Features

• Improve sideEffects flag behavior when dynamic modules are part of the tree
  • Fixes a bug which causes empty modules (or type-only modules) to "break" Tree Shaking
• add splitChunks.enforceSizeThreshold to allow enfore splitting larger chunks unrelated from other limiations
  • Not set by default to avoid breaking change
  • It will be set by default to 50k in webpack 5
  • It's recommended to set it in webpack 4 too
• add support for resolve.roots and default resolve.roots: [context]
  • This allows to resolve server-relative urls (e.g. /src/abc) to the project root (or other locations when configured)
  • This allows to use loaders that rely on that behavior

Bugfixes

• fix bug where splitChunks produced non-optimal results when minSize is set to 0
  • This lead to NaNs in some places which breaks ordering
• Fix bug which lead to HMR not working for splitChunks in entrypoints
• force update watchpack and chokidar for chokidar bugfix which causes files to stop being watched