Question: How do you enable emmet for nextjs ( js file)?

Answer: 
Emmets don't work in JS files. However, you can set it so that VS Code thinks that it's a JSX file and it would give React IntelliSense.

1. Click the button written "JavaScript" in the Status Bar, which should be at the bottom.

[![enter image description here](https://i.stack.imgur.com/jUppw.png)](https://i.stack.imgur.com/jUppw.png)

2. Type "React" and select `react (javascriptreact)`.

[![enter image description here](https://i.stack.imgur.com/yCCpS.png)](https://i.stack.imgur.com/yCCpS.png)

3. After that, the file is set as a React file, and therefore, you can now use Emmets.

[![enter image description here](https://i.stack.imgur.com/ocvyj.png)](https://i.stack.imgur.com/ocvyj.png)

---

If you want all of your JS files to be set as React files, create `.vscode/settings.json` and paste this:

```json
{
  "files.associations": {
    "*.js": "javascriptreact"
  }
}

```
You can change the file extension from '.js' to '.jsx'