Highlight attachment file

Using RegEx replace with callback function

  const attachmentRex = /(?:Attachment[:\s]*)(.*)/gm;
  msg.emailBody = msg.emailBody.replace(attachmentRex, (original, matched, index)=>{
    let docIndex = this.searchAttachment(matched);
    let attachmentPrex = original.split(' ')[0];
    return attachmentPrex + ' <span id="attachmentDiv" class="attachment-highlight" onmouseenter="showPreview(event,'+docIndex+')">' + matched +'</span>';
  });