[jacderida]

Rust 1.99 (released 2026-09-28) adds the pedantic clippy lint assert_is_empty, which this crate
picks up through its blanket pedantic = { level = "warn" }. CI runs with -D warnings, so
assert!(hashes.is_empty()) in payment::proof's tests now fails the clippy job — the same tree
passed clippy on 1.98.1.

The lint's point is that a bare assert! prints nothing useful when it fails; clippy's own
suggestion is assert_eq!(hashes, [] as [TxHash; 0]). A message carrying the value gives the same
diagnostic and reads better in a test, so that is what this uses.

One of four PRs for V2-1399, which sweeps the new toolchain's lints across the crates; the others
are in saorsa-transport, saorsa-core and ant-node. This repo had just the one site.

Linear issue

Closes V2-1399

Risk tier

• T0 — docs / tooling / CI / pure UX-output. Repo CI only.
• T1 — client-only, no network-facing behavior change. CI + prod compat smoke.
• T2 — node/client logic with behavioral surface, no protocol/format/economics change. Dev testnet + ADR.
• T3 — protocol / storage format / payments / routing. T2 evidence + adversarial testing.

Test-only change: one assertion in a #[cfg(test)] module gains a failure message.

Compatibility

• Wire: none
• Storage: none
• API: none

Semver impact

• breaking
• feature
• fix

Test evidence

T0: repo CI only. Run on 1.99.0 (b940084d7, 2026-09-28), the toolchain that produced the failure:

• cargo fmt --all -- --check — clean
• cargo clippy --all-targets --all-features -- -D warnings (the clippy job, verbatim) — clean
• cargo check --lib --no-default-features --target wasm32-unknown-unknown and the same with
  --features rpc (the WASM portability job) — clean

Test suites were not run locally; CI runs them on this PR. The assertion's condition is unchanged,
so test_payment_proof_with_empty_tx_hashes passes or fails exactly as before.

New dependency

none

ADR

n/a

Mitigation / rollback

Revert the commit.

🤖 Generated with Claude Code

[dirvine]

Approved after focused review of head 1fee1b1548da36ecde0e692a1e5be9af7c8e1a80. No blocking findings.

Test-only diagnostic addition. The empty-hashes assertion predicate is unchanged; hashes are formatted only on failure. CI checks, including Clippy, tests and WASM portability, pass.

Review scope: full PR diff and relevant source/API semantics, live CI and review-thread inspection, plus one lightweight GLM-5.2 independent cross-check (no full panel). No local crate build/test run; execution evidence is GitHub CI.