The toml module dependency is used to optionally read the line-length and skip-string-normalization options from pyproject.toml. However, reading and applying those optins is contingent on the toml module being installed into the elpy RPV venv, or they are silently skipped.
This can lead to quite confusing behaviour, where two computers which, to elpy-config, appear to have equivalent configs, will have differing behaviour in the wrapping they create when they run black.
We should either make toml a requirement when installing black, or document that the behaviour of elpy-black-fix-code depends on if toml is installed in the venv.
Steps to reproduce
Clean out the RPV venv (rm -rf ~/.emacs.d/elpy/rpc-venv
Install black into the fresh venv
Create a pyproject.toml with:
[tool.black]
line-length = 50
Run elpy-black-fix-code on some code, see it use the default 88-character limit
Install toml into the venv
Re-run elpy-black-fix-code, and watch the line-lengths change to pick up the 50-character limit
Summary
The
tomlmodule dependency is used to optionally read theline-lengthandskip-string-normalizationoptions frompyproject.toml. However, reading and applying those optins is contingent on thetomlmodule being installed into theelpyRPV venv, or they are silently skipped.This can lead to quite confusing behaviour, where two computers which, to
elpy-config, appear to have equivalent configs, will have differing behaviour in the wrapping they create when they runblack.We should either make
tomla requirement when installingblack, or document that the behaviour ofelpy-black-fix-codedepends on iftomlis installed in the venv.Steps to reproduce
rm -rf ~/.emacs.d/elpy/rpc-venvblackinto the fresh venvpyproject.tomlwith:elpy-black-fix-codeon some code, see it use the default 88-character limittomlinto the venvelpy-black-fix-code, and watch the line-lengths change to pick up the 50-character limit