rust-testing-strategylisted

## Outcome Produce a repository-aligned Rust test plan or implementation in which each behavior is proven at the narrowest trustworthy boundary, asynchronous behavior is deterministic, live dependencies are explicitly authorized and isolated, and reported evidence distinguishes executed checks from proposed coverage. ## Compatibility Portable across Claude Code, Codex, and OpenCode. Follow the target repository's Rust toolchain, edition, MSRV, workspace, features, lockfile policy, test runner, CI, and fixture conventions; Edition 2024 examples require Rust 1.85 or newer. Templates are adaptable snippets and do not authorize new dev-dependencies. Network/container tests are optional and require explicit authority, available infrastructure, isolated credentials, and cleanup. Native-client compatibility remains unverified until a validated report records the client version and exact source SHA. ## Use this skill when - Deciding whether a behavior needs a unit, integration, doctest, binary-smoke, or end-to-end test. - Moving tests to the correct crate/process boundary or removing production-only test shims. - Making async, timer, filesystem, environment, concurrency, or failure tests deterministic. - Designing authorized tests against databases, brokers, containers, or external services. ## Do not use this skill when - The primary output is public API prose, intra-doc links, examples, or rustdoc lints; use `rustdoc-maintenance`. - General task ownership, cancellation, or