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import sys

import os.path

import shutil

import unittest

import pytest

import warnings

from tests import test_utils

from semmle.python.parser.dump_ast import old_parser, AstDumper, StdoutLogger

from semmle.python.parser.tsg_parser import parse as new_parser

import subprocess

class ParserTest(unittest.TestCase):

def __init__(self, name):

super(ParserTest, self).__init__(name)

self.test_folder = os.path.join(os.path.dirname(__file__), "parser")

self.maxDiff = None

@pytest.fixture(autouse=True)

def capsys(self, capsys):

self.capsys = capsys

def compare_parses(self, filename, logger):

pyfile = os.path.join(self.test_folder, filename)

stem = filename[:-3]

oldfile = os.path.join(self.test_folder, stem + ".old")

newfile = os.path.join(self.test_folder, stem + ".new")

old_error = False

new_error = False

try:

old_ast = old_parser(pyfile, logger)

with open(oldfile, "w") as old:

AstDumper(old).visit(old_ast)

except SyntaxError:

old_error = True

try:

new_ast = new_parser(pyfile, logger)

with open(newfile, "w") as new:

AstDumper(new).visit(new_ast)

except SyntaxError:

new_error = True

if old_error or new_error:

raise Exception("Parser error: old_error={}, new_error={}".format(old_error, new_error))

try:

diff = subprocess.check_output(["git", "diff", "--patience", "--no-index", oldfile, newfile])

except subprocess.CalledProcessError as e:

diff = e.output

if diff:

pytest.fail(diff.decode("utf-8"))

self.check_for_stdout_errors(logger)

self.assertEqual(self.capsys.readouterr().err, "")

os.remove(oldfile)

os.remove(newfile)

def compare_expected(self, filename, logger, new=True ):

if sys.version_info.major < 3:

return

pyfile = os.path.join(self.test_folder, filename)

stem = filename[:-3]

expected = os.path.join(self.test_folder, stem + ".expected")

actual = os.path.join(self.test_folder, stem + ".actual")

parser = new_parser if new else old_parser

with warnings.catch_warnings():

# The test case `b"this is not a unicode escape because we are in a

# bytestring: \N{AMPERSAND}"`` in strings_new.py gives a DeprecationWarning,

# however we are actually testing the parser behavior on such bad code, so

# we can't just "fix" the code. You would think we could use the Python

# warning filter to ignore this specific warning, but that doesn't work --

# furthermore, using `error::DeprecationWarning` makes the *output* of the

# test change :O

#

# This was the best solution I could come up with that _both_ allows pytest

# to error on normal deprecation warnings, but also allows this one case to

# exist.

if filename == "strings_new.py":

warnings.simplefilter("ignore", DeprecationWarning)

ast = parser(pyfile, logger)

with open(actual, "w") as actual_file:

AstDumper(actual_file).visit(ast)

try:

diff = subprocess.check_output(["git", "diff", "--patience", "--no-index", expected, actual])

except subprocess.CalledProcessError as e:

diff = e.output

if diff:

pytest.fail(diff.decode("utf-8"))

self.check_for_stdout_errors(logger)

self.assertEqual(self.capsys.readouterr().err, "")

os.remove(actual)

def check_for_stdout_errors(self, logger):

if logger.had_errors():

logger.reset_error_count()

pytest.fail("Errors/warnings were logged to stdout during testing.")

def setup_tests():

test_folder = os.path.join(os.path.dirname(__file__), "parser")

with StdoutLogger() as logger:

for file in os.listdir(test_folder):

if file.endswith(".py"):

stem = file[:-3]

test_name = "test_" + stem

if stem.endswith("_new"):

test_func = lambda self, file=file: self.compare_expected(file, logger, new=True)

elif stem.endswith("_old"):

test_func = lambda self, file=file: self.compare_expected(file, logger, new=False)

else:

test_func = lambda self, file=file: self.compare_parses(file, logger)

setattr(ParserTest, test_name, test_func)

setup_tests()

del setup_tests