lbolla / emacs-flycheck-mypy Goto Github PK

I've installed this, and mypy. On a test source file from the command line, when I run mypy, I get a proper error about a mismatched type hint.

I have Flycheck running on the same source file in emacs, but I'm not sure how to activate the mypy features of your script, which is installed. I see FlyC in the mode line, but flycheck-next-error and other similar commands report no errors. What do I need to do to actually run the mypy checker with flycheck?

Also -- there is a comment in your source about desiring deactivation of flake8 -- I find the flake8 syntax checking fantastic, and since this is a different task than mypy, it's not clear to me why I cannot use both?

Thanks, looking forward to getting this working!

I activated some of mypy's additional flags and I'm getting the following output:

tools.py:14: note: unused 'type: ignore' comment

Which triggers the following message in emacs:

Suspicious state from syntax checker python-mypy: Flycheck checker python-mypy returned non-zero exit code 1, but its output contained no errors: tools.py:16: note: unused 'type: ignore' comment

Would you like to contribute this syntax checker to Flycheck itself?

I have the following directory structure (standard for a python package I think):

module/
    __init__.py
    ...
tests/
    test_xxx.py
setup.cfg
setup.py

I have installed the module doing pip install -e ..

Problem

When running mypy from the command line, there are no issues with test_xxx.py. When running flycheck-mypy from emacs, I got tons of warnings similar to:

test_settings.py:7: error: Cannot find implementation or library stub for module named 'module.settings'

The problem occurs because flycheck run mypy from the tests folder and not the root one. Even if I specify a mypy config file, the error persists.

Potential fix

There is :working-directory option for flycheck checkers that could be used. Mine look like this (only works for setup.cfg currently):

(defun flycheck-mypy--find-project-root (_checker)
  "Compute an appropriate working-directory for flycheck-ruby.
This is either a parent directory containing a Gemfile, or nil."
  (and
   buffer-file-name
   (locate-dominating-file buffer-file-name "setup.cfg")))

(flycheck-define-checker python-mypy
  "Mypy syntax checker. Requires mypy>=0.3.1.

Customize `flycheck-python-mypy-args` to add specific args to default
executable.

E.g. when processing Python2 files, add \"--py2\".

See URL `http://mypy-lang.org/'."

  :command ("mypy"
            (config-file "--config-file" flycheck-mypy.ini)
            (eval flycheck-python-mypy-args)
            source-original)
  :working-directory flycheck-mypy--find-project-root
  :error-patterns
  ((error line-start (file-name) ":" line ": error:" (message) line-end)
   (warning line-start (file-name) ":" line ": note:" (message) line-end)
   (info line-start (file-name) ":" line ": note:" (message) line-end))
  :modes python-mode)

(add-to-list 'flycheck-checkers 'python-mypy t)

It should be possible to adapt this to either have a variable to define the directory, or use the directory of flycheck-mypy.ini.