Testing with wasm-bindgen-test - The `wasm-bindgen` Guide

# 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.

## Goals

- 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