How test if input change a value?

[dancespiele]

Question

is there any way to test if an input change a value? I have this test

#[wasm_bindgen_test]
fn should_write_a_text() {
    let mut console = ConsoleService::new();
    let oninput_event = Event::new("oninput").unwrap();

    struct WriteInput {
        link: ComponentLink<Self>,
        value: String,
    }

    enum MsgWriteInput {
        Input(String),
    }

    impl Component for WriteInput {
        type Message = MsgWriteInput;
        type Properties = ();
        fn create(_: Self::Properties, link: ComponentLink<Self>) -> Self {
            WriteInput {
                link,
                value: String::from(""),
            }
        }
        fn update(&mut self, msg: Self::Message) -> ShouldRender {
            match msg {
                MsgWriteInput::Input(value) => {
                    self.value = value;
                }
            };
            true
        }
        fn change(&mut self, _props: Self::Properties) -> ShouldRender {
            false
        }
        fn view(&self) -> Html {
            html! {
                <div>
                    <FormInput
                        input_type=InputType::Text
                        value=self.value.clone()
                        input_id="form-input-test"
                        oninput_signal=self.link.callback(|e: InputData| MsgWriteInput::Input(e.value))
                    />
                    <span id="result">{self.value.clone()}</span>
                </div>
            }
        }
    }

    let write_input: App<WriteInput> = App::new();

    write_input.mount(utils::document().get_element_by_id("output").unwrap());

    let input_element = utils::document()
        .get_element_by_id("form-input-test")
        .unwrap()
        .dyn_into::<HtmlInputElement>()
        .unwrap();

    input_element.set_form_target("hello");

    input_element.set_value("hello");

    input_element.dispatch_event(&oninput_event).unwrap();

    let target = input_element.form_target();

    console.log(&target);

    let span_element = utils::document().get_element_by_id("result").unwrap();

    assert_eq!(span_element.text_content().unwrap(), "hello".to_string());
}

It fail getting an empty string but I know that the component works because I tried it

[mc1098]

oninput is the wrong event name, it's just input (https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/input_event#javascript). I copied your example and adapted it for Yew v0.18.0 and it now works :)