Upgrade to postcss 5.x

[MoOx]

Most plugins are ready but there is still some work to prepare.

[jednano]

Are we just waiting for some plugins to upgrade? If so, can we get a checklist of the ones remaining?

[louh]

Autoprefixer, for one - waiting on that to be v6

[ben-eb]

cssnano 3 will support PostCSS 5. Coming shortly after autoprefixer 6.

[jednano]

It looks like Autoprefixer 6.0.1 and cssnano 3.0 are now released. Is there anything else holding us back now?

[MoOx]

• "autoprefixer": "^6.0.0",
• "cssnano": "^3.0.0",
• "pixrem": "^2.0.0",
• "postcss-calc": "^5.0.0",
• "postcss-color-function": "^2.0.0",
• "postcss-color-gray": "^?",
• "postcss-color-hex-alpha": "^?",
• "postcss-color-hwb": "^?",
• "postcss-color-rebeccapurple": "^?",
• "postcss-color-rgba-fallback": "^2.0.0",
• "postcss-custom-media": "^5.0.0",
• "postcss-custom-properties": "^5.0.0",
• "postcss-custom-selectors": "^3.0.0",
• "postcss-font-variant": "^?",
• "postcss-import": "^7.0.0",
• "postcss-media-minmax": "^2.0.0",
• "postcss-pseudo-class-any-link": "^1.0.0",
• "postcss-pseudoelements": "^?",
• "postcss-reporter": "^1.0.0",
• "postcss-selector-matches": "^2.0.0",
• "postcss-selector-not": "^2.0.0",
• "postcss-url": "^5.0.0",

I can handle all updates except postcss-pseudoelements.

[jednano]

@MoOx you can cross postcss-pseudoelements off the list now. See https://github.com/axa-ch/postcss-pseudoelements/releases/tag/3.0.0

[jednano]

@MoOx see postcss/postcss-color-gray#5

[jednano]

@MoOx see postcss/postcss-color-hex-alpha#5

[jednano]

@MoOx see postcss/postcss-color-hwb#6

[jednano]

@MoOx see postcss/postcss-color-rebeccapurple#6

[jednano]

@MoOx see postcss/postcss-font-variant#7

[onigoetz]

@jedmao nice work !
@MoOx can you merge all these in ? cssnext is the last package in my pipeline on postcss4 and I would love to upgrade it.

[MoOx]

It's not that easy. I think I can't just "merge" yet, because cssnext runners are sync, and plugins like cssnano are now async only.
I will need to release this in a major release, and so, I will probably need to deprecate all runners in favors of postcss ones. But I need to do this the right way, by warning everyone & with a proper changelog on how to upgrade.

That said, I will merge & publish all pr tomorrow so this branch can work if used just as a plugin.
I think I will also release "postcss-cssnext" or something like that, but I didn't get any feedback on #208 and postcss/postcss#477 to take a decision...