schema-utils

Schema validation utility for webpack loaders, plugins, and other configuration objects. Version 4.3.3 is the latest stable release, actively maintained alongside webpack. It provides a validate() function that checks options against a JSON Schema, with clear error messages including the plugin/loader name and data path. Differentiates from generic validators like ajv by being tailored for webpack's configuration context, supporting post-formatting of errors and a configuration object for naming. Ships TypeScript types and has both ESM and CJS builds. Primarily used internally by webpack but also directly by custom loaders and plugins.