How I solved “Unchecked runtime.lastError” Error

I developed Edge extension and sideload it.

But there was an error.

How I solved the error?

I just added “return true;” at the end of the content script code to be injected.

chrome.runtime.onMessage.addListener(function(request, sender, sendResponse) {
    $("body").prepend(
        `<img  src="${request.url}" id="${request.imageDivId}"
               class="slide-image" /> `
    );
    $("head").prepend(
        `<style>
          .slide-image {
              height: auto;
              width: 100vw;
          }
        </style>`
    );
    $(`#${request.imageDivId}`).click(function() {
        $(`#${request.imageDivId}`).remove(`#${request.imageDivId}`);
    });
    sendResponse({ fromcontent: "This message is from content.js" });
    
    return true;
});

ChatGPT says the AddListener is not an ansync method, so this solution may not work. But it worked! I’m happy. I need to understand more about JavaScript.

Use Developer Tools for debugging

I’m really entry level developer for web development. Today I knew this “Developer Tools” is so useful for developing.

To get this, Go to … button > More Tools > Developer Tools.
I could see the image tag in Element section that is added in the extended script.