AppleScript: Graphic User Interface (GUI) Scripting(macosxautomation.com)

    tell application "TextEdit"
      tell document 1
        get first character of every word whose font is "Helvetica-Bold"  
      end tell
    end tell

    #!/usr/bin/env node

    const {app, its} = require('nodeautomation');

    const textedit = app('TextEdit');

    let doc = textedit.documents[0];

    let ref = doc.words.where(its.font.eq('Helvetica-Bold')).characters.first;

    console.log(ref.get());

    // => [ 'b', 'b', 'k' ]