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NEXTJS_MISSING_MODULARIZE_IMPORTS

modularizeImports can improve dev compilation speed for packages that use barrel files.
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Conformance is available on Enterprise plans

modularizeImports is a feature of Next 13 that can reduce dev compilation times when importing packages that are exported as barrel files. Barrel files are convenient ways to export code from a package from a single file to make it straightforward to import any of the code from the package. However, since they export a lot of code from the same file, importing these packages can cause tools to do a lot of additional work analyzing files that are unused in the application.

To fix this, you can add a modularizeImports config to next.config.js for the package that uses barrel files. For example:

next.config.js
modularizeImports: {
  lodash: {
    transform: 'lodash/{{member}}';
  }
}

The exact format of the transform may differ by package, so double check how the package uses barrel files first.

See the Next.js docs for more information.

You can also specify required modularizeImports config for your own packages.

In your conformance.config.jsonc file, add:

conformance.config.jsonc
NEXTJS_MISSING_MODULARIZE_IMPORTS: {
  requiredModularizeImports: [
    {
      moduleDependency: 'your-package-name',
      requiredConfig: {
        transform: 'your-package-name/{{member}}',
      },
    },
  ];
}

This will require that any workspace in your monorepo that uses the your-package-name package must use the provided modularizeImports config in their next.config.js file.

See Customizing Conformance for more information.

Last updated on February 22, 2024