More and more npm packages are shipping as ESM. In node, the compatibility between ESM and CommonJS has some limitation:

• an ES module can import a CommonJS module
• an ES module can dynamically import a CommonJS module
• a CommonJS module cannot import an ES module (Node 22 has anexperimental feature allowing it for synchronous object graphs, i.e. ES modules that don't use top-level await)
• a CommonJS module can dynamically import an ES module throughawait import(...) (but this can only be used in an async context)

Shipping Encore as a CommonJS module means that we cannot upgrade our dependencies to versions that have migrated to ESM (asEncore.getConfig() is a synchronous API, any solution requiring an async context is a no-go).

Migrating to ESM needs to be done in a new major version as it is a BC break for downstream projects. This will require writing thewebpack.config.js file in ESM, either by usingtype=module in the package.json or by usingwebpack.config.mjs instead (which is supported by webpack)