Controlling Flake8-AAA

In code

Flake8-AAA can be controlled using some special comments in your test code.

Explicitly marking blocks

One can set the act block explicitly using the # act comment. This is necessary when there is no assignment possible.

Disabling Flake8-AAA selectively

When invoked via Flake8, Flake8 will filter any errors raised when lines are marked with the # noqa syntax. You can turn off all errors from Flake8-AAA by marking a line with # noqa: AAA and other Flake8 errors will still be returned.

If you just want to ignore a particular error, then you can use the more specific code and indicate the exact error to be ignored. For example, to ignore the check for a space before the Act block, we can mark the Act block with # noqa: AAA03:

def test():
    x = 1
    result = x + 1  # noqa: AAA03

    assert result == 2

Command line

Flake8-AAA has a simple command line interface to assist with development and debugging. Its goal is to show the state of analysed test functions, which lines are considered to be parts of which blocks and any errors that have been found.

Invocation, output and return value

With Flake8-AAA installed, it can be called as a Python module:

$ python -m flake8_aaa [test_file]

Where [test_file] is the path to a file to be checked.

The return value of the execution is the number of errors found in the file, for example:

$ python -m flake8_aaa
 1 DEF|def test():
 2 ARR|    x = 1
 3 ARR|    y = 1
       ^ AAA03 expected 1 blank line before Act block, found none
 4 ACT|    result = x + y
 5 BL |
 6 ASS|    assert result == 2
    1 | ERROR
        FAILED with 1 ERROR
$ echo "$?"

And once the error above is fixed, the return value returns to zero:

$ python -m flake8_aaa
 1 DEF|def test():
 2 ARR|    x = 1
 3 ARR|    y = 1
 4 BL |
 5 ACT|    result = x + y
 6 BL |
 7 ASS|    assert result == 2
    0 | ERRORS
$ echo "$?"

Only one file can be passed to the command line at a time. So to test all files in a test suite, find should be used:

$ find tests -name '*.py' | xargs -n 1 python -m flake8_aaa

noqa and command line

The # noqa comment marker works slightly differently when Flake8-AAA is called on the command line rather than invoked through flake8. When called on the command line, to skip linting a test function, mark the function definition with # noqa on the same line as the def.

For example:

def test_to_be_ignored(  # noqa

Line markers

Each test found in the passed file is displayed. Each line is annotated with its line number in the file and a marker to show how Flake8-AAA classified that line. Line markers are as follows:

Line is part of the Act Block.
Line is part of an Arrange Block.
Line is part of the Assert Block.
Line is considered a blank line for layout purposes.
Line is a # comment.
Test function definition.
Unprocessed line. Flake8-AAA has not categorised this line.