.mx-auto missing in latest version?

[ryanscherler]

I updated tailwind to 0.3.0 and it seems to be missing the .mx-auto (container centering) class? Has anyone else experienced this oddity?

[adamwathan]

Hey @ryanscherler, it sounds like you are updating from 0.1.x straight to 0.3.0.

One of the changes in 0.2 was moving auto to the default margin configuration instead of being a hard-coded value:

https://github.com/tailwindcss/tailwindcss/releases#auto-is-no-longer-a-hard-coded-margin-value

You just need to update your config file to include auto like the latest default config file does:

https://github.com/tailwindcss/tailwindcss/blob/master/defaultConfig.stub.js#L634-L659

EDIT: To clarify, it used to be a hard-coded value because we only generated mx-auto, ml-auto, and mr-auto. Another contributor presented a case for adding the vertical versions of those, at which point it didn't make sense to hard-code them into the generator anymore and instead made more sense to just make auto the same as any other value, like we do for width: auto with w-auto, or z-index: auto with z-auto.

[ryanscherler]

This makes total sense, thanks @adamwathan