X-Git-Url: https://git.madduck.net/etc/vim.git/blobdiff_plain/1382eabb3f27d7c9cd5328fb7fddd1ded98121fb..c3df2c1a69c687d34f41478235c869d0526a46bd:/CONTRIBUTING.md

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 91e5320..a4250f7 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -19,12 +19,12 @@ unlikely to get accepted. You can still try but prepare to be disappointed.
 
 ## Technicalities
 
-Development on the latest version of Python is preferred. As of this writing it's 3.8.
+Development on the latest version of Python is preferred. As of this writing it's 3.9.
 You can use any operating system. I am using macOS myself and CentOS at work.
 
 Install all development dependencies using:
 
-```
+```console
 $ pipenv install --dev
 $ pipenv shell
 $ pre-commit install
@@ -34,12 +34,26 @@ If you haven't used `pipenv` before but are comfortable with virtualenvs, just r
 `pip install pipenv` in the virtualenv you're already using and invoke the command above
 from the cloned _Black_ repo. It will do the correct thing.
 
-Before submitting pull requests, run tests with:
+Before submitting pull requests, run lints and tests with:
 
-```
+```console
+$ pre-commit run -a
 $ python -m unittest
+$ black-primer [-k -w /tmp/black_test_repos]
 ```
 
+## black-primer
+
+`black-primer` is used by CI to pull down well-known _Black_ formatted projects and see
+if we get source code changes. It will error on formatting changes or errors. Please run
+before pushing your PR to see if you get the actions you would expect from _Black_ with
+your PR. You may need to change
+[primer.json](https://github.com/psf/black/blob/master/src/black_primer/primer.json)
+configuration for it to pass.
+
+For more `black-primer` information visit the
+[documentation](https://github.com/psf/black/blob/master/docs/black_primer.md#black-primer).
+
 ## Hygiene
 
 If you're fixing a bug, add a test. Run it first to confirm it fails, then fix the bug,