Unit testing

Unit testing can be done by using the `Dom::assert_eq` function, which tests your DOM against a certain XML string: ```rust struct DataModel; fn render_counter(count: usize) -> Dom { Dom::div().with_class("test").with_child( Dom::label(format!("{}", count)) ) } #[test] fn test_counter_ui() { let expected = r#"


"#; let dom = render_counter(5); dom.assert_eq(expected); } ``` You can technically also use `assert_eq!(expected, got);`, however, if the test fails, the `Dom::assert_eq` error message has a much nicer format: ```xml thread 'widgets::test_counter_ui' panicked at ' Expected DOM did not match: expected: ----------


got: ----------


``` ## Good Practices - Typedef the name of your DataModel in your main.rs, so that it it easier to change in future projects. - It's also a good idea to typedef the `&'a AppState` and the `&'a mut CallbackInfo`, in order to keep the code cleaner: ```rust pub type DataModel = AppData; pub type State<'a> = &'a mut AppState; pub type CbInfo<'a, 'b> = &'a mut CallbackInfo<'b, DataModel>; ``` This way you can avoid a bit of typing work since rustc is smart enough to infer the lifetimes - your callbacks should now look like this: ```rust fn my_callback(state: State, cb: CbInfo) -> Dom { /* */ } ```