# CLEAN: deno

Scanned 2026-03-30. No actionable CWE-407 defects found.

The Deno codebase uses correct data structures throughout:
- `HashSet` for deduplication and membership tests (module_loader.rs, permissions/lib.rs, etc.)
- `BTreeSet` for sorted membership (cli/util/extract.rs)
- `HashMap`/`BTreeMap` for O(1) keyed lookups
- Fixed-size array literals only for small constant-size checks

No `Vec.contains()` patterns found in performance-critical loops.