📖 Description

webpack@5 depends on enhanced-resolve using a semver range (^5.x.x).

After upgrading (via fresh install / lockfile update), enhanced-resolve@5.21.0 gets installed, which introduces a breaking change in resolveContext.stack.

This breaks existing webpack plugins relying on resolver hooks.

🔁 Where the issue occurs

Custom plugin using:

resolver.hooks.resolved.tapAsync(
  pluginName,
  async (originalResolved, resolveContext, callback) => {
    // depends on resolveContext.stack
    callback();
  }
);

Behavior with enhanced-resolve 5.20.0

• resolveContext.stack is a Set
• Iterable and stable
• Works correctly for deduplication logic

Behavior with enhanced-resolve 5.21.0

resolveContext.stack is now an object:

{
  parent: {},
  path: '',
  module: true | false
}

⚠️ Issues Observed

• Breaking change in structure
  • Set → Object
  • Not iterable → breaks existing plugins
  • Inconsistent resolution metadata
• module flag missing or incorrect in some cases