![javascript file extension javascript file extension](https://miro.medium.com/max/1400/1*TeJb3sBvoF6tasJwDIbX8A.png)
The manifest.json file contains the metadata about the extension, such as name, description, permissions, etc., in the JSON format.
![javascript file extension javascript file extension](https://www.codegrepper.com/codeimages/node-js-check-if-file-exists-without-extension.png)
Include popup.html, main.js, style.css, and manifest.json for now. Create a separate folder for this project.
![javascript file extension javascript file extension](https://cdn4.iconfinder.com/data/icons/design-and-development-6-1/48/275-512.png)
#Javascript file extension how to
You can also cancel a running process by pressing F9. in JavaScript how to get the file name without extension, taking into consideration that a file name may contain dots. Let’s get started now and create a browser action extension. The custom validFileType() function takes a File object as a parameter, then uses () to check if any value in the fileTypes matches the file's type property. With 168k+ installs, this extension allows you to execute the current file or your selected code with Node.js by pressing F8 on your keyboard.