Module testing 

A headless driver for an App: clicks, keys, typed text and drags through the real view and on_event, with no window and no GPU.

Drive owns (or borrows) a Core and a viewport. A test frames the app, finds nodes by the label they were keyed under, sends gestures and reads back what the frame drew. It runs under plain cargo test.

use kui_native::testing::Drive;
use kui_native::widgets;
use kui_native::{App, Core, Message, NodeSpec, TextStyle, Ui, UiEvent};

#[derive(Message, Clone, Debug, PartialEq)]
enum Msg {
    Add,
}

#[derive(Default)]
struct Counter {
    count: u32,
}

impl App for Counter {
    fn view(&mut self, ui: &mut Ui<'_>) {
        ui.with(NodeSpec::column().fill().gap(8.0), |ui| {
            widgets::button(ui, "Add", Msg::Add);
            ui.text_in_keyed(
                "summary",
                NodeSpec::row(),
                &format!("{} added", self.count),
                TextStyle::new(12.0),
            );
        });
    }

    fn on_event(&mut self, ev: UiEvent) {
        if ev.message::<Msg>() == Some(Msg::Add) {
            self.count += 1;
        }
    }
}

let mut app = Counter::default();
// `framing` builds a frame after every gesture, so the view has caught
// up before the next assert.
let mut d = Drive::new(Core::new(), 320.0, 200.0).framing();
d.frame(&mut app);

// Click by label, the way a screen reader presses: no geometry needed.
let add = d.key_of("Add").expect("an Add button");
d.click_key(&mut app, add);
assert_eq!(app.count, 1);
assert_eq!(d.texts_under("summary"), ["1 added"]);
// Nothing the core saw was misdeclared.
assert!(d.warnings().is_empty());

Without Drive::framing, a gesture sends its inputs and stops, and the test calls Drive::frame when it wants the view to catch up. Events reach the app as the windowed runner sends them: an extension’s to the extension, the rest to on_event, each one logged (Drive::log).

Structs

Drive

The headless driver; see the module docs for an example.