eslint-rspack-plugin 5.0.0 Released as Pure ESM Package

Pure ESM Release

eslint-rspack-plugin, which integrates ESLint checks into Rspack compilation, has released version 5.0.0. The primary change in this release is its publication as a pure ESM (ECMAScript Module) package, with the removal of its CommonJS build.

Ecosystem Alignment

This shift to pure ESM aligns the plugin with the broader Rspack ecosystem, specifically mirroring Rspack 2.0. Rspack 2.0 also transitioned its core packages to pure ESM, dropping CommonJS builds to standardize module loading and conform to current Node.js practices. Most projects using the plugin via the JavaScript API should not require code changes, as Node.js 20 and later can load ESM modules using `require(esm)`.

Continued Functionality and Configuration

The plugin retains its core functionality, running ESLint as part of the build process and re-running checks only on changed files in watch mode. Configuration options carried into the 5.x line include caching (on by default), `configType` for ESLint config formats, `threads` for parallel linting, and `lintAllFiles` for comprehensive linting across multi-environment builds. Its configuration interface remains familiar to webpack users, as it was forked from `eslint-webpack-plugin`.

Performance Considerations and Alternatives

The project's README advises that running ESLint during the build can increase build times, suggesting a separate lint command for efficiency. This recommendation is also present in `@rsbuild/plugin-eslint` and the Rsbuild FAQ, which notes that Rsbuild does not run ESLint by default to protect compilation performance. The Rstack team now offers Rslint, a TypeScript-first, Go-written linter that claims 20 to 40 times faster linting than traditional ESLint setups, presenting a faster alternative for build speed optimization.