Check Syntax Errors in JavaScript/JSX Files
- Ensure that there are no syntax errors in your JavaScript or JSX files. A common cause of the "unexpected token" error is a missing or misused punctuation mark or keyword.
- Review your code for unclosed brackets, parentheses, or other common syntax mistakes.
Update Babel Configurations
- Check if your Babel configuration is set up correctly in the root of your Next.js project. Make sure your
.babelrc or babel.config.json is configured properly.
- For example, your Babel configuration might look like the following:
{
"presets": ["next/babel"],
"plugins": []
}
Check for Unsupported JavaScript Features
- Verify that any JavaScript features you're using are supported by your Babel configuration. Some features might require additional Babel plugins or presets.
- If you use modern JavaScript syntax like optional chaining or nullish coalescing, make sure to install the necessary Babel plugins.
npm install @babel/plugin-proposal-optional-chaining
And include them in your Babel configuration:
{
"presets": ["next/babel"],
"plugins": ["@babel/plugin-proposal-optional-chaining"]
}
Resolve JSX Handling Errors
- If you encounter errors related to JSX, ensure your configuration includes
next/babel, which handles JSX out of the box.
- Ensure that you are correctly importing React in older versions where it’s necessary if you're using JSX:
import React from 'react';
Clear Babel Cache
- Sometimes stale cache in Babel can cause unexpected issues. Clear the cache to resolve potential conflicts:
rm -rf .next/cache
Check ESLint Configuration
- A misconfigured ESLint setup can also lead to parsing errors. Ensure that ESLint settings are properly configured to work with JSX and React.
- Verify your
.eslintrc.json or equivalent configuration file includes the React plugin:
{
"plugins": ["react"],
"extends": ["plugin:react/recommended"]
}
Update Dependencies
- Ensure all dependencies are up to date. Sometimes, mismatches can cause unexpected errors, including parsing issues in Babel.
- Use npm or yarn to upgrade all packages:
npm update
Check Node Version Compatibility
- Verify that your Node.js version is compatible with the Next.js and Babel version you are using. Using unsupported Node versions can lead to unexpected problems.
- Consider using a version manager like nvm to switch to a supported Node.js version:
nvm install 14
nvm use 14
