import ast
import _peg_parser as peg_parser
import unittest
from typing import Any, Union, Iterable, Tuple
from textwrap import dedent
from test import support
TEST_CASES = [
('annotated_assignment', 'x: int = 42'),
('annotated_assignment_with_tuple', 'x: tuple = 1, 2'),
('annotated_assignment_with_parens', '(paren): int = 3+2'),
('annotated_assignment_with_yield', 'x: int = yield 42'),
('annotated_no_assignment', 'x: int'),
('annotation_with_multiple_parens', '((parens)): int'),
('annotation_with_parens', '(parens): int'),
('annotated_assignment_with_attr', 'a.b: int'),
('annotated_assignment_with_subscript', 'a[b]: int'),
('annotated_assignment_with_attr_and_parens', '(a.b): int'),
('annotated_assignment_with_subscript_and_parens', '(a[b]): int'),
('assert', 'assert a'),
('assert_message', 'assert a, b'),
('assignment_false', 'a = False'),
('assignment_none', 'a = None'),
('assignment_true', 'a = True'),
('assignment_paren', '(a) = 42'),
('assignment_paren_multiple', '(a, b) = (0, 1)'),
('asyncfor',
'''
async for i in a:
pass
'''),
('attribute_call', 'a.b()'),
('attribute_multiple_names', 'abcd.efg.hij'),
('attribute_simple', 'a.b'),
('attributes_subscript', 'a.b[0]'),
('augmented_assignment', 'x += 42'),
('augmented_assignment_attribute', 'a.b.c += 42'),
('augmented_assignment_paren', '(x) += 42'),
('augmented_assignment_paren_subscript', '(x[0]) -= 42'),
('binop_add', '1 + 1'),
('binop_add_multiple', '1 + 1 + 1 + 1'),
('binop_all', '1 + 2 * 5 + 3 ** 2 - -3'),
('binop_boolop_comp', '1 + 1 == 2 or 1 + 1 == 3 and not b'),
('boolop_or', 'a or b'),
('boolop_or_multiple', 'a or b or c'),
('class_def_bases',
'''
class C(A, B):
pass
'''),
('class_def_decorators',
'''
@a
class C:
pass
'''),
('class_def_decorator_with_expression',
'''
@lambda x: 42
class C:
pass
'''),
('class_def_decorator_with_expression_and_walrus',
'''
@x:=lambda x: 42
class C:
pass
'''),
('class_def_keywords',
'''
class C(keyword=a+b, **c):
pass
'''),
('class_def_mixed',
'''
class C(A, B, keyword=0, **a):
pass
'''),
('class_def_simple',
'''
class C:
pass
'''),
('class_def_starred_and_kwarg',
'''
class C(A, B, *x, **y):
pass
'''),
('class_def_starred_in_kwargs',
'''
class C(A, x=2, *[B, C], y=3):
pass
'''),
('call_attribute', 'f().b'),
('call_genexp', 'f(i for i in a)'),
('call_mixed_args', 'f(a, b, *c, **d)'),
('call_mixed_args_named', 'f(a, b, *c, d=4, **v)'),
('call_one_arg', 'f(a)'),
('call_posarg_genexp', 'f(a, (i for i in a))'),
('call_simple', 'f()'),
('call_subscript', 'f()[0]'),
('comp', 'a == b'),
('comp_multiple', 'a == b == c'),
('comp_paren_end', 'a == (b-1)'),
('comp_paren_start', '(a-1) == b'),
('decorator',
'''
@a
def f():
pass
'''),
('decorator_async',
'''
@a
async def d():
pass
'''),
('decorator_with_expression',
'''
@lambda x: 42
def f():
pass
'''),
('decorator_with_expression_and_walrus',
'''
@x:=lambda x: 42
def f():
pass
'''),
('del_attribute', 'del a.b'),
('del_call_attribute', 'del a().c'),
('del_call_genexp_attribute', 'del a(i for i in b).c'),
('del_empty', 'del()'),
('del_list', 'del a, [b, c]'),
('del_mixed', 'del a[0].b().c'),
('del_multiple', 'del a, b'),
('del_multiple_calls_attribute', 'del a()().b'),
('del_paren', 'del(a,b)'),
('del_paren_single_target', 'del(a)'),
('del_subscript_attribute', 'del a[0].b'),
('del_tuple', 'del a, (b, c)'),
('delete', 'del a'),
('dict',
'''
{
a: 1,
b: 2,
c: 3
}
'''),
('dict_comp', '{x:1 for x in a}'),
('dict_comp_if', '{x:1+2 for x in a if b}'),
('dict_empty', '{}'),
('empty_line_after_linecont',
r'''
pass
\
pass
'''),
('for',
'''
for i in a:
pass
'''),
('for_else',
'''
for i in a:
pass
else:
pass
'''),
('for_star_target_in_paren', 'for (a) in b: pass'),
('for_star_targets_attribute', 'for a.b in c: pass'),
('for_star_targets_call_attribute', 'for a().c in b: pass'),
('for_star_targets_empty', 'for () in a: pass'),
('for_star_targets_mixed', 'for a[0].b().c in d: pass'),
('for_star_targets_mixed_starred',
'''
for a, *b, (c, d) in e:
pass
'''),
('for_star_targets_multiple', 'for a, b in c: pass'),
('for_star_targets_nested_starred', 'for *[*a] in b: pass'),
('for_star_targets_starred', 'for *a in b: pass'),
('for_star_targets_subscript_attribute', 'for a[0].b in c: pass'),
('for_star_targets_trailing_comma',
'''
for a, (b, c), in d:
pass
'''),
('for_star_targets_tuple', 'for a, (b, c) in d: pass'),
('for_underscore',
'''
for _ in a:
pass
'''),
('function_return_type',
'''
def f() -> Any:
pass
'''),
('f-string_slice', "f'{x[2]}'"),
('f-string_slice_upper', "f'{x[2:3]}'"),
('f-string_slice_step', "f'{x[2:3:-2]}'"),
('f-string_constant', "f'{42}'"),
('f-string_boolop', "f'{x and y}'"),
('f-string_named_expr', "f'{(x:=42)}'"),
('f-string_binop', "f'{x+y}'"),
('f-string_unaryop', "f'{not x}'"),
('f-string_lambda', "f'{(lambda x, /, y, y2=42 , *z, k1, k2=34, **k3: 42)}'"),
('f-string_lambda_call', "f'{(lambda: 2)(2)}'"),
('f-string_ifexpr', "f'{x if y else z}'"),
('f-string_dict', "f'{ {2:34, 3:34} }'"),
('f-string_set', "f'{ {2,-45} }'"),
('f-string_list', "f'{ [2,-45] }'"),
('f-string_tuple', "f'{ (2,-45) }'"),
('f-string_listcomp', "f'{[x for x in y if z]}'"),
('f-string_setcomp', "f'{ {x for x in y if z} }'"),
('f-string_dictcomp', "f'{ {x:x for x in y if z} }'"),
('f-string_genexpr', "f'{ (x for x in y if z) }'"),
('f-string_yield', "f'{ (yield x) }'"),
('f-string_yieldfrom', "f'{ (yield from x) }'"),
('f-string_await', "f'{ await x }'"),
('f-string_compare', "f'{ x == y }'"),
('f-string_call', "f'{ f(x,y,z) }'"),
('f-string_attribute', "f'{ f.x.y.z }'"),
('f-string_starred', "f'{ *x, }'"),
('f-string_doublestarred', "f'{ {**x} }'"),
('f-string_escape_brace', "f'{{Escape'"),
('f-string_escape_closing_brace', "f'Escape}}'"),
('f-string_multiline',
"""
f'''
{hello}
'''
"""),
('f-string_multiline_in_expr',
"""
f'''
{
hello
}
'''
"""),
('f-string_multiline_in_call',
"""
f'''
{f(
a, b, c
)}
'''
"""),
('global', 'global a, b'),
('group', '(yield a)'),
('if_elif',
'''
if a:
pass
elif b:
pass
'''),
('if_elif_elif',
'''
if a:
pass
elif b:
pass
elif c:
pass
'''),
('if_elif_else',
'''
if a:
pass
elif b:
pass
else:
pass
'''),
('if_else',
'''
if a:
pass
else:
pass
'''),
('if_simple', 'if a: pass'),
('import', 'import a'),
('import_alias', 'import a as b'),
('import_dotted', 'import a.b'),
('import_dotted_alias', 'import a.b as c'),
('import_dotted_multichar', 'import ab.cd'),
('import_from', 'from a import b'),
('import_from_alias', 'from a import b as c'),
('import_from_dotted', 'from a.b import c'),
('import_from_dotted_alias', 'from a.b import c as d'),
('import_from_multiple_aliases', 'from a import b as c, d as e'),
('import_from_one_dot', 'from .a import b'),
('import_from_one_dot_alias', 'from .a import b as c'),
('import_from_star', 'from a import *'),
('import_from_three_dots', 'from ...a import b'),
('import_from_trailing_comma', 'from a import (b,)'),
('kwarg',
'''
def f(**a):
pass
'''),
('kwonly_args',
'''
def f(*, a, b):
pass
'''),
('kwonly_args_with_default',
'''
def f(*, a=2, b):
pass
'''),
('lambda_kwarg', 'lambda **a: 42'),
('lambda_kwonly_args', 'lambda *, a, b: 42'),
('lambda_kwonly_args_with_default', 'lambda *, a=2, b: 42'),
('lambda_mixed_args', 'lambda a, /, b, *, c: 42'),
('lambda_mixed_args_with_default', 'lambda a, b=2, /, c=3, *e, f, **g: 42'),
('lambda_no_args', 'lambda: 42'),
('lambda_pos_args', 'lambda a,b: 42'),
('lambda_pos_args_with_default', 'lambda a, b=2: 42'),
('lambda_pos_only_args', 'lambda a, /: 42'),
('lambda_pos_only_args_with_default', 'lambda a=0, /: 42'),
('lambda_pos_posonly_args', 'lambda a, b, /, c, d: 42'),
('lambda_pos_posonly_args_with_default', 'lambda a, b=0, /, c=2: 42'),
('lambda_vararg', 'lambda *a: 42'),
('lambda_vararg_kwonly_args', 'lambda *a, b: 42'),
('list', '[1, 2, a]'),
('list_comp', '[i for i in a]'),
('list_comp_if', '[i for i in a if b]'),
('list_trailing_comma', '[1+2, a, 3+4,]'),
('mixed_args',
'''
def f(a, /, b, *, c):
pass
'''),
('mixed_args_with_default',
'''
def f(a, b=2, /, c=3, *e, f, **g):
pass
'''),
('multipart_string_bytes', 'b"Hola" b"Hello" b"Bye"'),
('multipart_string_triple', '"""Something here""" "and now"'),
('multipart_string_different_prefixes', 'u"Something" "Other thing" r"last thing"'),
('multiple_assignments', 'x = y = z = 42'),
('multiple_assignments_with_yield', 'x = y = z = yield 42'),
('multiple_pass',
'''
pass; pass
pass
'''),
('namedexpr', '(x := [1, 2, 3])'),
('namedexpr_false', '(x := False)'),
('namedexpr_none', '(x := None)'),
('namedexpr_true', '(x := True)'),
('nonlocal', 'nonlocal a, b'),
('number_complex', '-2.234+1j'),
('number_float', '-34.2333'),
('number_imaginary_literal', '1.1234j'),
('number_integer', '-234'),
('number_underscores', '1_234_567'),
('pass', 'pass'),
('pos_args',
'''
def f(a, b):
pass
'''),
('pos_args_with_default',
'''
def f(a, b=2):
pass
'''),
('pos_only_args',
'''
def f(a, /):
pass
'''),
('pos_only_args_with_default',
'''
def f(a=0, /):
pass
'''),
('pos_posonly_args',
'''
def f(a, b, /, c, d):
pass
'''),
('pos_posonly_args_with_default',
'''
def f(a, b=0, /, c=2):
pass
'''),
('primary_mixed', 'a.b.c().d[0]'),
('raise', 'raise'),
('raise_ellipsis', 'raise ...'),
('raise_expr', 'raise a'),
('raise_from', 'raise a from b'),
('return', 'return'),
('return_expr', 'return a'),
('set', '{1, 2+4, 3+5}'),
('set_comp', '{i for i in a}'),
('set_trailing_comma', '{1, 2, 3,}'),
('simple_assignment', 'x = 42'),
('simple_assignment_with_yield', 'x = yield 42'),
('string_bytes', 'b"hello"'),
('string_concatenation_bytes', 'b"hello" b"world"'),
('string_concatenation_simple', '"abcd" "efgh"'),
('string_format_simple', 'f"hello"'),
('string_format_with_formatted_value', 'f"hello {world}"'),
('string_simple', '"hello"'),
('string_unicode', 'u"hello"'),
('subscript_attribute', 'a[0].b'),
('subscript_call', 'a[b]()'),
('subscript_multiple_slices', 'a[0:a:2, 1]'),
('subscript_simple', 'a[0]'),
('subscript_single_element_tuple', 'a[0,]'),
('subscript_trailing_comma', 'a[0, 1, 2,]'),
('subscript_tuple', 'a[0, 1, 2]'),
('subscript_whole_slice', 'a[0+1:b:c]'),
('try_except',
'''
try:
pass
except:
pass
'''),
('try_except_else',
'''
try:
pass
except:
pass
else:
pass
'''),
('try_except_else_finally',
'''
try:
pass
except:
pass
else:
pass
finally:
pass
'''),
('try_except_expr',
'''
try:
pass
except a:
pass
'''),
('try_except_expr_target',
'''
try:
pass
except a as b:
pass
'''),
('try_except_finally',
'''
try:
pass
except:
pass
finally:
pass
'''),
('try_finally',
'''
try:
pass
finally:
pass
'''),
('unpacking_binop', '[*([1, 2, 3] + [3, 4, 5])]'),
('unpacking_call', '[*b()]'),
('unpacking_compare', '[*(x < y)]'),
('unpacking_constant', '[*3]'),
('unpacking_dict', '[*{1: 2, 3: 4}]'),
('unpacking_dict_comprehension', '[*{x:y for x,y in z}]'),
('unpacking_ifexpr', '[*([1, 2, 3] if x else y)]'),
('unpacking_list', '[*[1,2,3]]'),
('unpacking_list_comprehension', '[*[x for x in y]]'),
('unpacking_namedexpr', '[*(x:=[1, 2, 3])]'),
('unpacking_set', '[*{1,2,3}]'),
('unpacking_set_comprehension', '[*{x for x in y}]'),
('unpacking_string', '[*"myvalue"]'),
('unpacking_tuple', '[*(1,2,3)]'),
('unpacking_unaryop', '[*(not [1, 2, 3])]'),
('unpacking_yield', '[*(yield 42)]'),
('unpacking_yieldfrom', '[*(yield from x)]'),
('tuple', '(1, 2, 3)'),
('vararg',
'''
def f(*a):
pass
'''),
('vararg_kwonly_args',
'''
def f(*a, b):
pass
'''),
('while',
'''
while a:
pass
'''),
('while_else',
'''
while a:
pass
else:
pass
'''),
('with',
'''
with a:
pass
'''),
('with_as',
'''
with a as b:
pass
'''),
('with_as_paren',
'''
with a as (b):
pass
'''),
('with_as_empty', 'with a as (): pass'),
('with_list_recursive',
'''
with a as [x, [y, z]]:
pass
'''),
('with_tuple_recursive',
'''
with a as ((x, y), z):
pass
'''),
('with_tuple_target',
'''
with a as (x, y):
pass
'''),
('with_list_target',
'''
with a as [x, y]:
pass
'''),
('yield', 'yield'),
('yield_expr', 'yield a'),
('yield_from', 'yield from a'),
]
FAIL_TEST_CASES = [
("annotation_multiple_targets", "(a, b): int = 42"),
("annotation_nested_tuple", "((a, b)): int"),
("annotation_list", "[a]: int"),
("annotation_lambda", "lambda: int = 42"),
("annotation_tuple", "(a,): int"),
("annotation_tuple_without_paren", "a,: int"),
("assignment_keyword", "a = if"),
("augmented_assignment_list", "[a, b] += 1"),
("augmented_assignment_tuple", "a, b += 1"),
("augmented_assignment_tuple_paren", "(a, b) += (1, 2)"),
("comprehension_lambda", "(a for a in lambda: b)"),
("comprehension_else", "(a for a in b if c else d"),
("del_call", "del a()"),
("del_call_genexp", "del a(i for i in b)"),
("del_subscript_call", "del a[b]()"),
("del_attribute_call", "del a.b()"),
("del_mixed_call", "del a[0].b().c.d()"),
("for_star_targets_call", "for a() in b: pass"),
("for_star_targets_subscript_call", "for a[b]() in c: pass"),
("for_star_targets_attribute_call", "for a.b() in c: pass"),
("for_star_targets_mixed_call", "for a[0].b().c.d() in e: pass"),
("for_star_targets_in", "for a, in in b: pass"),
("f-string_assignment", "f'{x = 42}'"),
("f-string_empty", "f'{}'"),
("f-string_function_def", "f'{def f(): pass}'"),
("f-string_lambda", "f'{lambda x: 42}'"),
("f-string_singe_brace", "f'{'"),
("f-string_single_closing_brace", "f'}'"),
("from_import_invalid", "from import import a"),
("from_import_trailing_comma", "from a import b,"),
("import_non_ascii_syntax_error", "import ä £"),
# This test case checks error paths involving tokens with uninitialized
# values of col_offset and end_col_offset.
("invalid indentation",
"""
def f():
a
a
"""),
("not_terminated_string", "a = 'example"),
("try_except_attribute_target",
"""
try:
pass
except Exception as a.b:
pass
"""),
("try_except_subscript_target",
"""
try:
pass
except Exception as a[0]:
pass
"""),
]
FAIL_SPECIALIZED_MESSAGE_CASES = [
("f(x, y, z=1, **b, *a", "iterable argument unpacking follows keyword argument unpacking"),
("f(x, y=1, *z, **a, b", "positional argument follows keyword argument unpacking"),
("f(x, y, z=1, a=2, b", "positional argument follows keyword argument"),
("True = 1", "cannot assign to True"),
("a() = 1", "cannot assign to function call"),
("(a, b): int", "only single target (not tuple) can be annotated"),
("[a, b]: int", "only single target (not list) can be annotated"),
("a(): int", "illegal target for annotation"),
("1 += 1", "'literal' is an illegal expression for augmented assignment"),
("pass\n pass", "unexpected indent"),
("def f():\npass", "expected an indented block"),
("def f(*): pass", "named arguments must follow bare *"),
("def f(*,): pass", "named arguments must follow bare *"),
("def f(*, **a): pass", "named arguments must follow bare *"),
("lambda *: pass", "named arguments must follow bare *"),
("lambda *,: pass", "named arguments must follow bare *"),
("lambda *, **a: pass", "named arguments must follow bare *"),
("f(g()=2", "expression cannot contain assignment, perhaps you meant \"==\"?"),
("f(a, b, *c, d.e=2", "expression cannot contain assignment, perhaps you meant \"==\"?"),
("f(*a, **b, c=0, d[1]=3)", "expression cannot contain assignment, perhaps you meant \"==\"?"),
]
GOOD_BUT_FAIL_TEST_CASES = [
('string_concatenation_format', 'f"{hello} world" f"again {and_again}"'),
('string_concatenation_multiple',
'''
f"hello" f"{world} again" f"and_again"
'''),
('f-string_multiline_comp',
"""
f'''
{(i for i in a
if b)}
'''
"""),
]
FSTRINGS_TRACEBACKS = {
'multiline_fstrings_same_line_with_brace': (
"""
f'''
{a$b}
'''
""",
'(a$b)\n',
),
'multiline_fstring_brace_on_next_line': (
"""
f'''
{a$b
}'''
""",
'(a$b\n',
),
'multiline_fstring_brace_on_previous_line': (
"""
f'''
{
a$b}'''
""",
'a$b)\n',
),
}
EXPRESSIONS_TEST_CASES = [
("expression_add", "1+1"),
("expression_add_2", "a+b"),
("expression_call", "f(a, b=2, **kw)"),
("expression_tuple", "1, 2, 3"),
("expression_tuple_one_value", "1,")
]
def cleanup_source(source: Any) -> str:
if isinstance(source, str):
result = dedent(source)
elif not isinstance(source, (list, tuple)):
result = "\n".join(source)
else:
raise TypeError(f"Invalid type for test source: {source}")
return result
def prepare_test_cases(
test_cases: Iterable[Tuple[str, Union[str, Iterable[str]]]]
) -> Tuple[Iterable[str], Iterable[str]]:
test_ids, _test_sources = zip(*test_cases)
test_sources = list(_test_sources)
for index, source in enumerate(test_sources):
result = cleanup_source(source)
test_sources[index] = result
return test_ids, test_sources
TEST_IDS, TEST_SOURCES = prepare_test_cases(TEST_CASES)
GOOD_BUT_FAIL_TEST_IDS, GOOD_BUT_FAIL_SOURCES = prepare_test_cases(
GOOD_BUT_FAIL_TEST_CASES
)
FAIL_TEST_IDS, FAIL_SOURCES = prepare_test_cases(FAIL_TEST_CASES)
EXPRESSIONS_TEST_IDS, EXPRESSIONS_TEST_SOURCES = prepare_test_cases(
EXPRESSIONS_TEST_CASES
)
class ASTGenerationTest(unittest.TestCase):
def test_correct_ast_generation_on_source_files(self) -> None:
self.maxDiff = None
for source in TEST_SOURCES:
actual_ast = peg_parser.parse_string(source)
expected_ast = peg_parser.parse_string(source, oldparser=True)
self.assertEqual(
ast.dump(actual_ast, include_attributes=True),
ast.dump(expected_ast, include_attributes=True),
f"Wrong AST generation for source: {source}",
)
def test_incorrect_ast_generation_on_source_files(self) -> None:
for source in FAIL_SOURCES:
with self.assertRaises(SyntaxError, msg=f"Parsing {source} did not raise an exception"):
peg_parser.parse_string(source)
def test_incorrect_ast_generation_with_specialized_errors(self) -> None:
for source, error_text in FAIL_SPECIALIZED_MESSAGE_CASES:
exc = IndentationError if "indent" in error_text else SyntaxError
with self.assertRaises(exc) as se:
peg_parser.parse_string(source)
self.assertTrue(
error_text in se.exception.msg,
f"Actual error message does not match expexted for {source}"
)
@unittest.expectedFailure
def test_correct_but_known_to_fail_ast_generation_on_source_files(self) -> None:
for source in GOOD_BUT_FAIL_SOURCES:
actual_ast = peg_parser.parse_string(source)
expected_ast = peg_parser.parse_string(source, oldparser=True)
self.assertEqual(
ast.dump(actual_ast, include_attributes=True),
ast.dump(expected_ast, include_attributes=True),
f"Wrong AST generation for source: {source}",
)
def test_correct_ast_generation_without_pos_info(self) -> None:
for source in GOOD_BUT_FAIL_SOURCES:
actual_ast = peg_parser.parse_string(source)
expected_ast = peg_parser.parse_string(source, oldparser=True)
self.assertEqual(
ast.dump(actual_ast),
ast.dump(expected_ast),
f"Wrong AST generation for source: {source}",
)
def test_fstring_parse_error_tracebacks(self) -> None:
for source, error_text in FSTRINGS_TRACEBACKS.values():
with self.assertRaises(SyntaxError) as se:
peg_parser.parse_string(dedent(source))
self.assertEqual(error_text, se.exception.text)
def test_correct_ast_generatrion_eval(self) -> None:
for source in EXPRESSIONS_TEST_SOURCES:
actual_ast = peg_parser.parse_string(source, mode='eval')
expected_ast = peg_parser.parse_string(source, mode='eval', oldparser=True)
self.assertEqual(
ast.dump(actual_ast, include_attributes=True),
ast.dump(expected_ast, include_attributes=True),
f"Wrong AST generation for source: {source}",
)
def test_tokenizer_errors_are_propagated(self) -> None:
n=201
with self.assertRaisesRegex(SyntaxError, "too many nested parentheses"):
peg_parser.parse_string(n*'(' + ')'*n)