"""Tests for ast.unparse.""" import unittest import test.support import pathlib import random import tokenize import ast from test.support.ast_helper import ASTTestMixin 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(ASTTestMixin, unittest.TestCase): 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_fstrings_pep701(self): self.check_ast_roundtrip('f" something { my_dict["key"] } something else "') self.check_ast_roundtrip('f"{f"{f"{f"{f"{f"{1+1}"}"}"}"}"}"') 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", ctx=ast.Load()))) def test_invalid_fstring_value(self): self.check_invalid( ast.JoinedStr( values=[ ast.Name(id="test", ctx=ast.Load()), ast.Constant(value="test") ] ) ) def test_fstring_backslash(self): # valid since Python 3.12 self.assertEqual(ast.unparse( ast.FormattedValue( value=ast.Constant(value="\\\\"), conversion=-1, format_spec=None, ) ), "{'\\\\\\\\'}") def test_invalid_yield_from(self): self.check_invalid(ast.YieldFrom(value=None)) def test_import_from_level_none(self): tree = ast.ImportFrom(module='mod', names=[ast.alias(name='x')]) self.assertEqual(ast.unparse(tree), "from mod import x") tree = ast.ImportFrom(module='mod', names=[ast.alias(name='x')], level=None) self.assertEqual(ast.unparse(tree), "from mod import x") 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") def test_multiquote_joined_string(self): self.check_ast_roundtrip("f\"'''{1}\\\"\\\"\\\"\" ") self.check_ast_roundtrip("""f"'''{1}""\\"" """) self.check_ast_roundtrip("""f'""\"{1}''' """) self.check_ast_roundtrip("""f'""\"{1}""\\"' """) self.check_ast_roundtrip("""f"'''{"\\n"}""\\"" """) self.check_ast_roundtrip("""f'""\"{"\\n"}''' """) self.check_ast_roundtrip("""f'""\"{"\\n"}""\\"' """) self.check_ast_roundtrip("""f'''""\"''\\'{"\\n"}''' """) self.check_ast_roundtrip("""f'''""\"''\\'{"\\n\\"'"}''' """) self.check_ast_roundtrip("""f'''""\"''\\'{""\"\\n\\"'''""\" '''\\n'''}''' """) def test_backslash_in_format_spec(self): import re msg = re.escape("invalid escape sequence '\\ '") with self.assertWarnsRegex(SyntaxWarning, msg): self.check_ast_roundtrip("""f"{x:\\ }" """) self.check_ast_roundtrip("""f"{x:\\n}" """) self.check_ast_roundtrip("""f"{x:\\\\ }" """) with self.assertWarnsRegex(SyntaxWarning, msg): self.check_ast_roundtrip("""f"{x:\\\\\\ }" """) self.check_ast_roundtrip("""f"{x:\\\\\\n}" """) self.check_ast_roundtrip("""f"{x:\\\\\\\\ }" """) def test_quote_in_format_spec(self): self.check_ast_roundtrip("""f"{x:'}" """) self.check_ast_roundtrip("""f"{x:\\'}" """) self.check_ast_roundtrip("""f"{x:\\\\'}" """) self.check_ast_roundtrip("""f'\\'{x:"}' """) self.check_ast_roundtrip("""f'\\'{x:\\"}' """) self.check_ast_roundtrip("""f'\\'{x:\\\\"}' """) 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", ctx=ast.Load()))], ) 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.""" 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", "test_type_alias.py", "test_type_params.py", "test_tokenize.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()