Install Slack black theme on macOS

install-slack-black.sh

#!/usr/bin/env bash
sudo mkdir -p /Library/Application\ Support/Slack/Resources
curl https://raw.githubusercontent.com/laCour/slack-night-mode/master/css/raw/black.css | sudo tee /Library/Application\ Support/Slack/Resources/black.css > /dev/null
sudo patch --backup /Applications/Slack.app/Contents/Resources/app.asar.unpacked/src/static/ssb-interop.js << EOF
*** ssb-interop.js
--- ssb-interop.js.patched
***************
*** 95,99 ****
    const mainModule = require.resolve('../ssb/main.ts');
    const isDevMode = loadSettings.devMode && isPrebuilt();
  
    init(resourcePath, mainModule, !isDevMode);
  }
--- 95,111 ----
    const mainModule = require.resolve('../ssb/main.ts');
    const isDevMode = loadSettings.devMode && isPrebuilt();
  
+   const fs = require('fs');
+   const blackCss = (() => {
+     try {
+       return fs.readFileSync('/Library/Application Support/Slack/Resources/black.css', { encoding: 'utf-8' });
+     } catch (err) {
+       return '';
+     }
+   })();
+   document.addEventListener('DOMContentLoaded', function() {
+     \$('<style></style>').appendTo('head').html(blackCss);
+   });
+
    init(resourcePath, mainModule, !isDevMode);
  }
EOF