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tanu

tanu - High-performance and async-friendly WebAPI testing framework for Rust

6 releases (3 breaking)

new 0.4.0 Apr 21, 2025
0.3.2 Apr 3, 2025
0.3.1 Mar 17, 2025
0.2.0 Feb 17, 2025
0.1.0 Jan 30, 2025

#419 in Testing

Download history 91/week @ 2025-01-25 36/week @ 2025-02-01 1/week @ 2025-02-08 110/week @ 2025-02-15 14/week @ 2025-02-22 4/week @ 2025-03-01 127/week @ 2025-03-08 161/week @ 2025-03-15 227/week @ 2025-03-22 173/week @ 2025-03-29 319/week @ 2025-04-05 150/week @ 2025-04-12

874 downloads per month

Apache-2.0

3.5MB
3K SLoC

tanu

High-performance, async-friendly and ergonomic WebAPI testing framework for Rust

Motivation

As a long time backend engineer, I have always been passionate about building reliable and efficient systems. When working with WebAPIs, ensuring correctness, stability, and performance is crucial, yet I often found existing testing frameworks lacking in speed, flexibility, or Rust-native support. This led me to create a WebAPI testing framework in Rust.

While some WebAPI testing tools exist for Rust, they often lack ergonomics, are too low-level, or don't integrate well with modern Rust web frameworks. My goal was to create a framework that is:

  • Fast and lightweight – Leveraging Rust’s zero-cost abstractions to minimize unnecessary overhead.
  • Type-safe and ergonomic – Taking advantage of Rust’s strong type system to prevent common errors at compile time.
  • Easily extensible – Allowing developers to integrate custom assertions, mocking, and performance metrics seamlessly.
  • Concurrency and async-friendly – Supporting asynchronous requests and concurrent execution to test APIs efficiently.

I tried multiple solutions in the past but encountered significant limitations:

  • Postman - Postman is a great tool but not designed for API end-to-end testing. You need a GUI and have to write assertions in JavaScript, which results in massive JSON files that become difficult to manage.
  • Playwright - Playwright is an excellent framework for web end-to-end testing. While it does support API testing, I wanted to use the same language for both API implementation and tests, which Playwright does not offer.
  • Rust Standard Test Framework - I attempted multiple times to write API tests using #[test], along with tokio, test-case, and reqwest crates. While functional, this approach lacked structure and ergonomics for writing effective tests at scale. I wanted a dedicated framework to simplify and streamline the process.

Screenshots

Dependencies

~34–50MB
~665K SLoC