MediaWiki:Common.js

Note: After publishing, you may have to bypass your browser's cache to see the changes.

Firefox / Safari: Hold Shift while clicking Reload, or press either Ctrl-F5 or Ctrl-R (⌘-R on a Mac)
Google Chrome: Press Ctrl-Shift-R (⌘-Shift-R on a Mac)
Edge: Hold Ctrl while clicking Refresh, or press Ctrl-F5.

mw.loader.using( 'mediawiki.util', function () {
    const groups = mw.config.get( 'wgUserGroups' );

    const isPrivileged =
        groups.includes( 'editor' ) ||
        groups.includes( 'approver' ) ||
        groups.includes( 'sysop' );

    if ( !isPrivileged ) {
        mw.util.addCSS(
            `
            #ca-edit,
            #ca-edit-source,
            #ca-ve-edit,
            #ca-viewsource {
                display: none !important;
            }
            `
        );
    }
});