flake8/tests/integration/test_main.py

"""Integration tests for the main entrypoint of flake8."""
import json
import os

import mock
import pytest

from flake8 import utils
from flake8.main import cli


def _call_main(argv, retv=0):
    with pytest.raises(SystemExit) as excinfo:
        cli.main(argv)
    assert excinfo.value.code == retv


def test_diff_option(tmpdir, capsys):
    """Ensure that `flake8 --diff` works."""
    t_py_contents = '''\
import os
import sys  # unused but not part of diff

print('(to avoid trailing whitespace in test)')
print('(to avoid trailing whitespace in test)')
print(os.path.join('foo', 'bar'))

y  # part of the diff and an error
'''

    diff = '''\
diff --git a/t.py b/t.py
index d64ac39..7d943de 100644
--- a/t.py
+++ b/t.py
@@ -4,3 +4,5 @@ import sys  # unused but not part of diff
 print('(to avoid trailing whitespace in test)')
 print('(to avoid trailing whitespace in test)')
 print(os.path.join('foo', 'bar'))
+
+y  # part of the diff and an error
'''

    with mock.patch.object(utils, 'stdin_get_value', return_value=diff):
        with tmpdir.as_cwd():
            tmpdir.join('t.py').write(t_py_contents)
            _call_main(['--diff'], retv=1)

    out, err = capsys.readouterr()
    assert out == "t.py:8:1: F821 undefined name 'y'\n"
    assert err == ''


def test_e101_indent_char_does_not_reset(tmpdir, capsys):
    """Ensure that E101 with an existing indent_char does not reset it."""
    t_py_contents = """\
if True:
    print('space indented')

s = '''\
\ttab indented
'''  # noqa: E101

if True:
    print('space indented')
"""

    with tmpdir.as_cwd():
        tmpdir.join('t.py').write(t_py_contents)
        _call_main(['t.py'])


def test_statistics_option(tmpdir, capsys):
    """Ensure that `flake8 --statistics` works."""
    with tmpdir.as_cwd():
        tmpdir.join('t.py').write('import os\nimport sys\n')
        _call_main(['--statistics', 't.py'], retv=1)

    out, err = capsys.readouterr()
    assert out == '''\
t.py:1:1: F401 'os' imported but unused
t.py:2:1: F401 'sys' imported but unused
2     F401 'os' imported but unused
'''
    assert err == ''


def test_extend_exclude(tmpdir, capsys):
    """Ensure that `flake8 --extend-exclude` works."""
    for d in ['project', 'vendor', 'legacy', '.git', '.tox', '.hg']:
        tmpdir.mkdir(d).join('t.py').write('import os\nimport sys\n')

    with tmpdir.as_cwd():
        _call_main(['--extend-exclude=vendor,legacy'], retv=1)

    out, err = capsys.readouterr()
    expected_out = '''\
./project/t.py:1:1: F401 'os' imported but unused
./project/t.py:2:1: F401 'sys' imported but unused
'''
    assert out == expected_out.replace('/', os.sep)
    assert err == ''


def test_malformed_per_file_ignores_error(tmpdir, capsys):
    """Test the error message for malformed `per-file-ignores`."""
    setup_cfg = '''\
[flake8]
per-file-ignores =
    incorrect/*
    values/*
'''

    with tmpdir.as_cwd():
        tmpdir.join('setup.cfg').write(setup_cfg)
        _call_main(['.'], retv=1)

    out, err = capsys.readouterr()
    assert out == '''\
There was a critical error during execution of Flake8:
Expected `per-file-ignores` to be a mapping from file exclude patterns to ignore codes.

Configured `per-file-ignores` setting:

    incorrect/*
    values/*
'''  # noqa: E501


def test_tokenization_error_but_not_syntax_error(tmpdir, capsys):
    """Test that flake8 does not crash on tokenization errors."""
    with tmpdir.as_cwd():
        # this is a crash in the tokenizer, but not in the ast
        tmpdir.join('t.py').write("b'foo' \\\n")
        _call_main(['t.py'], retv=1)

    out, err = capsys.readouterr()
    assert out == 't.py:1:1: E902 TokenError: EOF in multi-line statement\n'
    assert err == ''


def test_bug_report_successful(capsys):
    """Test that --bug-report does not crash."""
    _call_main(['--bug-report'])
    out, err = capsys.readouterr()
    assert json.loads(out)
    assert err == ''


def test_obtaining_args_from_sys_argv_when_not_explicity_provided(capsys):
    """Test that arguments are obtained from 'sys.argv'."""
    with mock.patch('sys.argv', ['flake8', '--help']):
        _call_main(None)

    out, err = capsys.readouterr()
    assert out.startswith('usage: flake8 [options] file file ...\n')
    assert err == ''