我需要在特定字符记事本++之前和之后添加完全相同的文本

function addTextBeforeAndAfterSpecificCharacter(text, specificCharacter, addedText) {
  var index = text.indexOf(specificCharacter);
  if (index !== -1) {
    var beforeText = text.substring(0, index);
    var afterText = text.substring(index + 1);
    var newText = beforeText + specificCharacter + addedText + specificCharacter + afterText;
    return newText;
  } else {
    return text;
  }
}

var originalText = "This is a specific character test.";
var specificCharacter = "a";
var addedText = "added";

var newText = addTextBeforeAndAfterSpecificCharacter(originalText, specificCharacter, addedText);
console.log(newText);