PostCSS Clear Flex

PostCSS plugin clear old webkit flex prefixes to prevent wrong order in the autoprefixer output.

If you have to use prefixed sources like Uikit 2 and need to support browsers with old flexbox specification like Safari 6, Android 4.3, Blackberry 7, Autoprefixer will produce wrong prefixes order

/* source */
.foo {
    display: -webkit-flex;
    display: flex;
}
 
/* output from Autoprefixer with config "Safari 6, Safari 8" */
.foo {
  display: -webkit-flex;
  display: -webkit-box; 
  /* ^^^ old prefix get higher priority than new prefix, Safari 8 will be forced to use old flexbox specification and layout will break */
  display: flex;
}

To prevent it this plugin clear flexbox prefixes so Autoprefixer will apply prefixes from scratch with correct order

/* source */
.foo {
    display: -webkit-flex;
    display: flex;
}
 
/* postcss-clear-flex */
.foo {
  display: flex;
}
 
/* Autoprefixer */
.foo {
    display: -ms-flexbox;
    display: -webkit-box;
    display: -webkit-flex;
    display: flex;
}

Usage

postcss-clear-flex should be used before Autoprefixer

postcss([ require('postcss-clear-flex') ])

See PostCSS docs for examples for your environment.