MacOs Slack Dark Mode App/Script (You can Use appify[https://gist.github.com/mathiasbynens/674099] to turn this into an app)

gistfile1.txt

#!/usr/bin/env bash

# If the file has already been modified don't try and modify it again
if grep -Fq "slack-night-mode" /Applications/Slack.app/Contents/Resources/app.asar.unpacked/src/static/ssb-interop.js; then
   /usr/bin/osascript <<EOA
       tell app "System Events"
         display notification "Dark Mode enabled previously.\rYou have made your choice to forsake the Light Mode." with title "Slack Dark Mode"
       end tell
EOA
   exit 0;
fi

# Append the dark mode patch to the file but request the users password so they have access ot modify the file
/usr/bin/osascript -e 'do shell script "
cat <<EOB >> /Applications/Slack.app/Contents/Resources/app.asar.unpacked/src/static/ssb-interop.js

document.addEventListener(\"DOMContentLoaded\", function() {                                                                                                                                                                 [ruby-2.5.1p57]
      let tt__customCss = \".menu ul li a:not(.inline_menu_link) {color: #fff }\"
      $.ajax({
           url: \"https://cdn.rawgit.com/laCour/slack-night-mode/master/css/raw/black.css\",
          success: function(css) {
              $(\"<style></style>\").appendTo(\"head\").html(css + tt__customCss);
          }
     });
});
EOB

# Success and error message handleing
if [[ $? -eq 0 ]]; then
  /usr/bin/osascript <<EOC
      tell app \"System Events\"
        display notification \"Dark Mode enabled.\rWelcome to the Dark.\" with title \"Slack Dark Mode\"
      end tell
EOC
else
  /usr/bin/osascript <<EOD
      tell app \"System Events\"
        display dialog \"There was some trouble enabling Dark Mode.\" with title \"Slack Dark Mode\" buttons {\"Ok\"} default button 1 with icon caution
      end tell
EOD
fi
# This is the magic part of the applescript to call the password dialog
" with prompt "Slack Dark Mode wants to make changes" with administrator privileges'