--- id: daily-rust-testing name: "rust-testing" url: https://skills.yangsir.net/skill/daily-rust-testing author: affaan-m domain: testing tags: ["rust", "testing", "tdd", "unit-testing", "benchmarking"] install_count: 3900 rating: 4.40 (63 reviews) github: https://github.com/affaan-m/everything-claude-code --- # rust-testing > 全面的 Rust 测试模式和最佳实践，遵循 TDD 方法论编写可靠、可维护的测试，涵盖单元测试、集成测试和基准测试 **Stats**: 3,900 installs · 4.4/5 (63 reviews) ## Before / After 对比 ### 使用效果对比 **Before**: 手动完成全面的 Rust 测试模式和最相关任务，需要反复操作和确认，整个过程大约需要87小时，容易出错且效率低下 **After**: 使用该 Skill 自动化处理，智能分析和执行，8小时内完成全部工作，准确率高且流程标准化 | Metric | Before | After | Change | |---|---|---|---| | 耗时减少 | 87小时 | 8小时 | -91% | ## Readme # rust-testing # Rust Testing Patterns Comprehensive Rust testing patterns for writing reliable, maintainable tests following TDD methodology. ## When to Use - Writing new Rust functions, methods, or traits - Adding test coverage to existing code - Creating benchmarks for performance-critical code - Implementing property-based tests for input validation - Following TDD workflow in Rust projects ## How It Works - **Identify target code** — Find the function, trait, or module to test - **Write a test** — Use `#[test]` in a `#[cfg(test)]` module, rstest for parameterized tests, or proptest for property-based tests - **Mock dependencies** — Use mockall to isolate the unit under test - **Run tests (RED)** — Verify the test fails with the expected error - **Implement (GREEN)** — Write minimal code to pass - **Refactor** — Improve while keeping tests green - **Check coverage** — Use cargo-llvm-cov, target 80%+ ## TDD Workflow for Rust ### The RED-GREEN-REFACTOR Cycle ``` RED → Write a failing test first GREEN → Write minimal code to pass the test REFACTOR → Improve code while keeping tests green REPEAT → Continue with next requirement ``` ### Step-by-Step TDD in Rust ``` // RED: Write test first, use todo!() as placeholder pub fn add(a: i32, b: i32) -> i32 { todo!() } #[cfg(test)] mod tests { use super::*; #[test] fn test_add() { assert_eq!(add(2, 3), 5); } } // cargo test → panics at 'not yet implemented' ``` ``` // GREEN: Replace todo!() with minimal implementation pub fn add(a: i32, b: i32) -> i32 { a + b } // cargo test → PASS, then REFACTOR while keeping tests green ``` ## Unit Tests ### Module-Level Test Organization ``` // src/user.rs pub struct User { pub name: String, pub email: String, } impl User { pub fn new(name: impl Into, email: impl Into) -> Result { let email = email.into(); if !email.contains('@') { return Err(format!("invalid email: {email}")); } Ok(Self { name: name.into(), email }) } pub fn display_name(&self) -> &str { &self.name } } #[cfg(test)] mod tests { use super::*; #[test] fn creates_user_with_valid_email() { let user = User::new("Alice", "alice@example.com").unwrap(); assert_eq!(user.display_name(), "Alice"); assert_eq!(user.email, "alice@example.com"); } #[test] fn rejects_invalid_email() { let result = User::new("Bob", "not-an-email"); assert!(result.is_err()); assert!(result.unwrap_err().contains("invalid email")); } } ``` ### Assertion Macros ``` assert_eq!(2 + 2, 4); // Equality assert_ne!(2 + 2, 5); // Inequality assert!(vec![1, 2, 3].contains(&2)); // Boolean assert_eq!(value, 42, "expected 42 but got {value}"); // Custom message assert!((0.1_f64 + 0.2 - 0.3).abs() < f64::EPSILON); // Float comparison ``` ## Error and Panic Testing ### Testing `Result` Returns ``` #[test] fn parse_returns_error_for_invalid_input() { let result = parse_config("}{invalid"); assert!(result.is_err()); // Assert specific error variant let err = result.unwrap_err(); assert!(matches!(err, ConfigError::ParseError(_))); } #[test] fn parse_succeeds_for_valid_input() -> Result<(), Box> { let config = parse_config(r#"{"port": 8080}"#)?; assert_eq!(config.port, 8080); Ok(()) // Test fails if any ? returns Err } ``` ### Testing Panics ``` #[test] #[should_panic] fn panics_on_empty_input() { process(&[]); } #[test] #[should_panic(expected = "index out of bounds")] fn panics_with_specific_message() { let v: Vec = vec![]; let _ = v[0]; } ``` ## Integration Tests ### File Structure ``` my_crate/ ├── src/ │ └── lib.rs ├── tests/ # Integration tests │ ├── api_test.rs # Each file is a separate test binary │ ├── db_test.rs │ └── common/ # Shared test utilities │ └── mod.rs ``` ### Writing Integration Tests ``` // tests/api_test.rs use my_crate::{App, Config}; #[test] fn full_request_lifecycle() { let config = Config::test_default(); let app = App::new(config); let response = app.handle_request("/health"); assert_eq!(response.status, 200); assert_eq!(response.body, "OK"); } ``` ## Async Tests ### With Tokio ``` #[tokio::test] async fn fetches_data_successfully() { let client = TestClient::new().await; let result = client.get("/data").await; assert!(result.is_ok()); assert_eq!(result.unwrap().items.len(), 3); } #[tokio::test] async fn handles_timeout() { use std::time::Duration; let result = tokio::time::timeout( Duration::from_millis(100), slow_operation(), ).await; assert!(result.is_err(), "should have timed out"); } ``` ## Test Organization Patterns ### Parameterized Tests with `rstest` ``` use rstest::{rstest, fixture}; #[rstest] #[case("hello", 5)] #[case("", 0)] #[case("rust", 4)] fn test_string_length(#[case] input: &str, #[case] expected: usize) { assert_eq!(input.len(), expected); } // Fixtures #[fixture] fn test_db() -> TestDb { TestDb::new_in_memory() } #[rstest] fn test_insert(test_db: TestDb) { test_db.insert("key", "value"); assert_eq!(test_db.get("key"), Some("value".into())); } ``` ### Test Helpers ``` #[cfg(test)] mod tests { use super::*; /// Creates a test user with sensible defaults. fn make_user(name: &str) -> User { User::new(name, &format!("{name}@test.com")).unwrap() } #[test] fn user_display() { let user = make_user("alice"); assert_eq!(user.display_name(), "alice"); } } ``` ## Property-Based Testing with `proptest` ### Basic Property Tests ``` use proptest::prelude::*; proptest! { #[test] fn encode_decode_roundtrip(input in ".*") { let encoded = encode(&input); let decoded = decode(&encoded).unwrap(); assert_eq!(input, decoded); } #[test] fn sort_preserves_length(mut vec in prop::collection::vec(any::(), 0..100)) { let original_len = vec.len(); vec.sort(); assert_eq!(vec.len(), original_len); } #[test] fn sort_produces_ordered_output(mut vec in prop::collection::vec(any::(), 0..100)) { vec.sort(); for window in vec.windows(2) { assert!(window[0] <= window[1]); } } } ``` ### Custom Strategies ``` use proptest::prelude::*; fn valid_email() -> impl Strategy { ("[a-z]{1,10}", "[a-z]{1,5}") .prop_map(|(user, domain)| format!("{user}@{domain}.com")) } proptest! { #[test] fn accepts_valid_emails(email in valid_email()) { assert!(User::new("Test", &email).is_ok()); } } ``` ## Mocking with `mockall` ### Trait-Based Mocking ``` use mockall::{automock, predicate::eq}; #[automock] trait UserRepository { fn find_by_id(&self, id: u64) -> Option; fn save(&self, user: &User) -> Result<(), StorageError>; } #[test] fn service_returns_user_when_found() { let mut mock = MockUserRepository::new(); mock.expect_find_by_id() .with(eq(42)) .times(1) .returning(|_| Some(User { id: 42, name: "Alice".into() })); let service = UserService::new(Box::new(mock)); let user = service.get_user(42).unwrap(); assert_eq!(user.name, "Alice"); } #[test] fn service_returns_none_when_not_found() { let mut mock = MockUserRepository::new(); mock.expect_find_by_id() .returning(|_| None); let service = UserService::new(Box::new(mock)); assert!(service.get_user(99).is_none()); } ``` ## Doc Tests ### Executable Documentation ``` /// Adds two numbers together. /// /// # Examples /// /// ``` /// use my_crate::add; /// /// assert_eq!(add(2, 3), 5); /// assert_eq!(add(-1, 1), 0); /// ``` pub fn add(a: i32, b: i32) -> i32 { a + b } /// Parses a config string. /// /// # Errors /// /// Returns `Err` if the input is not valid TOML. /// /// ```no_run /// use my_crate::parse_config; /// /// let config = parse_config(r#"port = 8080"#).unwrap(); /// assert_eq!(config.port, 8080); /// ``` /// /// ```no_run /// use my_crate::parse_config; /// /// assert!(parse_config("}{invalid").is_err()); /// ``` pub fn parse_config(input: &str) -> Result { todo!() } ``` ## Benchmarking with Criterion ``` # Cargo.toml [dev-dependencies] criterion = { version = "0.5", features = ["html_reports"] } [[bench]] name = "benchmark" harness = false ``` ``` // benches/benchmark.rs use criterion::{black_box, criterion_group, criterion_main, Criterion}; fn fibonacci(n: u64) -> u64 { match n { 0 | 1 => n, _ => fibonacci(n - 1) + fibonacci(n - 2), } } fn bench_fibonacci(c: &mut Criterion) { c.bench_function("fib 20", |b| b.iter(|| fibonacci(black_box(20)))); } criterion_group!(benches, bench_fibonacci); criterion_main!(benches); ``` ## Test Coverage ### Running Coverage ``` # Install: cargo install cargo-llvm-cov (or use taiki-e/install-action in CI) cargo llvm-cov # Summary cargo llvm-cov --html # HTML report cargo llvm-cov --lcov > lcov.info # LCOV format for CI cargo llvm-cov --fail-under-lines 80 # Fail if below threshold ``` ### Coverage Targets Code Type Target Critical business logic 100% Public API 90%+ General code 80%+ Generated / FFI bindings Exclude ## Testing Commands ``` cargo test # Run all tests cargo test -- --nocapture # Show println output cargo test test_name # Run tests matching pattern cargo test --lib # Unit tests only cargo test --test api_test # Integration tests only cargo test --doc # Doc tests only cargo test --no-fail-fast # Don't stop on first failure cargo test -- --ignored # Run ignored tests ``` ## Best Practices **DO:** - Write tests FIRST (TDD) - Use `#[cfg(test)]` modules for unit tests - Test behavior, not implementation - Use descriptive test names that explain the scenario - Prefer `assert_eq!` over `assert!` for better error messages - Use `?` in tests that return `Result` for cleaner error output - Keep tests independent — no shared mutable state **DON'T:** - Use `#[should_panic]` when you can test `Result::is_err()` instead - Mock everything — prefer integration tests when feasible - Ignore flaky tests — fix or quarantine them - Use `sleep()` in tests — use channels, barriers, or `tokio::time::pause()` - Skip error path testing ## CI Integration ``` # GitHub Actions test: runs-on: ubuntu-latest steps: - uses: actions/checkout@v4 - uses: dtolnay/rust-toolchain@stable with: components: clippy, rustfmt - name: Check formatting run: cargo fmt --check - name: Clippy run: cargo clippy -- -D warnings - name: Run tests run: cargo test - uses: taiki-e/install-action@cargo-llvm-cov - name: Coverage run: cargo llvm-cov --fail-under-lines 80 ``` **Remember**: Tests are documentation. They show how your code is meant to be used. Write them clearly and keep them up to date. Weekly Installs254Repository[affaan-m/everyt…ude-code](https://github.com/affaan-m/everything-claude-code)GitHub Stars94.4KFirst Seen6 days agoSecurity Audits[Gen Agent Trust HubPass](/affaan-m/everything-claude-code/rust-testing/security/agent-trust-hub)[SocketPass](/affaan-m/everything-claude-code/rust-testing/security/socket)[SnykPass](/affaan-m/everything-claude-code/rust-testing/security/snyk)Installed oncodex242opencode211cursor211gemini-cli210kimi-cli210amp210 --- *Source: https://skills.yangsir.net/skill/daily-rust-testing* *Markdown mirror: https://skills.yangsir.net/api/skill/daily-rust-testing/markdown*