:host-context selectors are being optimized incorrectly in level 2

[alan-agius4]

Precheck

• Do a quick search and make sure a bug has not yet been reported;
• do a quick check if the bug still exists in the latest patch version;
• finally, be nice and have fun!

Environment

• clean-css version - 4.2.1:
• node.js version - 10.12:
• operating system: Win32

Configuration options

var CleanCSS = require('clean-css');
new CleanCSS({
    compatibility: 'ie9',
    level: 2,
    format: {
        aroundSelectorRelation: false,
    },
    inline: false,
    returnPromise: true,
    sourceMap: this._options.sourceMap,
});

Input CSS

:host-context(selector selector){
	color: red;
}

Actual output CSS

:host-context(selectorselector){color:red}

Expected output CSS

:host-context(selector selector){color:red}

[SebastianPodgajny]

Problem is in level 1 tidySelectors option

Here is code that skips this space
isWhitespace = true
roundBracketLevel = 1
isQuoted = false
https://github.com/jakubpawlowicz/clean-css/blob/dc728a8167b7b6f62906115c560be2f5b530f9f6/lib/optimizer/level-1/tidy-rules.js#L114-L115