Rust Testing — mmap-guard#

Crate-specific delta only. Authoritative source: AGENTS.md + GOTCHAS.md.

Framework & commands#

• Prefer nextest: cargo nextest run (single test: cargo nextest run <name>).
  Fallback: cargo test. just test wraps this.
• proptest (stable) drives property tests and runs in the normal suite. The
  read_bounded proptest is a unit test inside src/load.rs because it needs the
  private function; tests/prop_map_file.rs covers map_file round-trips.
• cargo-fuzz (nightly) drives the fuzz/ targets (fuzz_read_bounded,
  fuzz_map_file). The __fuzz feature re-exports read_bounded for them. See
  GOTCHAS.md § Fuzzing — do not use __fuzz in library code.
• No async here → no #[tokio::test]. rstest/mockall are not used.

Coverage#

• cargo llvm-cov; the threshold is 85% (just coverage-check), not 80%.

Gotchas#

• Test modules need #[allow(clippy::unwrap_used, clippy::expect_used)] on the
  mod tests block (both are otherwise denied/warned).
• Do not call load("-") in unit tests — it reads real process stdin. Test the
  data path with read_bounded + a Cursor, and routing with resolve_source.
  See GOTCHAS.md § load / load_stdin.
• Permission tests (chmod 000 → PermissionDenied) false-pass as root — relevant
  under act. See GOTCHAS.md § Local CI with act.