Javascript 如何确定双击（选定）的单词是否在范围内

我的contentarea中有此内容，希望切换所选文本的颜色。但Firefox和带有双击功能的edge chrome之间存在差异

$(".classWrapper").on("click",function(){
    let param=$(this).attr("data-param");
    let elementTag=$(this).attr("data-tag");
    let classes="";
    let result="";
    let text="";
    
    let sel = window.getSelection();
    
    let ranges = [];
    for(let i = 0; i < sel.rangeCount; i++) {
     ranges[i] = sel.getRangeAt(i);
    };  
    let range = sel.getRangeAt(0);
    let start = range.startOffset;
    let end = range.endOffset;      
    if (range > "" ) {
    
    
    let tagName=sel.anchorNode.parentNode.tagName;
    
    classNames=sel.anchorNode.parentNode.getAttribute("class");

    // firefox finds a DIV - although the word was surrounded with a SPAN
    // Chrome shows a SPAN - so i can do further things
    
    alert(tagName);

    if (tagName == "SPAN") {
      // i can remove or change the class
    }
})

Lorem ipsum dolor sit amet, <span class="text-danger">consectetur </span>adipisicing elit, sed do eiusmod hallo

Lorem ipsum <span class="text-danger"><span class="text-danger">dolor </span></span>sit amet, consectetur adipisicing elit, sed do eiusmod hallo

Lorem ipsum <span class="text-danger">dolor </span>sit amet, consectetur adipisicing elit, sed do eiusmod hallo

Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod hallo