Rollout and fix safety

This page centralizes rollout guidance used across rule migrations.

Phased rollout model

1. Start with warn severity to measure blast radius.
2. Run --fix only on a scoped folder first.
3. Review runtime-sensitive call sites manually.
4. Promote to error after baseline cleanup.

Fix safety expectations

• Autofix-safe patterns: simple API shape substitutions where runtime behavior is equivalent.
• Suggestion-only patterns: potentially behavior-sensitive changes requiring explicit reviewer choice.
• Manual migrations: replacements that depend on local typing, nullability, or control flow assumptions.

Manual verification checklist

1. Verify import changes are deduplicated and stable.
2. Confirm narrowed types still match downstream usage.
3. Validate guard/predicate behavior with tests.
4. Confirm no accidental semantic changes in edge cases.

FAQ

Why not migrate everything in one pass?

Large one-shot migrations make regressions harder to detect and review. Smaller batches isolate risk.

Should we always use --fix in CI?

No. Prefer running --fix locally and committing explicit changes. CI should validate, not rewrite, code.

How do we handle wrapper utilities?

Either align wrappers to canonical helpers/types used by this plugin or deprecate wrappers that duplicate behavior.