import unittest import test.support import io import os import tokenize import ast import unparse def read_pyfile(filename): """Read and return the contents of a Python source file (as a string), taking into account the file encoding.""" with open(filename, "rb") as pyfile: encoding = tokenize.detect_encoding(pyfile.readline)[0] with open(filename, "r", encoding=encoding) as pyfile: source = pyfile.read() return source 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 """ class ASTTestCase(unittest.TestCase): def assertASTEqual(self, ast1, ast2): self.assertEqual(ast.dump(ast1), ast.dump(ast2)) def check_roundtrip(self, code1, filename="internal"): ast1 = compile(code1, filename, "exec", ast.PyCF_ONLY_AST) unparse_buffer = io.StringIO() unparse.Unparser(ast1, unparse_buffer) code2 = unparse_buffer.getvalue() ast2 = compile(code2, filename, "exec", ast.PyCF_ONLY_AST) self.assertASTEqual(ast1, ast2) class UnparseTestCase(ASTTestCase): # Tests for specific bugs found in earlier versions of unparse def test_del_statement(self): self.check_roundtrip("del x, y, z") def test_shifts(self): self.check_roundtrip("45 << 2") self.check_roundtrip("13 >> 7") def test_for_else(self): self.check_roundtrip(for_else) def test_while_else(self): self.check_roundtrip(while_else) def test_unary_parens(self): self.check_roundtrip("(-1)**7") self.check_roundtrip("(-1.)**8") self.check_roundtrip("(-1j)**6") self.check_roundtrip("not True or False") self.check_roundtrip("True or not False") def test_integer_parens(self): self.check_roundtrip("3 .__abs__()") def test_huge_float(self): self.check_roundtrip("1e1000") self.check_roundtrip("-1e1000") self.check_roundtrip("1e1000j") self.check_roundtrip("-1e1000j") def test_min_int(self): self.check_roundtrip(str(-2**31)) self.check_roundtrip(str(-2**63)) def test_imaginary_literals(self): self.check_roundtrip("7j") self.check_roundtrip("-7j") self.check_roundtrip("0j") self.check_roundtrip("-0j") def test_lambda_parentheses(self): self.check_roundtrip("(lambda: int)()") def test_chained_comparisons(self): self.check_roundtrip("1 < 4 <= 5") self.check_roundtrip("a is b is c is not d") def test_function_arguments(self): self.check_roundtrip("def f(): pass") self.check_roundtrip("def f(a): pass") self.check_roundtrip("def f(b = 2): pass") self.check_roundtrip("def f(a, b): pass") self.check_roundtrip("def f(a, b = 2): pass") self.check_roundtrip("def f(a = 5, b = 2): pass") self.check_roundtrip("def f(*, a = 1, b = 2): pass") self.check_roundtrip("def f(*, a = 1, b): pass") self.check_roundtrip("def f(*, a, b = 2): pass") self.check_roundtrip("def f(a, b = None, *, c, **kwds): pass") self.check_roundtrip("def f(a=2, *args, c=5, d, **kwds): pass") self.check_roundtrip("def f(*args, **kwargs): pass") def test_relative_import(self): self.check_roundtrip(relative_import) def test_nonlocal(self): self.check_roundtrip(nonlocal_ex) def test_raise_from(self): self.check_roundtrip(raise_from) def test_bytes(self): self.check_roundtrip("b'123'") def test_annotations(self): self.check_roundtrip("def f(a : int): pass") self.check_roundtrip("def f(a: int = 5): pass") self.check_roundtrip("def f(*args: [int]): pass") self.check_roundtrip("def f(**kwargs: dict): pass") self.check_roundtrip("def f() -> None: pass") def test_set_literal(self): self.check_roundtrip("{'a', 'b', 'c'}") def test_set_comprehension(self): self.check_roundtrip("{x for x in range(5)}") def test_dict_comprehension(self): self.check_roundtrip("{x: x*x for x in range(10)}") def test_class_decorators(self): self.check_roundtrip(class_decorator) def test_class_definition(self): self.check_roundtrip("class A(metaclass=type, *[], **{}): pass") def test_elifs(self): self.check_roundtrip(elif1) self.check_roundtrip(elif2) def test_try_except_finally(self): self.check_roundtrip(try_except_finally) def test_starred_assignment(self): self.check_roundtrip("a, *b, c = seq") self.check_roundtrip("a, (*b, c) = seq") self.check_roundtrip("a, *b[0], c = seq") self.check_roundtrip("a, *(b, c) = seq") class DirectoryTestCase(ASTTestCase): """Test roundtrip behaviour on all files in Lib and Lib/test.""" # test directories, relative to the root of the distribution test_directories = 'Lib', os.path.join('Lib', 'test') def test_files(self): # get names of files to test dist_dir = os.path.join(os.path.dirname(__file__), os.pardir, os.pardir) names = [] for d in self.test_directories: test_dir = os.path.join(dist_dir, d) for n in os.listdir(test_dir): if n.endswith('.py') and not n.startswith('bad'): names.append(os.path.join(test_dir, n)) for filename in names: if test.support.verbose: print('Testing %s' % filename) source = read_pyfile(filename) self.check_roundtrip(source) def test_main(): test.support.run_unittest(UnparseTestCase, DirectoryTestCase) if __name__ == '__main__': test_main()