This is the unpublished documentation of wasm-bindgen, the published documentation is available on the main Rust and WebAssembly documentation site . Features documented here may not be available in released versions of wasm-bindgen.

Testing on wasm32-unknown-unknown with wasm-bindgen-test

The wasm-bindgen-test crate is an experimental test harness for Rust programs compiled to wasm using wasm-bindgen and the wasm32-unknown-unknown target.


  • Write tests for wasm as similar as possible to how you normally would write #[test]-style unit tests for native targets.

  • Run the tests with the usual cargo test command but with an explicit wasm target:

    cargo test --target wasm32-unknown-unknown