flake8/tests/unit/test_base_formatter.py
Ian Cordasco e93aad6043
Open our output file in append mode always
This avoid overwriting portions of our log output when using Flake8
in verbose mode.

Closes #193
2016-07-29 18:14:14 -05:00

151 lines
4.4 KiB
Python

"""Tests for the BaseFormatter object."""
import optparse
import mock
import pytest
from flake8 import style_guide
from flake8.formatting import base
def options(**kwargs):
"""Create an optparse.Values instance."""
kwargs.setdefault('output_file', None)
return optparse.Values(kwargs)
@pytest.mark.parametrize('filename', [None, 'out.txt'])
def test_start(filename):
"""Verify we open a new file in the start method."""
mock_open = mock.mock_open()
formatter = base.BaseFormatter(options(output_file=filename))
with mock.patch('flake8.formatting.base.open', mock_open):
formatter.start()
if filename is None:
assert mock_open.called is False
else:
mock_open.assert_called_once_with(filename, 'a')
def test_stop():
"""Verify we close open file objects."""
filemock = mock.Mock()
formatter = base.BaseFormatter(options())
formatter.output_fd = filemock
formatter.stop()
filemock.close.assert_called_once_with()
assert formatter.output_fd is None
def test_format_needs_to_be_implemented():
"""Ensure BaseFormatter#format raises a NotImplementedError."""
formatter = base.BaseFormatter(options())
with pytest.raises(NotImplementedError):
formatter.format('foo')
def test_show_source_returns_nothing_when_not_showing_source():
"""Ensure we return nothing when users want nothing."""
formatter = base.BaseFormatter(options(show_source=False))
assert formatter.show_source(
style_guide.Error('A000', 'file.py', 1, 1, 'error text', 'line')
) is ''
def test_show_source_returns_nothing_when_there_is_source():
"""Ensure we return nothing when there is no line."""
formatter = base.BaseFormatter(options(show_source=True))
assert formatter.show_source(
style_guide.Error('A000', 'file.py', 1, 1, 'error text', None)
) is ''
@pytest.mark.parametrize('line, column', [
('x=1\n', 2),
(' x=(1\n +2)\n', 5),
# TODO(sigmavirus24): Add more examples
])
def test_show_source_updates_physical_line_appropriately(line, column):
"""Ensure the error column is appropriately indicated."""
formatter = base.BaseFormatter(options(show_source=True))
error = style_guide.Error('A000', 'file.py', 1, column, 'error', line)
output = formatter.show_source(error)
_, pointer = output.rsplit('\n', 1)
assert pointer.count(' ') == (column - 1)
def test_write_uses_an_output_file():
"""Verify that we use the output file when it's present."""
line = 'Something to write'
source = 'source'
filemock = mock.Mock()
formatter = base.BaseFormatter(options())
formatter.output_fd = filemock
formatter.write(line, source)
assert filemock.write.called is True
assert filemock.write.call_count == 2
assert filemock.write.mock_calls == [
mock.call(line + formatter.newline),
mock.call(source + formatter.newline),
]
@mock.patch('flake8.formatting.base.print')
def test_write_uses_print(print_function):
"""Verify that we use the print function without an output file."""
line = 'Something to write'
source = 'source'
formatter = base.BaseFormatter(options())
formatter.write(line, source)
assert print_function.called is True
assert print_function.call_count == 2
assert print_function.mock_calls == [
mock.call(line),
mock.call(source),
]
class AfterInitFormatter(base.BaseFormatter):
"""Subclass for testing after_init."""
def after_init(self):
"""Define method to verify operation."""
self.post_initialized = True
def test_after_init_is_always_called():
"""Verify after_init is called."""
formatter = AfterInitFormatter(options())
assert getattr(formatter, 'post_initialized') is True
class FormatFormatter(base.BaseFormatter):
"""Subclass for testing format."""
def format(self, error):
"""Define method to verify operation."""
return repr(error)
def test_handle_formats_the_error():
"""Verify that a formatter will call format from handle."""
formatter = FormatFormatter(options(show_source=False))
filemock = formatter.output_fd = mock.Mock()
error = style_guide.Error(
code='A001',
filename='example.py',
line_number=1,
column_number=1,
text='Fake error',
physical_line='a = 1',
)
formatter.handle(error)
filemock.write.assert_called_once_with(repr(error) + '\n')