let msgInpt = document.getElementById("message");
msgInpt.addEventListener("keydown", function(entEvt){
    if (!msgInpt.innerText === ' ') {
        if (entEvt.code === 'Enter' && !entEvt.shiftKey) {
            entEvt.preventDefault();
            postChat();
        }
    } else {
        if (entEvt.code === 'Enter' && !entEvt.shiftKey) {
           entEvt.preventDefault();
           return false;
        } else if(entEvt.code === 'Enter' && entEvt.shiftKey) {
            entEvt.preventDefault();
            return false;
        } else if (entEvt.code === 'Space') {
            entEvt.preventDefault();
            return false;
        }
    }
});

div{
  background-color: #f2f2f4;
  padding: 12px;
  height: 150px;
  border: 2px solid #333;
  border-radius: 10px;
  box-shadow: 0px 0px 12px 4px rgba(0,0,0,0.18);
}

<div contenteditable="true" id="message"></div>

After that I tried this

msgInpt.addEventListener("keydown", function(entEvt){
    if (msgInpt.innerText) {
        if (entEvt.code === 'Enter' && !entEvt.shiftKey) {
            entEvt.preventDefault();
            if (!msgInpt.innerText === ' ') {
                postChat();
            }
        }
    } else {
        if (entEvt.code === 'Enter' && !entEvt.shiftKey) {
           entEvt.preventDefault();
           return false;
        } else if(entEvt.code === 'Enter' && entEvt.shiftKey) {
            entEvt.preventDefault();
            return false;
        } else if (entEvt.code === 'Space') {
            entEvt.preventDefault();
            return false;
        }
    }
});

I want to validate whether the user is giving input as word only. When user First gives input of or \n only, then user must not be able to send messages.

Why Both the codes are not working?

Please can anybody tell me what is the logic behind this