Leafo\ScssPhp\Compiler::libStrInsert PHP Method

    protected function libStrInsert($args)
    {
        $string = $this->coerceString($args[0]);
        $stringContent = $this->compileStringContent($string);
        $insert = $this->coerceString($args[1]);
        $insertContent = $this->compileStringContent($insert);
        list(, $index) = $args[2];
        $string[2] = [substr_replace($stringContent, $insertContent, $index - 1, 0)];
        return $string;
    }