Rust
Testing async Rust code requires an async runtime. Tokio provides the #[tokio::test] attribute macro that wraps your test in an async executor. This post covers patterns for testing futures, concurrent tasks, timeouts, and async traits. Basic Async Tests Use #[tokio::test] instead of #[test] for async test functions: #[tokio:
Rust
Tokio is Rust's most popular async runtime. Testing async Rust code requires a Tokio runtime to drive futures to completion. Tokio provides #[tokio::test] for exactly that. The Basics: #[tokio::test] Add tokio with the test feature to Cargo.toml: [dev-dependencies] tokio = { version = "1", features
Python
Testing async Python code requires an event loop to run coroutines. pytest-asyncio and anyio provide that infrastructure and make async tests look nearly identical to synchronous ones. The Problem with Async Tests You can't call await outside a coroutine, so this doesn't work: # Won'
JavaScript
Async JavaScript is everywhere — fetch calls, timers, event handlers, database queries. Testing async code correctly requires understanding how the JavaScript event loop works and how Jest and Vitest provide tools to control it. Async Test Functions Both Jest and Vitest support async/await in test functions natively: // Jest or Vitest