Consider Downstream API Impact

RUST-CONSIDER-DOWNSTREAM-API-IMPACT

Summary

Check public API changes against downstream imports, traits, inference, and examples before reshaping them. Additive paths and deprecations often avoid unnecessary breakage.

Rule

Consider downstream impact before changing public API.

Why

Changing a public Rust API can break external imports, trait impls, type inference, docs, examples, and semver expectations. Before renaming or replacing public items, consider additive APIs, deprecations, and external usage evidence.

Helps

Helps library maintainers avoid turning local cleanup into downstream breakage across imports, examples, trait impls, type inference, and semver expectations.

Limits

Breaking changes are sometimes correct when an API is unsound, misleading, or blocking important design repair. Make the break explicit and provide a migration path when possible.

Agent Instruction

Consider downstream impact before changing public API because changing a public Rust API can break
external imports, trait impls, type inference, docs, examples, and semver expectations.

Mechanisms

Prefer additive APIs, deprecations, compatibility shims, release notes, external usage searches, semver checks, and migration examples before removing or renaming public items.

References