Testing

The mental model behind Rust's built-in test harness: how #[cfg(test)] modules, the tests/ directory, and doctests each answer a different question about correctness.

Learn Rust testing fundamentals with 10 examples. Understand #[test], assert! macros, should_panic, and how to run tests with cargo test.

Learn the differences between unit and integration tests in Rust, including when to use each, how to structure them, and see practical code examples.

Learn how to use Rust doctests to create executable documentation examples. Discover how to test public API examples and use doctest attributes.

Organize Rust tests for scalability by colocating unit tests, sharing integration fixtures, and managing setup for reliable parallel execution.

Learn how to use mockall to generate mock implementations for Rust traits, set call expectations, and verify interactions for external I/O boundaries.

Learn to implement snapshot testing in Rust using the insta crate. Capture and compare formatted output, manage snapshots, and redact unstable fields.

Learn to integrate cargo-llvm-cov into your Rust CI pipeline to measure test coverage, prevent regressions, and gate quality.

Learn Rust testing best practices for fast, deterministic, and meaningful tests. Structure tests, ensure determinism, and improve test quality.

A single-page roundup of every highlight bullet from the 12 pages in the Testing section, grouped by source page so you can scan all 68 takeaways without opening each article individually.