Here you can see results of a minificatiors tests. The script downloads a few sites, compress their css files and then launches screenshot testing all sites using gemini. You can view more details under the spoilers.

nodejs.org: No errors!

wordpress.org: No errors!

Simpsons: No errors!

github.com: No errors!

nodejs.org: No errors!

wordpress.org: No errors!

Simpsons: No errors!

github.com: No errors!

nodejs.org: No errors!

wordpress.org: No errors! - diff

bootstrap.min.css
Parse error on line 9:
...d (max-width:400px){@-ms-viewport{width:
-----------------------^
Expecting 'IDENT', 'S', 'BLOCK_MEDIA', '{', '}', ',', ':', 'BLOCK_PAGE', '+', 'SEL_CHILD', 'SEL_SIBLING', 'ID_IDENT', 'HEX_SHORT', 'HEX_LONG', 'CLASS_IDENT', '|', '*', '[', '::', 'NTH_FUNC', 'PSEUDO_CLASS', got 'BLOCK_VENDOR_VIEWPORT'

github.com: No errors!

nodejs.org: No errors!

wordpress.org: No errors! - diff

bootstrap.min.css
Parse error on line 9:
...d (max-width:400px){@-ms-viewport{width:
-----------------------^
Expecting 'IDENT', 'S', 'BLOCK_MEDIA', '{', '}', ',', ':', 'BLOCK_PAGE', '+', 'SEL_CHILD', 'SEL_SIBLING', 'ID_IDENT', 'HEX_SHORT', 'HEX_LONG', 'CLASS_IDENT', '|', '*', '[', '::', 'NTH_FUNC', 'PSEUDO_CLASS', got 'BLOCK_VENDOR_VIEWPORT'

github.com: No errors!

nodejs.org: No errors!

wordpress.org: No errors! - diff

Simpsons: No errors!

github.com: No errors!

nodejs.org: No errors! - diff

wordpress.org: No errors! - diff

Simpsons: No errors! - diff

github.com: No errors!

nodejs.org: No errors!

wordpress.org: No errors!

Simpsons: No errors! - diff

github.com: No errors!

nodejs.org: No errors!

wordpress.org: No errors!

Simpsons: No errors! - diff

github.com: No errors!

nodejs.org: No errors!

wordpress.org: No errors!

Simpsons: No errors!

github.com: No errors!

nodejs.org: No errors!

wordpress.org: No errors!

Simpsons: No errors!

github.com: No errors! - diff

nodejs.org: No errors!

wordpress.org: No errors!

Simpsons: No errors!

github.com: No errors!

css.css
TypeError: Path must be a string. Received undefined
    at assertPath (path.js:7:11)
    at Object.dirname (path.js:1326:5)
    at new CleanCSS (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/node_modules/clean-css/lib/clean.js:55:130)
    at Compress.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:34:18)
    at exports.default (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:11:49)
    at Function.More.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/More.js:430:12)
    at Object.more-css (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:72:30)
    at Object.exports.minify.err [as minify] (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:91:35)
    at promise.then (/home/deeech/Projects/git/css-minificator-tests/lib/processPage.js:48:24)
    at _fulfilled (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:834:54)
    at self.promiseDispatch.done (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:863:30)
    at Promise.promise.promiseDispatch (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:796:13)
    at /home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:604:44
    at runSingle (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:137:13)
    at flush (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:125:13)
    at _combinedTickCallback (internal/process/next_tick.js:67:7)
    at process._tickCallback (internal/process/next_tick.js:98:9)
prism-tomorrow.css
TypeError: Path must be a string. Received undefined
    at assertPath (path.js:7:11)
    at Object.dirname (path.js:1326:5)
    at new CleanCSS (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/node_modules/clean-css/lib/clean.js:55:130)
    at Compress.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:34:18)
    at exports.default (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:11:49)
    at Function.More.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/More.js:430:12)
    at Object.more-css (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:72:30)
    at Object.exports.minify.err [as minify] (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:91:35)
    at promise.then (/home/deeech/Projects/git/css-minificator-tests/lib/processPage.js:48:24)
    at _fulfilled (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:834:54)
    at self.promiseDispatch.done (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:863:30)
    at Promise.promise.promiseDispatch (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:796:13)
    at /home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:604:44
    at runSingle (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:137:13)
    at flush (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:125:13)
    at _combinedTickCallback (internal/process/next_tick.js:67:7)
    at process._tickCallback (internal/process/next_tick.js:98:9)
styles.css
TypeError: Path must be a string. Received undefined
    at assertPath (path.js:7:11)
    at Object.dirname (path.js:1326:5)
    at new CleanCSS (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/node_modules/clean-css/lib/clean.js:55:130)
    at Compress.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:34:18)
    at exports.default (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:11:49)
    at Function.More.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/More.js:430:12)
    at Object.more-css (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:72:30)
    at Object.exports.minify.err [as minify] (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:91:35)
    at promise.then (/home/deeech/Projects/git/css-minificator-tests/lib/processPage.js:48:24)
    at _fulfilled (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:834:54)
    at self.promiseDispatch.done (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:863:30)
    at Promise.promise.promiseDispatch (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:796:13)
    at /home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:604:44
    at runSingle (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:137:13)
    at flush (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:125:13)
    at _combinedTickCallback (internal/process/next_tick.js:67:7)
    at process._tickCallback (internal/process/next_tick.js:98:9)
css.css
TypeError: Path must be a string. Received undefined
    at assertPath (path.js:7:11)
    at Object.dirname (path.js:1326:5)
    at new CleanCSS (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/node_modules/clean-css/lib/clean.js:55:130)
    at Compress.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:34:18)
    at exports.default (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:11:49)
    at Function.More.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/More.js:430:12)
    at Object.more-css (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:72:30)
    at Object.exports.minify.err [as minify] (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:91:35)
    at promise.then (/home/deeech/Projects/git/css-minificator-tests/lib/processPage.js:48:24)
    at _fulfilled (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:834:54)
    at self.promiseDispatch.done (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:863:30)
    at Promise.promise.promiseDispatch (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:796:13)
    at /home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:604:44
    at runSingle (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:137:13)
    at flush (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:125:13)
    at _combinedTickCallback (internal/process/next_tick.js:67:7)
    at process._tickCallback (internal/process/next_tick.js:98:9)
dashicons.css
TypeError: Path must be a string. Received undefined
    at assertPath (path.js:7:11)
    at Object.dirname (path.js:1326:5)
    at new CleanCSS (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/node_modules/clean-css/lib/clean.js:55:130)
    at Compress.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:34:18)
    at exports.default (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:11:49)
    at Function.More.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/More.js:430:12)
    at Object.more-css (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:72:30)
    at Object.exports.minify.err [as minify] (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:91:35)
    at promise.then (/home/deeech/Projects/git/css-minificator-tests/lib/processPage.js:48:24)
    at _fulfilled (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:834:54)
    at self.promiseDispatch.done (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:863:30)
    at Promise.promise.promiseDispatch (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:796:13)
    at /home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:604:44
    at runSingle (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:137:13)
    at flush (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:125:13)
    at _combinedTickCallback (internal/process/next_tick.js:67:7)
    at process._tickCallback (internal/process/next_tick.js:98:9)
ie.css
TypeError: Path must be a string. Received undefined
    at assertPath (path.js:7:11)
    at Object.dirname (path.js:1326:5)
    at new CleanCSS (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/node_modules/clean-css/lib/clean.js:55:130)
    at Compress.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:34:18)
    at exports.default (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:11:49)
    at Function.More.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/More.js:430:12)
    at Object.more-css (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:72:30)
    at Object.exports.minify.err [as minify] (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:91:35)
    at promise.then (/home/deeech/Projects/git/css-minificator-tests/lib/processPage.js:48:24)
    at _fulfilled (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:834:54)
    at self.promiseDispatch.done (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:863:30)
    at Promise.promise.promiseDispatch (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:796:13)
    at /home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:604:44
    at runSingle (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:137:13)
    at flush (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:125:13)
    at _combinedTickCallback (internal/process/next_tick.js:67:7)
    at process._tickCallback (internal/process/next_tick.js:98:9)
iphone.css
TypeError: Path must be a string. Received undefined
    at assertPath (path.js:7:11)
    at Object.dirname (path.js:1326:5)
    at new CleanCSS (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/node_modules/clean-css/lib/clean.js:55:130)
    at Compress.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:34:18)
    at exports.default (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:11:49)
    at Function.More.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/More.js:430:12)
    at Object.more-css (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:72:30)
    at Object.exports.minify.err [as minify] (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:91:35)
    at promise.then (/home/deeech/Projects/git/css-minificator-tests/lib/processPage.js:48:24)
    at _fulfilled (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:834:54)
    at self.promiseDispatch.done (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:863:30)
    at Promise.promise.promiseDispatch (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:796:13)
    at /home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:604:44
    at runSingle (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:137:13)
    at flush (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:125:13)
    at _combinedTickCallback (internal/process/next_tick.js:67:7)
    at process._tickCallback (internal/process/next_tick.js:98:9)
wp4.css
TypeError: Path must be a string. Received undefined
    at assertPath (path.js:7:11)
    at Object.dirname (path.js:1326:5)
    at new CleanCSS (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/node_modules/clean-css/lib/clean.js:55:130)
    at Compress.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:34:18)
    at exports.default (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:11:49)
    at Function.More.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/More.js:430:12)
    at Object.more-css (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:72:30)
    at Object.exports.minify.err [as minify] (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:91:35)
    at promise.then (/home/deeech/Projects/git/css-minificator-tests/lib/processPage.js:48:24)
    at _fulfilled (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:834:54)
    at self.promiseDispatch.done (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:863:30)
    at Promise.promise.promiseDispatch (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:796:13)
    at /home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:604:44
    at runSingle (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:137:13)
    at flush (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:125:13)
    at _combinedTickCallback (internal/process/next_tick.js:67:7)
    at process._tickCallback (internal/process/next_tick.js:98:9)
bootstrap.min.css
TypeError: Path must be a string. Received undefined
    at assertPath (path.js:7:11)
    at Object.dirname (path.js:1326:5)
    at new CleanCSS (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/node_modules/clean-css/lib/clean.js:55:130)
    at Compress.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:34:18)
    at exports.default (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:11:49)
    at Function.More.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/More.js:430:12)
    at Object.more-css (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:72:30)
    at Object.exports.minify.err [as minify] (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:91:35)
    at promise.then (/home/deeech/Projects/git/css-minificator-tests/lib/processPage.js:48:24)
    at _fulfilled (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:834:54)
    at self.promiseDispatch.done (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:863:30)
    at Promise.promise.promiseDispatch (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:796:13)
    at /home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:604:44
    at runSingle (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:137:13)
    at flush (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:125:13)
    at _combinedTickCallback (internal/process/next_tick.js:67:7)
    at process._tickCallback (internal/process/next_tick.js:98:9)
characters.min.css
TypeError: Path must be a string. Received undefined
    at assertPath (path.js:7:11)
    at Object.dirname (path.js:1326:5)
    at new CleanCSS (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/node_modules/clean-css/lib/clean.js:55:130)
    at Compress.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:34:18)
    at exports.default (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:11:49)
    at Function.More.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/More.js:430:12)
    at Object.more-css (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:72:30)
    at Object.exports.minify.err [as minify] (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:91:35)
    at promise.then (/home/deeech/Projects/git/css-minificator-tests/lib/processPage.js:48:24)
    at _fulfilled (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:834:54)
    at self.promiseDispatch.done (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:863:30)
    at Promise.promise.promiseDispatch (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:796:13)
    at /home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:604:44
    at runSingle (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:137:13)
    at flush (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:125:13)
    at _combinedTickCallback (internal/process/next_tick.js:67:7)
    at process._tickCallback (internal/process/next_tick.js:98:9)
styles.css
TypeError: Path must be a string. Received undefined
    at assertPath (path.js:7:11)
    at Object.dirname (path.js:1326:5)
    at new CleanCSS (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/node_modules/clean-css/lib/clean.js:55:130)
    at Compress.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:34:18)
    at exports.default (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:11:49)
    at Function.More.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/More.js:430:12)
    at Object.more-css (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:72:30)
    at Object.exports.minify.err [as minify] (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:91:35)
    at promise.then (/home/deeech/Projects/git/css-minificator-tests/lib/processPage.js:48:24)
    at _fulfilled (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:834:54)
    at self.promiseDispatch.done (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:863:30)
    at Promise.promise.promiseDispatch (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:796:13)
    at /home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:604:44
    at runSingle (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:137:13)
    at flush (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:125:13)
    at _combinedTickCallback (internal/process/next_tick.js:67:7)
    at process._tickCallback (internal/process/next_tick.js:98:9)
frameworks-c90d888b6f5151dadd198c29754c69062ad2d2b96ccd6484e1439cff77089623.css
TypeError: Path must be a string. Received undefined
    at assertPath (path.js:7:11)
    at Object.dirname (path.js:1326:5)
    at new CleanCSS (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/node_modules/clean-css/lib/clean.js:55:130)
    at Compress.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:34:18)
    at exports.default (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:11:49)
    at Function.More.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/More.js:430:12)
    at Object.more-css (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:72:30)
    at Object.exports.minify.err [as minify] (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:91:35)
    at promise.then (/home/deeech/Projects/git/css-minificator-tests/lib/processPage.js:48:24)
    at _fulfilled (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:834:54)
    at self.promiseDispatch.done (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:863:30)
    at Promise.promise.promiseDispatch (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:796:13)
    at /home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:604:44
    at runSingle (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:137:13)
    at flush (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:125:13)
    at _combinedTickCallback (internal/process/next_tick.js:67:7)
    at process._tickCallback (internal/process/next_tick.js:98:9)
github-7b16dd23c5b6a726689820e31b4f28ae30b7665e509b93ef4ccf1f09c84fef61.css
TypeError: Path must be a string. Received undefined
    at assertPath (path.js:7:11)
    at Object.dirname (path.js:1326:5)
    at new CleanCSS (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/node_modules/clean-css/lib/clean.js:55:130)
    at Compress.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:34:18)
    at exports.default (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:11:49)
    at Function.More.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/More.js:430:12)
    at Object.more-css (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:72:30)
    at Object.exports.minify.err [as minify] (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:91:35)
    at promise.then (/home/deeech/Projects/git/css-minificator-tests/lib/processPage.js:48:24)
    at _fulfilled (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:834:54)
    at self.promiseDispatch.done (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:863:30)
    at Promise.promise.promiseDispatch (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:796:13)
    at /home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:604:44
    at runSingle (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:137:13)
    at flush (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:125:13)
    at _combinedTickCallback (internal/process/next_tick.js:67:7)
    at process._tickCallback (internal/process/next_tick.js:98:9)
site-7cc71df50ca0ee0accd9016b40404b47db9123deb18de17f0c88ce650ce696d1.css
TypeError: Path must be a string. Received undefined
    at assertPath (path.js:7:11)
    at Object.dirname (path.js:1326:5)
    at new CleanCSS (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/node_modules/clean-css/lib/clean.js:55:130)
    at Compress.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:34:18)
    at exports.default (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/compress.js:11:49)
    at Function.More.compress (/home/deeech/Projects/git/css-minificator-tests/node_modules/more-css/build/More.js:430:12)
    at Object.more-css (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:72:30)
    at Object.exports.minify.err [as minify] (/home/deeech/Projects/git/css-minificator-tests/lib/minifiers.js:91:35)
    at promise.then (/home/deeech/Projects/git/css-minificator-tests/lib/processPage.js:48:24)
    at _fulfilled (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:834:54)
    at self.promiseDispatch.done (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:863:30)
    at Promise.promise.promiseDispatch (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:796:13)
    at /home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:604:44
    at runSingle (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:137:13)
    at flush (/home/deeech/Projects/git/css-minificator-tests/node_modules/q/q.js:125:13)
    at _combinedTickCallback (internal/process/next_tick.js:67:7)
    at process._tickCallback (internal/process/next_tick.js:98:9)
css.css
RangeError: Maximum call stack size exceeded
    at _buffer (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/parser.js:65:19)
    at q (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/parser.js:81:12)
    at Object.handle [as token] (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/parser.js:215:9)
    at next (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:113:12)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:74:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
css.css
RangeError: Maximum call stack size exceeded
    at write (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/parser.js:49:17)
    at _buffer (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/parser.js:66:5)
    at q (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/parser.js:81:12)
    at Object.handle [as token] (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/parser.js:215:9)
    at next (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:113:12)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:74:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
dashicons.css
RangeError: Maximum call stack size exceeded
    at write (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/parser.js:49:17)
    at _buffer (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/parser.js:66:5)
    at q (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/parser.js:81:12)
    at Object.handle [as token] (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/parser.js:215:9)
    at next (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:113:12)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:74:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
wp4.css
RangeError: Maximum call stack size exceeded
    at String.toLowerCase (native)
    at Object.handle [as token] (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/parser.js:245:21)
    at next (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:113:12)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:74:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)
    at tokenize (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:138:7)
    at num (/home/deeech/Projects/git/css-minificator-tests/node_modules/ncss/lib/lexer.js:77:7)

Simpsons: No errors! - diff

github.com: No errors!

nodejs.org: No errors!

wordpress.org: No errors!

Simpsons: No errors!

github.com: No errors!

nodejs.org: No errors!

wordpress.org: No errors!

Simpsons: No errors!

github.com: No errors!