[postcss-preset-env] what happen when a feature is rejected ?

[fchastanet]

Hello,

Let's say I'm using a stage 2 feature and this feature is rejected. Would this feature be kept in cssdb ?
if this is not the case, my next css build could miss the polyfill and my frontend being impacted.

[romainmenke]

Hi!

Any drop in stage or in the number of implementations is indeed very tricky.
Users of postcss-preset-env expect a given source to have a stable output for a given config.

Normally we would detect these and make it a breaking change in both cssdb and postcss-preset-env.

This happened with :
https://github.com/csstools/postcss-color-mod-function

It was only removed when we released postcss-preset-env v7 with PostCSS 8 support.

To help users migrate their source code I created this :

https://github.com/romainmenke/postcss-preset-env-migrations

It has two things and you pick one :

• a tiny plugin pack that includes the removed plugins. (intended as a stop-gap measure)
• a VSCode extension that makes it easy to convert source code to a native alternative. (real solution)

At the moment I intend to keep track of breaking changes in postcss-preset-env and add more migrations there.