pytest.el custom runner

I started using Spacemacs some weeks ago, and there is not too much more to add than what I wrote in the README of my Emacs' configuration

I used to have a very customized Emacs configuration with lot of packages, hotkeys, custom variables and a lot of things. Then, one day, I met Spacemacs. Basically, it is exactly what I had but better and maintained by other people.

—me

We have a very custom way to run tests:

• use a specific virtualenv
• we run the test inside docker
• we use a docker-compose wrapper made with invoke
• we use tox to run pytest
• filepath of test file in host does not exist in the container
• etc

Basically, we need a very specific command to run the test and, of course that pytest.el won't know what to do here, and it will fail even trying to guess hard. So, I needed a way to customize what is the command that pytest.el is going to execute. Fortunately, the author already thought on some variables that helped me to make me happy -but there is one function that can't be replaced using a customizable variable. I had to override it.

1. Define the variables I need in .dir-locals.el, so it only affects the project I want

   ((python-mode
     (pytest-cmd-flags . "-x")
     (pytest-global-name . "~/.pyenv/versions/readthedocs.org/bin/inv docker.test -a")
     (pytest-cmd-format-string . "cd '%s' && %s '-e py36 -- %s %s'")
     (pytest-remove-path . "/home/humitos/rtfd/code/readthedocs.org/readthedocs/")))  ;; Extra variable added by myself
   

2. Override pytest.el pytest-cmd-format function

   ;; .emacs.d/private/local/docker-tox-pytest.el
   (defcustom pytest-remove-path ""
     "Path to remove from pytest test-names variable")
   
   (with-eval-after-load 'pytest
     (defun pytest-cmd-format (format-string working-directory test-runner command-flags test-names)
       "Override default function to remove local path."
       (format format-string working-directory test-runner command-flags (replace-regexp-in-string pytest-remove-path "" test-names)))
     )
   

3. Load my docker-tox-pytest.el file from Spacemacs

   (load "~/.emacs.d/private/local/docker-tox-pytest.el")
   

That's all!

Now a simple SPC m t t somewhere in the function that I want to test will call the command I need and will execute only that test.