Limits on the Rollup onwarn Hook for Filtering Circular Dependency Warnings

Goal

Reduce notification noise in a Rollup build pipeline while preserving critical alerts. The onwarn hook allows selective suppression of warning messages such as circular dependencies, but the exact scope of suppression remains unclear.

Constraints

• The hook must call the provided warn() for warnings that should still surface.
• Suppressing too many codes may hide genuine bugs.
• Behavior may differ between Rollup 2.x and 3.x, and the interaction with the --silent flag is undocumented.

Unresolved Questions

1. Which warning codes are considered safe to suppress without compromising build integrity?
2. How does the onwarn hook behave when the --silent flag is used concurrently?
3. What is the effect of omitting the warn() call for a warning that should be retained?