_dict_unpacking_in_dict(self): | 
 |         # See issue 26489 | 
 |         self.check_ast_roundtrip(r"""{**{'y': 2}, 'x': 1}""") | 
 |         self.check_ast_roundtrip(r"""{**{'y': 2}, **{'x': 1}}""") | 
 |  | 
 |     def test_slices(self): | 
 |         self.check_ast_roundtrip("a[i]") | 
 |         self.check_ast_roundtrip("a[i,]") | 
 |         self.check_ast_roundtrip("a[i, j]") | 
 |         # The AST for these next two both look like `a[(*a,)]` | 
 |         self.check_ast_roundtrip("a[(*a,)]") | 
 |         self.check_ast_roundtrip("a[*a]") | 
 |         self.check_ast_roundtrip("a[b, *a]") | 
 |         self.check_ast_roundtrip("a[*a, c]") | 
 |         self.check_ast_roundtrip("a[b, *a, c]") | 
 |         self.check_ast_roundtrip("a[*a, *a]") | 
 |         self.check_ast_roundtrip("a[b, *a, *a]") | 
 |         self.check_ast_roundtrip("a[*a, b, *a]") | 
 |         self.check_ast_roundtrip("a[*a, *a, b]") | 
 |         self.check_ast_roundtrip("a[b, *a, *a, c]") | 
 |         self.check_ast_roundtrip("a[(a:=b)]") | 
 |         self.check_ast_roundtrip("a[(a:=b,c)]") | 
 |         self.check_ast_roundtrip("a[()]") | 
 |         self.check_ast_roundtrip("a[i:j]") | 
 |         self.check_ast_roundtrip("a[:j]") | 
 |         self.check_ast_roundtrip("a[i:]") | 
 |         self.check_ast_roundtrip("a[i:j:k]") | 
 |         self.check_ast_roundtrip("a[:j:k]") | 
 |         self.check_ast_roundtrip("a[i::k]") | 
 |         self.check_ast_roundtrip("a[i:j,]") | 
 |         self.check_ast_roundtrip("a[i:j, k]") | 
 |  | 
 |     def test_invalid_raise(self): | 
 |         self.check_invalid(ast.Raise(exc=None, cause=ast.Name(id="X"))) | 
 |  | 
 |     def test_invalid_fstring_value(self): | 
 |         self.check_invalid( | 
 |             ast.JoinedStr( | 
 |                 values=[ | 
 |                     ast.Name(id="test"), | 
 |                     ast.Constant(value="test") | 
 |                 ] | 
 |             ) | 
 |         ) | 
 |  | 
 |     def test_invalid_fstring_backslash(self): | 
 |         self.check_invalid(ast.FormattedValue(value=ast.Constant(value="\\\\"))) | 
 |  | 
 |     def test_invalid_yield_from(self): | 
 |         self.check_invalid(ast.YieldFrom(value=None)) | 
 |  | 
 |     def test_docstrings(self): | 
 |         docstrings = ( | 
 |             'this ends with double quote"', | 
 |             'this includes a """triple quote"""', | 
 |             '\r', | 
 |             '\\r', | 
 |             '\t', | 
 |             '\\t', | 
 |             '\n', | 
 |             '\\n', | 
 |             '\r\\r\t\\t\n\\n', | 
 |             '""">>> content = \"\"\"blabla\"\"\" <<<"""', | 
 |             r'foo\n\x00', | 
 |             "' \\'\\'\\'\"\"\" \"\"\\'\\' \\'", | 
 |             '🐍⛎𩸽üéş^\\\\X\\\\BB\N{LONG RIGHTWARDS SQUIGGLE ARROW}' | 
 |         ) | 
 |         for docstring in docstrings: | 
 |             # check as Module docstrings for easy testing | 
 |             self.check_ast_roundtrip(f"'''{docstring}'''") | 
 |  | 
 |     def test_constant_tuples(self): | 
 |         self.check_src_roundtrip(ast.Constant(value=(1,), kind=None), "(1,)") | 
 |         self.check_src_roundtrip( | 
 |             ast.Constant(value=(1, 2, 3), kind=None), "(1, 2, 3)" | 
 |         ) | 
 |  | 
 |     def test_function_type(self): | 
 |         for function_type in ( | 
 |             "() -> int", | 
 |             "(int, int) -> int", | 
 |             "(Callable[complex], More[Complex(call.to_typevar())]) -> None" | 
 |         ): | 
 |             self.check_ast_roundtrip(function_type, mode="func_type") | 
 |  | 
 |     def test_type_comments(self): | 
 |         for statement in ( | 
 |             "a = 5 # type:", | 
 |             "a = 5 # type: int", | 
 |             "a = 5 # type: int and more", | 
 |             "def x(): # type: () -> None\n\tpass", | 
 |             "def x(y): # type: (int) -> None and more\n\tpass", | 
 |             "async def x(): # type: () -> None\n\tpass", | 
 |             "async def x(y): # type: (int) -> None and more\n\tpass", | 
 |             "for x in y: # type: int\n\tpass", | 
 |             "async for x in y: # type: int\n\tpass", | 
 |             "with x(): # type: int\n\tpass", | 
 |             "async with x(): # type: int\n\tpass" | 
 |         ): | 
 |             self.check_ast_roundtrip(statement, type_comments=True) | 
 |  | 
 |     def test_type_ignore(self): | 
 |         for statement in ( | 
 |             "a = 5 # type: ignore", | 
 |             "a = 5 # type: ignore and more", | 
 |             "def x(): # type: ignore\n\tpass", | 
 |             "def x(y): # type: ignore and more\n\tpass", | 
 |             "async def x(): # type: ignore\n\tpass", | 
 |             "async def x(y): # type: ignore and more\n\tpass", | 
 |             "for x in y: # type: ignore\n\tpass", | 
 |             "async for x in y: # type: ignore\n\tpass", | 
 |             "with x(): # type: ignore\n\tpass", | 
 |             "async with x(): # type: ignore\n\tpass" | 
 |         ): | 
 |             self.check_ast_roundtrip(statement, type_comments=True) | 
 |  | 
 |  | 
 | class CosmeticTestCase(ASTTestCase): | 
 |     """Test if there are cosmetic issues caused by unnecessary additions""" | 
 |  | 
 |     def test_simple_expressions_parens(self): | 
 |         self.check_src_roundtrip("(a := b)") | 
 |         self.check_src_roundtrip("await x") | 
 |         self.check_src_roundtrip("x if x else y") | 
 |         self.check_src_roundtrip("lambda x: x") | 
 |         self.check_src_roundtrip("1 + 1") | 
 |         self.check_src_roundtrip("1 + 2 / 3") | 
 |         self.check_src_roundtrip("(1 + 2) / 3") | 
 |         self.check_src_roundtrip("(1 + 2) * 3 + 4 * (5 + 2)") | 
 |         self.check_src_roundtrip("(1 + 2) * 3 + 4 * (5 + 2) ** 2") | 
 |         self.check_src_roundtrip("~x") | 
 |         self.check_src_roundtrip("x and y") | 
 |         self.check_src_roundtrip("x and y and z") | 
 |         self.check_src_roundtrip("x and (y and x)") | 
 |         self.check_src_roundtrip("(x and y) and z") | 
 |         self.check_src_roundtrip("(x ** y) ** z ** q") | 
 |         self.check_src_roundtrip("x >> y") | 
 |         self.check_src_roundtrip("x << y") | 
 |         self.check_src_roundtrip("x >> y and x >> z") | 
 |         self.check_src_roundtrip("x + y - z * q ^ t ** k") | 
 |         self.check_src_roundtrip("P * V if P and V else n * R * T") | 
 |         self.check_src_roundtrip("lambda P, V, n: P * V == n * R * T") | 
 |         self.check_src_roundtrip("flag & (other | foo)") | 
 |         self.check_src_roundtrip("not x == y") | 
 |         self.check_src_roundtrip("x == (not y)") | 
 |         self.check_src_roundtrip("yield x") | 
 |         self.check_src_roundtrip("yield from x") | 
 |         self.check_src_roundtrip("call((yield x))") | 
 |         self.check_src_roundtrip("return x + (yield x)") | 
 |  | 
 |     def test_class_bases_and_keywords(self): | 
 |         self.check_src_roundtrip("class X:\n    pass") | 
 |         self.check_src_roundtrip("class X(A):\n    pass") | 
 |         self.check_src_roundtrip("class X(A, B, C, D):\n    pass") | 
 |         self.check_src_roundtrip("class X(x=y):\n    pass") | 
 |         self.check_src_roundtrip("class X(metaclass=z):\n    pass") | 
 |         self.check_src_roundtrip("class X(x=y, z=d):\n    pass") | 
 |         self.check_src_roundtrip("class X(A, x=y):\n    pass") | 
 |         self.check_src_roundtrip("class X(A, **kw):\n    pass") | 
 |         self.check_src_roundtrip("class X(*args):\n    pass") | 
 |         self.check_src_roundtrip("class X(*args, **kwargs):\n    pass") | 
 |  | 
 |     def test_fstrings(self): | 
 |         self.check_src_roundtrip('''f\'\'\'-{f"""*{f"+{f'.{x}.'}+"}*"""}-\'\'\'''') | 
 |         self.check_src_roundtrip('''f"\\u2028{'x'}"''') | 
 |         self.check_src_roundtrip(r"f'{x}\n'") | 
 |         self.check_src_roundtrip('''f''\'{"""\n"""}\\n''\'''') | 
 |         self.check_src_roundtrip('''f''\'{f"""{x}\n"""}\\n''\'''') | 
 |  | 
 |     def test_docstrings(self): | 
 |         docstrings = ( | 
 |             '"""simple doc string"""', | 
 |             '''"""A more complex one | 
 |             with some newlines"""''', | 
 |             '''"""Foo bar baz | 
 |  | 
 |             empty newline"""''', | 
 |             '"""With some \t"""', | 
 |             '"""Foo "bar" baz """', | 
 |             '"""\\r"""', | 
 |             '""""""', | 
 |             '"""\'\'\'"""', | 
 |             '"""\'\'\'\'\'\'"""', | 
 |             '"""🐍⛎𩸽üéş^\\\\X\\\\BB⟿"""', | 
 |             '"""end in single \'quote\'"""', | 
 |             "'''end in double \"quote\"'''", | 
 |             '"""almost end in double "quote"."""', | 
 |         ) | 
 |  | 
 |         for prefix in docstring_prefixes: | 
 |             for docstring in docstrings: | 
 |                 self.check_src_roundtrip(f"{prefix}{docstring}") | 
 |  | 
 |     def test_docstrings_negative_cases(self): | 
 |         # Test some cases that involve strings in the children of the | 
 |         # first node but aren't docstrings to make sure we don't have | 
 |         # False positives. | 
 |         docstrings_negative = ( | 
 |             'a = """false"""', | 
 |             '"""false""" + """unless its optimized"""', | 
 |             '1 + 1\n"""false"""', | 
 |             'f"""no, top level but f-fstring"""' | 
 |         ) | 
 |         for prefix in docstring_prefixes: | 
 |             for negative in docstrings_negative: | 
 |                 # this cases should be result with single quote | 
 |                 # rather then triple quoted docstring | 
 |                 src = f"{prefix}{negative}" | 
 |                 self.check_ast_roundtrip(src) | 
 |                 self.check_src_dont_roundtrip(src) | 
 |  | 
 |     def test_unary_op_factor(self): | 
 |         for prefix in ("+", "-", "~"): | 
 |             self.check_src_roundtrip(f"{prefix}1") | 
 |         for prefix in ("not",): | 
 |             self.check_src_roundtrip(f"{prefix} 1") | 
 |  | 
 |     def test_slices(self): | 
 |         self.check_src_roundtrip("a[()]") | 
 |         self.check_src_roundtrip("a[1]") | 
 |         self.check_src_roundtrip("a[1, 2]") | 
 |         # Note that `a[*a]`, `a[*a,]`, and `a[(*a,)]` all evaluate to the same | 
 |         # thing at runtime and have the same AST, but only `a[*a,]` passes | 
 |         # this test, because that's what `ast.unparse` produces. | 
 |         self.check_src_roundtrip("a[*a,]") | 
 |         self.check_src_roundtrip("a[1, *a]") | 
 |         self.check_src_roundtrip("a[*a, 2]") | 
 |         self.check_src_roundtrip("a[1, *a, 2]") | 
 |         self.check_src_roundtrip("a[*a, *a]") | 
 |         self.check_src_roundtrip("a[1, *a, *a]") | 
 |         self.check_src_roundtrip("a[*a, 1, *a]") | 
 |         self.check_src_roundtrip("a[*a, *a, 1]") | 
 |         self.check_src_roundtrip("a[1, *a, *a, 2]") | 
 |         self.check_src_roundtrip("a[1:2, *a]") | 
 |         self.check_src_roundtrip("a[*a, 1:2]") | 
 |  | 
 |     def test_lambda_parameters(self): | 
 |         self.check_src_roundtrip("lambda: something") | 
 |         self.check_src_roundtrip("four = lambda: 2 + 2") | 
 |         self.check_src_roundtrip("lambda x: x * 2") | 
 |         self.check_src_roundtrip("square = lambda n: n ** 2") | 
 |         self.check_src_roundtrip("lambda x, y: x + y") | 
 |         self.check_src_roundtrip("add = lambda x, y: x + y") | 
 |         self.check_src_roundtrip("lambda x, y, /, z, q, *, u: None") | 
 |         self.check_src_roundtrip("lambda x, *y, **z: None") | 
 |  | 
 |     def test_star_expr_assign_target(self): | 
 |         for source_type, source in [ | 
 |             ("single assignment", "{target} = foo"), | 
 |             ("multiple assignment", "{target} = {target} = bar"), | 
 |             ("for loop", "for {target} in foo:\n    pass"), | 
 |             ("async for loop", "async for {target} in foo:\n    pass") | 
 |         ]: | 
 |             for target in [ | 
 |                 "a", | 
 |                 "a,", | 
 |                 "a, b", | 
 |                 "a, *b, c", | 
 |                 "a, (b, c), d", | 
 |                 "a, (b, c, d), *e", | 
 |                 "a, (b, *c, d), e", | 
 |                 "a, (b, *c, (d, e), f), g", | 
 |                 "[a]", | 
 |                 "[a, b]", | 
 |                 "[a, *b, c]", | 
 |                 "[a, [b, c], d]", | 
 |                 "[a, [b, c, d], *e]", | 
 |                 "[a, [b, *c, d], e]", | 
 |                 "[a, [b, *c, [d, e], f], g]", | 
 |                 "a, [b, c], d", | 
 |                 "[a, b, (c, d), (e, f)]", | 
 |                 "a, b, [*c], d, e" | 
 |             ]: | 
 |                 with self.subTest(source_type=source_type, target=target): | 
 |                     self.check_src_roundtrip(source.format(target=target)) | 
 |  | 
 |     def test_star_expr_assign_target_multiple(self): | 
 |         self.check_src_roundtrip("() = []") | 
 |         self.check_src_roundtrip("[] = ()") | 
 |         self.check_src_roundtrip("() = [a] = c, = [d] = e, f = () = g = h") | 
 |         self.check_src_roundtrip("a = b = c = d") | 
 |         self.check_src_roundtrip("a, b = c, d = e, f = g") | 
 |         self.check_src_roundtrip("[a, b] = [c, d] = [e, f] = g") | 
 |         self.check_src_roundtrip("a, b = [c, d] = e, f = g") | 
 |  | 
 |  | 
 |  | 
 | class DirectoryTestCase(ASTTestCase): | 
 |     """Test roundtrip behaviour on all files in Lib and Lib/test.""" | 
 |  | 
 |     lib_dir = pathlib.Path(__file__).parent / ".." | 
 |     test_directories = (lib_dir, lib_dir / "test") | 
 |     run_always_files = {"test_grammar.py", "test_syntax.py", "test_compile.py", | 
 |                         "test_ast.py", "test_asdl_parser.py", "test_fstring.py", | 
 |                         "test_patma.py"} | 
 |  | 
 |     _files_to_test = None | 
 |  | 
 |     @classmethod | 
 |     def files_to_test(cls): | 
 |  | 
 |         if cls._files_to_test is not None: | 
 |             return cls._files_to_test | 
 |  | 
 |         items = [ | 
 |             item.resolve() | 
 |             for directory in cls.test_directories | 
 |             for item in directory.glob("*.py") | 
 |             if not item.name.startswith("bad") | 
 |         ] | 
 |  | 
 |         # Test limited subset of files unless the 'cpu' resource is specified. | 
 |         if not test.support.is_resource_enabled("cpu"): | 
 |  | 
 |             tests_to_run_always = {item for item in items if | 
 |                                    item.name in cls.run_always_files} | 
 |  | 
 |             items = set(random.sample(items, 10)) | 
 |  | 
 |             # Make sure that at least tests that heavily use grammar features are | 
 |             # always considered in order to reduce the chance of missing something. | 
 |             items = list(items | tests_to_run_always) | 
 |  | 
 |         # bpo-31174: Store the names sample to always test the same files. | 
 |         # It prevents false alarms when hunting reference leaks. | 
 |         cls._files_to_test = items | 
 |  | 
 |         return items | 
 |  | 
 |     def test_files(self): | 
 |         for item in self.files_to_test(): | 
 |             if test.support.verbose: | 
 |                 print(f"Testing {item.absolute()}") | 
 |  | 
 |             with self.subTest(filename=item): | 
 |                 source = read_pyfile(item) | 
 |                 self.check_ast_roundtrip(source) | 
 |  | 
 |  | 
 | if __name__ == "__main__": | 
 |     unittest.main() |