Draft `iced_test` crate and test `todos` example

18 files changed, 639 insertions, 62 deletions

diff --git a/Cargo.toml b/Cargo.toml
index fc38a89d..92687812 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -72,6 +72,7 @@ unconditional-rendering = ["iced_winit/unconditional-rendering"]
 iced_core.workspace = true
 iced_futures.workspace = true
 iced_renderer.workspace = true
+iced_test.workspace = true
 iced_widget.workspace = true
 iced_winit.features = ["program"]
 iced_winit.workspace = true
@@ -111,6 +112,7 @@ members = [
     "highlighter",
     "renderer",
     "runtime",
+    "test",
     "tiny_skia",
     "wgpu",
     "widget",
@@ -137,6 +139,7 @@ iced_graphics = { version = "0.14.0-dev", path = "graphics" }
 iced_highlighter = { version = "0.14.0-dev", path = "highlighter" }
 iced_renderer = { version = "0.14.0-dev", path = "renderer" }
 iced_runtime = { version = "0.14.0-dev", path = "runtime" }
+iced_test = { version = "0.14.0-dev", path = "test" }
 iced_tiny_skia = { version = "0.14.0-dev", path = "tiny_skia" }
 iced_wgpu = { version = "0.14.0-dev", path = "wgpu" }
 iced_widget = { version = "0.14.0-dev", path = "widget" }
diff --git a/core/src/keyboard/key.rs b/core/src/keyboard/key.rs
index 69a91902..47169d9a 100644
--- a/core/src/keyboard/key.rs
+++ b/core/src/keyboard/key.rs
@@ -32,6 +32,12 @@ impl Key {
     }
 }
 
+impl From<Named> for Key {
+    fn from(named: Named) -> Self {
+        Self::Named(named)
+    }
+}
+
 /// A named key.
 ///
 /// This is mostly the `NamedKey` type found in [`winit`].
diff --git a/core/src/widget/operation.rs b/core/src/widget/operation.rs
index 6bdb27f6..8fc627bf 100644
--- a/core/src/widget/operation.rs
+++ b/core/src/widget/operation.rs
@@ -30,24 +30,45 @@ pub trait Operation<T = ()>: Send {
     );
 
     /// Operates on a widget that can be focused.
-    fn focusable(&mut self, _state: &mut dyn Focusable, _id: Option<&Id>) {}
+    fn focusable(
+        &mut self,
+        _id: Option<&Id>,
+        _bounds: Rectangle,
+        _state: &mut dyn Focusable,
+    ) {
+    }
 
     /// Operates on a widget that can be scrolled.
     fn scrollable(
         &mut self,
-        _state: &mut dyn Scrollable,
         _id: Option<&Id>,
         _bounds: Rectangle,
         _content_bounds: Rectangle,
         _translation: Vector,
+        _state: &mut dyn Scrollable,
     ) {
     }
 
     /// Operates on a widget that has text input.
-    fn text_input(&mut self, _state: &mut dyn TextInput, _id: Option<&Id>) {}
+    fn text_input(
+        &mut self,
+        _id: Option<&Id>,
+        _bounds: Rectangle,
+        _state: &mut dyn TextInput,
+    ) {
+    }
+
+    /// Operates on a widget that contains some text.
+    fn text(&mut self, _id: Option<&Id>, _bounds: Rectangle, _text: &str) {}
 
     /// Operates on a custom widget with some state.
-    fn custom(&mut self, _state: &mut dyn Any, _id: Option<&Id>) {}
+    fn custom(
+        &mut self,
+        _id: Option<&Id>,
+        _bounds: Rectangle,
+        _state: &mut dyn Any,
+    ) {
+    }
 
     /// Finishes the [`Operation`] and returns its [`Outcome`].
     fn finish(&self) -> Outcome<T> {
@@ -68,33 +89,52 @@ where
         self.as_mut().container(id, bounds, operate_on_children);
     }
 
-    fn focusable(&mut self, state: &mut dyn Focusable, id: Option<&Id>) {
-        self.as_mut().focusable(state, id);
+    fn focusable(
+        &mut self,
+        id: Option<&Id>,
+        bounds: Rectangle,
+        state: &mut dyn Focusable,
+    ) {
+        self.as_mut().focusable(id, bounds, state);
     }
 
     fn scrollable(
         &mut self,
-        state: &mut dyn Scrollable,
         id: Option<&Id>,
         bounds: Rectangle,
         content_bounds: Rectangle,
         translation: Vector,
+        state: &mut dyn Scrollable,
     ) {
         self.as_mut().scrollable(
-            state,
             id,
             bounds,
             content_bounds,
             translation,
+            state,
         );
     }
 
-    fn text_input(&mut self, state: &mut dyn TextInput, id: Option<&Id>) {
-        self.as_mut().text_input(state, id);
+    fn text_input(
+        &mut self,
+        id: Option<&Id>,
+        bounds: Rectangle,
+        state: &mut dyn TextInput,
+    ) {
+        self.as_mut().text_input(id, bounds, state);
+    }
+
+    fn text(&mut self, id: Option<&Id>, bounds: Rectangle, text: &str) {
+        self.as_mut().text(id, bounds, text);
     }
 
-    fn custom(&mut self, state: &mut dyn Any, id: Option<&Id>) {
-        self.as_mut().custom(state, id);
+    fn custom(
+        &mut self,
+        id: Option<&Id>,
+        bounds: Rectangle,
+        state: &mut dyn Any,
+    ) {
+        self.as_mut().custom(id, bounds, state);
     }
 
     fn finish(&self) -> Outcome<O> {
@@ -150,33 +190,52 @@ where
             });
         }
 
-        fn focusable(&mut self, state: &mut dyn Focusable, id: Option<&Id>) {
-            self.operation.focusable(state, id);
+        fn focusable(
+            &mut self,
+            id: Option<&Id>,
+            bounds: Rectangle,
+            state: &mut dyn Focusable,
+        ) {
+            self.operation.focusable(id, bounds, state);
         }
 
         fn scrollable(
             &mut self,
-            state: &mut dyn Scrollable,
             id: Option<&Id>,
             bounds: Rectangle,
             content_bounds: Rectangle,
             translation: Vector,
+            state: &mut dyn Scrollable,
         ) {
             self.operation.scrollable(
-                state,
                 id,
                 bounds,
                 content_bounds,
                 translation,
+                state,
             );
         }
 
-        fn text_input(&mut self, state: &mut dyn TextInput, id: Option<&Id>) {
-            self.operation.text_input(state, id);
+        fn text_input(
+            &mut self,
+            id: Option<&Id>,
+            bounds: Rectangle,
+            state: &mut dyn TextInput,
+        ) {
+            self.operation.text_input(id, bounds, state);
         }
 
-        fn custom(&mut self, state: &mut dyn Any, id: Option<&Id>) {
-            self.operation.custom(state, id);
+        fn text(&mut self, id: Option<&Id>, bounds: Rectangle, text: &str) {
+            self.operation.text(id, bounds, text);
+        }
+
+        fn custom(
+            &mut self,
+            id: Option<&Id>,
+            bounds: Rectangle,
+            state: &mut dyn Any,
+        ) {
+            self.operation.custom(id, bounds, state);
         }
 
         fn finish(&self) -> Outcome<O> {
@@ -234,39 +293,55 @@ where
 
                 fn scrollable(
                     &mut self,
-                    state: &mut dyn Scrollable,
                     id: Option<&Id>,
                     bounds: Rectangle,
                     content_bounds: Rectangle,
                     translation: Vector,
+                    state: &mut dyn Scrollable,
                 ) {
                     self.operation.scrollable(
-                        state,
                         id,
                         bounds,
                         content_bounds,
                         translation,
+                        state,
                     );
                 }
 
                 fn focusable(
                     &mut self,
-                    state: &mut dyn Focusable,
                     id: Option<&Id>,
+                    bounds: Rectangle,
+                    state: &mut dyn Focusable,
                 ) {
-                    self.operation.focusable(state, id);
+                    self.operation.focusable(id, bounds, state);
                 }
 
                 fn text_input(
                     &mut self,
+                    id: Option<&Id>,
+                    bounds: Rectangle,
                     state: &mut dyn TextInput,
+                ) {
+                    self.operation.text_input(id, bounds, state);
+                }
+
+                fn text(
+                    &mut self,
                     id: Option<&Id>,
+                    bounds: Rectangle,
+                    text: &str,
                 ) {
-                    self.operation.text_input(state, id);
+                    self.operation.text(id, bounds, text);
                 }
 
-                fn custom(&mut self, state: &mut dyn Any, id: Option<&Id>) {
-                    self.operation.custom(state, id);
+                fn custom(
+                    &mut self,
+                    id: Option<&Id>,
+                    bounds: Rectangle,
+                    state: &mut dyn Any,
+                ) {
+                    self.operation.custom(id, bounds, state);
                 }
             }
 
@@ -275,33 +350,52 @@ where
             MapRef { operation }.container(id, bounds, operate_on_children);
         }
 
-        fn focusable(&mut self, state: &mut dyn Focusable, id: Option<&Id>) {
-            self.operation.focusable(state, id);
+        fn focusable(
+            &mut self,
+            id: Option<&Id>,
+            bounds: Rectangle,
+            state: &mut dyn Focusable,
+        ) {
+            self.operation.focusable(id, bounds, state);
         }
 
         fn scrollable(
             &mut self,
-            state: &mut dyn Scrollable,
             id: Option<&Id>,
             bounds: Rectangle,
             content_bounds: Rectangle,
             translation: Vector,
+            state: &mut dyn Scrollable,
         ) {
             self.operation.scrollable(
-                state,
                 id,
                 bounds,
                 content_bounds,
                 translation,
+                state,
             );
         }
 
-        fn text_input(&mut self, state: &mut dyn TextInput, id: Option<&Id>) {
-            self.operation.text_input(state, id);
+        fn text_input(
+            &mut self,
+            id: Option<&Id>,
+            bounds: Rectangle,
+            state: &mut dyn TextInput,
+        ) {
+            self.operation.text_input(id, bounds, state);
+        }
+
+        fn text(&mut self, id: Option<&Id>, bounds: Rectangle, text: &str) {
+            self.operation.text(id, bounds, text);
         }
 
-        fn custom(&mut self, state: &mut dyn Any, id: Option<&Id>) {
-            self.operation.custom(state, id);
+        fn custom(
+            &mut self,
+            id: Option<&Id>,
+            bounds: Rectangle,
+            state: &mut dyn Any,
+        ) {
+            self.operation.custom(id, bounds, state);
         }
 
         fn finish(&self) -> Outcome<B> {
@@ -361,33 +455,52 @@ where
             });
         }
 
-        fn focusable(&mut self, state: &mut dyn Focusable, id: Option<&Id>) {
-            self.operation.focusable(state, id);
+        fn focusable(
+            &mut self,
+            id: Option<&Id>,
+            bounds: Rectangle,
+            state: &mut dyn Focusable,
+        ) {
+            self.operation.focusable(id, bounds, state);
         }
 
         fn scrollable(
             &mut self,
-            state: &mut dyn Scrollable,
             id: Option<&Id>,
             bounds: Rectangle,
             content_bounds: Rectangle,
             translation: crate::Vector,
+            state: &mut dyn Scrollable,
         ) {
             self.operation.scrollable(
-                state,
                 id,
                 bounds,
                 content_bounds,
                 translation,
+                state,
             );
         }
 
-        fn text_input(&mut self, state: &mut dyn TextInput, id: Option<&Id>) {
-            self.operation.text_input(state, id);
+        fn text_input(
+            &mut self,
+            id: Option<&Id>,
+            bounds: Rectangle,
+            state: &mut dyn TextInput,
+        ) {
+            self.operation.text_input(id, bounds, state);
         }
 
-        fn custom(&mut self, state: &mut dyn std::any::Any, id: Option<&Id>) {
-            self.operation.custom(state, id);
+        fn text(&mut self, id: Option<&Id>, bounds: Rectangle, text: &str) {
+            self.operation.text(id, bounds, text);
+        }
+
+        fn custom(
+            &mut self,
+            id: Option<&Id>,
+            bounds: Rectangle,
+            state: &mut dyn Any,
+        ) {
+            self.operation.custom(id, bounds, state);
         }
 
         fn finish(&self) -> Outcome<B> {
diff --git a/core/src/widget/operation/focusable.rs b/core/src/widget/operation/focusable.rs
index 867c682e..8f66e575 100644
--- a/core/src/widget/operation/focusable.rs
+++ b/core/src/widget/operation/focusable.rs
@@ -32,7 +32,12 @@ pub fn focus<T>(target: Id) -> impl Operation<T> {
     }
 
     impl<T> Operation<T> for Focus {
-        fn focusable(&mut self, state: &mut dyn Focusable, id: Option<&Id>) {
+        fn focusable(
+            &mut self,
+            id: Option<&Id>,
+            _bounds: Rectangle,
+            state: &mut dyn Focusable,
+        ) {
             match id {
                 Some(id) if id == &self.target => {
                     state.focus();
@@ -64,7 +69,12 @@ pub fn count() -> impl Operation<Count> {
     }
 
     impl Operation<Count> for CountFocusable {
-        fn focusable(&mut self, state: &mut dyn Focusable, _id: Option<&Id>) {
+        fn focusable(
+            &mut self,
+            _id: Option<&Id>,
+            _bounds: Rectangle,
+            state: &mut dyn Focusable,
+        ) {
             if state.is_focused() {
                 self.count.focused = Some(self.count.total);
             }
@@ -104,7 +114,12 @@ where
     }
 
     impl<T> Operation<T> for FocusPrevious {
-        fn focusable(&mut self, state: &mut dyn Focusable, _id: Option<&Id>) {
+        fn focusable(
+            &mut self,
+            _id: Option<&Id>,
+            _bounds: Rectangle,
+            state: &mut dyn Focusable,
+        ) {
             if self.count.total == 0 {
                 return;
             }
@@ -147,7 +162,12 @@ where
     }
 
     impl<T> Operation<T> for FocusNext {
-        fn focusable(&mut self, state: &mut dyn Focusable, _id: Option<&Id>) {
+        fn focusable(
+            &mut self,
+            _id: Option<&Id>,
+            _bounds: Rectangle,
+            state: &mut dyn Focusable,
+        ) {
             match self.count.focused {
                 None if self.current == 0 => state.focus(),
                 Some(focused) if focused == self.current => state.unfocus(),
@@ -179,7 +199,12 @@ pub fn find_focused() -> impl Operation<Id> {
     }
 
     impl Operation<Id> for FindFocused {
-        fn focusable(&mut self, state: &mut dyn Focusable, id: Option<&Id>) {
+        fn focusable(
+            &mut self,
+            id: Option<&Id>,
+            _bounds: Rectangle,
+            state: &mut dyn Focusable,
+        ) {
             if state.is_focused() && id.is_some() {
                 self.focused = id.cloned();
             }
diff --git a/core/src/widget/operation/scrollable.rs b/core/src/widget/operation/scrollable.rs
index c2fecf56..7c78c087 100644
--- a/core/src/widget/operation/scrollable.rs
+++ b/core/src/widget/operation/scrollable.rs
@@ -39,11 +39,11 @@ pub fn snap_to<T>(target: Id, offset: RelativeOffset) -> impl Operation<T> {
 
         fn scrollable(
             &mut self,
-            state: &mut dyn Scrollable,
             id: Option<&Id>,
             _bounds: Rectangle,
             _content_bounds: Rectangle,
             _translation: Vector,
+            state: &mut dyn Scrollable,
         ) {
             if Some(&self.target) == id {
                 state.snap_to(self.offset);
@@ -74,11 +74,11 @@ pub fn scroll_to<T>(target: Id, offset: AbsoluteOffset) -> impl Operation<T> {
 
         fn scrollable(
             &mut self,
-            state: &mut dyn Scrollable,
             id: Option<&Id>,
             _bounds: Rectangle,
             _content_bounds: Rectangle,
             _translation: Vector,
+            state: &mut dyn Scrollable,
         ) {
             if Some(&self.target) == id {
                 state.scroll_to(self.offset);
@@ -109,11 +109,11 @@ pub fn scroll_by<T>(target: Id, offset: AbsoluteOffset) -> impl Operation<T> {
 
         fn scrollable(
             &mut self,
-            state: &mut dyn Scrollable,
             id: Option<&Id>,
             bounds: Rectangle,
             content_bounds: Rectangle,
             _translation: Vector,
+            state: &mut dyn Scrollable,
         ) {
             if Some(&self.target) == id {
                 state.scroll_by(self.offset, bounds, content_bounds);
diff --git a/core/src/widget/operation/text_input.rs b/core/src/widget/operation/text_input.rs
index 41731d4c..a46f1a2d 100644
--- a/core/src/widget/operation/text_input.rs
+++ b/core/src/widget/operation/text_input.rs
@@ -23,7 +23,12 @@ pub fn move_cursor_to_front<T>(target: Id) -> impl Operation<T> {
     }
 
     impl<T> Operation<T> for MoveCursor {
-        fn text_input(&mut self, state: &mut dyn TextInput, id: Option<&Id>) {
+        fn text_input(
+            &mut self,
+            id: Option<&Id>,
+            _bounds: Rectangle,
+            state: &mut dyn TextInput,
+        ) {
             match id {
                 Some(id) if id == &self.target => {
                     state.move_cursor_to_front();
@@ -53,7 +58,12 @@ pub fn move_cursor_to_end<T>(target: Id) -> impl Operation<T> {
     }
 
     impl<T> Operation<T> for MoveCursor {
-        fn text_input(&mut self, state: &mut dyn TextInput, id: Option<&Id>) {
+        fn text_input(
+            &mut self,
+            id: Option<&Id>,
+            _bounds: Rectangle,
+            state: &mut dyn TextInput,
+        ) {
             match id {
                 Some(id) if id == &self.target => {
                     state.move_cursor_to_end();
@@ -84,7 +94,12 @@ pub fn move_cursor_to<T>(target: Id, position: usize) -> impl Operation<T> {
     }
 
     impl<T> Operation<T> for MoveCursor {
-        fn text_input(&mut self, state: &mut dyn TextInput, id: Option<&Id>) {
+        fn text_input(
+            &mut self,
+            id: Option<&Id>,
+            _bounds: Rectangle,
+            state: &mut dyn TextInput,
+        ) {
             match id {
                 Some(id) if id == &self.target => {
                     state.move_cursor_to(self.position);
@@ -113,7 +128,12 @@ pub fn select_all<T>(target: Id) -> impl Operation<T> {
     }
 
     impl<T> Operation<T> for MoveCursor {
-        fn text_input(&mut self, state: &mut dyn TextInput, id: Option<&Id>) {
+        fn text_input(
+            &mut self,
+            id: Option<&Id>,
+            _bounds: Rectangle,
+            state: &mut dyn TextInput,
+        ) {
             match id {
                 Some(id) if id == &self.target => {
                     state.select_all();
diff --git a/core/src/widget/text.rs b/core/src/widget/text.rs
index d3d1cffd..5dd7892f 100644
--- a/core/src/widget/text.rs
+++ b/core/src/widget/text.rs
@@ -267,6 +267,18 @@ where
 
         draw(renderer, defaults, layout, state.0.raw(), style, viewport);
     }
+
+    fn operate(
+        &self,
+        _state: &mut Tree,
+        layout: Layout<'_>,
+        _renderer: &Renderer,
+        operation: &mut dyn super::Operation,
+    ) {
+        dbg!(&self.fragment);
+
+        operation.text(None, layout.bounds(), &self.fragment);
+    }
 }
 
 /// Produces the [`layout::Node`] of a [`Text`] widget.
diff --git a/examples/todos/Cargo.toml b/examples/todos/Cargo.toml
index 0d72be86..65c34a8f 100644
--- a/examples/todos/Cargo.toml
+++ b/examples/todos/Cargo.toml
@@ -26,6 +26,9 @@ uuid = { version = "1.0", features = ["js"] }
 web-sys = { workspace = true, features = ["Window", "Storage"] }
 wasm-timer.workspace = true
 
+[dev-dependencies]
+iced_test.workspace = true
+
 [package.metadata.deb]
 assets = [
     ["target/release-opt/todos", "usr/bin/iced-todos", "755"],
diff --git a/examples/todos/src/main.rs b/examples/todos/src/main.rs
index 25e3ead2..8772bb80 100644
--- a/examples/todos/src/main.rs
+++ b/examples/todos/src/main.rs
@@ -584,3 +584,36 @@ impl SavedState {
         Ok(())
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    use iced::test;
+    use iced::test::selector;
+
+    #[test]
+    fn it_creates_a_new_task() {
+        let (mut todos, _command) = Todos::new();
+        let _command = todos.update(Message::Loaded(Err(LoadError::File)));
+
+        let mut interface = test::interface(todos.view());
+
+        let _input = interface
+            .click("new-task")
+            .expect("new-task input must be present");
+
+        interface.typewrite("Create the universe");
+        interface.press_key(keyboard::key::Named::Enter);
+
+        for message in interface.into_messages() {
+            let _command = todos.update(message);
+        }
+
+        let mut interface = test::interface(todos.view());
+
+        let _ = interface
+            .find(selector::text("Create the universe"))
+            .expect("New task must be present");
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index 8f526cfd..d7628ea1 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -479,6 +479,7 @@ use iced_winit::runtime;
 
 pub use iced_futures::futures;
 pub use iced_futures::stream;
+pub use iced_test as test;
 
 #[cfg(feature = "highlighter")]
 pub use iced_highlighter as highlighter;
@@ -624,6 +625,7 @@ pub use error::Error;
 pub use event::Event;
 pub use executor::Executor;
 pub use font::Font;
+pub use program::Program;
 pub use renderer::Renderer;
 pub use settings::Settings;
 pub use task::Task;
diff --git a/test/Cargo.toml b/test/Cargo.toml
new file mode 100644
index 00000000..c09a196d
--- /dev/null
+++ b/test/Cargo.toml
@@ -0,0 +1,21 @@
+[package]
+name = "iced_test"
+version.workspace = true
+authors.workspace = true
+edition.workspace = true
+license.workspace = true
+repository.workspace = true
+homepage.workspace = true
+categories.workspace = true
+keywords.workspace = true
+rust-version.workspace = true
+
+[lints]
+workspace = true
+
+[dependencies]
+iced_runtime.workspace = true
+iced_tiny_skia.workspace = true
+
+iced_renderer.workspace = true
+iced_renderer.features = ["tiny-skia"]
diff --git a/test/src/lib.rs b/test/src/lib.rs
new file mode 100644
index 00000000..211ed4a2
--- /dev/null
+++ b/test/src/lib.rs
@@ -0,0 +1,296 @@
+//! Test your `iced` applications in headless mode.
+#![allow(missing_docs, missing_debug_implementations)]
+pub mod selector;
+
+pub use selector::Selector;
+
+use iced_renderer as renderer;
+use iced_runtime as runtime;
+use iced_runtime::core;
+use iced_tiny_skia as tiny_skia;
+
+use crate::core::clipboard;
+use crate::core::keyboard;
+use crate::core::mouse;
+use crate::core::widget;
+use crate::core::{Element, Event, Font, Pixels, Rectangle, Size, SmolStr};
+use crate::renderer::Renderer;
+use crate::runtime::user_interface;
+use crate::runtime::UserInterface;
+
+pub fn interface<'a, Message, Theme>(
+    element: impl Into<Element<'a, Message, Theme, Renderer>>,
+) -> Interface<'a, Message, Theme, Renderer> {
+    let mut renderer = Renderer::Secondary(tiny_skia::Renderer::new(
+        Font::default(),
+        Pixels(16.0),
+    ));
+
+    let raw = UserInterface::build(
+        element,
+        Size::new(1024.0, 1024.0),
+        user_interface::Cache::default(),
+        &mut renderer,
+    );
+
+    Interface {
+        raw,
+        renderer,
+        messages: Vec::new(),
+    }
+}
+
+pub struct Interface<'a, Message, Theme, Renderer> {
+    raw: UserInterface<'a, Message, Theme, Renderer>,
+    renderer: Renderer,
+    messages: Vec<Message>,
+}
+
+pub struct Target {
+    bounds: Rectangle,
+}
+
+impl<Message, Theme, Renderer> Interface<'_, Message, Theme, Renderer>
+where
+    Renderer: core::Renderer,
+{
+    pub fn find(
+        &mut self,
+        selector: impl Into<Selector>,
+    ) -> Result<Target, Error> {
+        let selector = selector.into();
+
+        match &selector {
+            Selector::Id(id) => {
+                struct FindById<'a> {
+                    id: &'a widget::Id,
+                    target: Option<Target>,
+                }
+
+                impl widget::Operation for FindById<'_> {
+                    fn container(
+                        &mut self,
+                        id: Option<&widget::Id>,
+                        bounds: Rectangle,
+                        operate_on_children: &mut dyn FnMut(
+                            &mut dyn widget::Operation<()>,
+                        ),
+                    ) {
+                        if self.target.is_some() {
+                            return;
+                        }
+
+                        if Some(self.id) == id {
+                            self.target = Some(Target { bounds });
+                            return;
+                        }
+
+                        operate_on_children(self);
+                    }
+
+                    fn scrollable(
+                        &mut self,
+                        id: Option<&widget::Id>,
+                        bounds: Rectangle,
+                        _content_bounds: Rectangle,
+                        _translation: core::Vector,
+                        _state: &mut dyn widget::operation::Scrollable,
+                    ) {
+                        if self.target.is_some() {
+                            return;
+                        }
+
+                        if Some(self.id) == id {
+                            self.target = Some(Target { bounds });
+                        }
+                    }
+
+                    fn text_input(
+                        &mut self,
+                        id: Option<&widget::Id>,
+                        bounds: Rectangle,
+                        _state: &mut dyn widget::operation::TextInput,
+                    ) {
+                        if self.target.is_some() {
+                            return;
+                        }
+
+                        if Some(self.id) == id {
+                            self.target = Some(Target { bounds });
+                        }
+                    }
+
+                    fn text(
+                        &mut self,
+                        id: Option<&widget::Id>,
+                        bounds: Rectangle,
+                        _text: &str,
+                    ) {
+                        if self.target.is_some() {
+                            return;
+                        }
+
+                        if Some(self.id) == id {
+                            self.target = Some(Target { bounds });
+                        }
+                    }
+
+                    fn custom(
+                        &mut self,
+                        id: Option<&widget::Id>,
+                        bounds: Rectangle,
+                        _state: &mut dyn std::any::Any,
+                    ) {
+                        if self.target.is_some() {
+                            return;
+                        }
+
+                        if Some(self.id) == id {
+                            self.target = Some(Target { bounds });
+                        }
+                    }
+                }
+
+                let mut find = FindById { id, target: None };
+
+                self.raw.operate(&self.renderer, &mut find);
+
+                find.target.ok_or(Error::NotFound(selector))
+            }
+            Selector::Text(text) => {
+                struct FindByText<'a> {
+                    text: &'a str,
+                    target: Option<Target>,
+                }
+
+                impl widget::Operation for FindByText<'_> {
+                    fn container(
+                        &mut self,
+                        _id: Option<&widget::Id>,
+                        _bounds: Rectangle,
+                        operate_on_children: &mut dyn FnMut(
+                            &mut dyn widget::Operation<()>,
+                        ),
+                    ) {
+                        if self.target.is_some() {
+                            return;
+                        }
+
+                        operate_on_children(self);
+                    }
+
+                    fn text(
+                        &mut self,
+                        _id: Option<&widget::Id>,
+                        bounds: Rectangle,
+                        text: &str,
+                    ) {
+                        if self.target.is_some() {
+                            return;
+                        }
+
+                        if self.text == text {
+                            self.target = Some(Target { bounds });
+                        }
+                    }
+                }
+
+                let mut find = FindByText { text, target: None };
+
+                self.raw.operate(&self.renderer, &mut find);
+
+                find.target.ok_or(Error::NotFound(selector))
+            }
+        }
+    }
+
+    pub fn click(
+        &mut self,
+        selector: impl Into<Selector>,
+    ) -> Result<Target, Error> {
+        let target = self.find(selector)?;
+
+        let _ = self.raw.update(
+            &[
+                Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Left)),
+                Event::Mouse(mouse::Event::ButtonReleased(mouse::Button::Left)),
+            ],
+            mouse::Cursor::Available(target.bounds.center()),
+            &mut self.renderer,
+            &mut clipboard::Null,
+            &mut self.messages,
+        );
+
+        Ok(target)
+    }
+
+    pub fn typewrite(&mut self, text: impl AsRef<str>) {
+        let events: Vec<_> = text
+            .as_ref()
+            .chars()
+            .map(|c| SmolStr::new_inline(&c.to_string()))
+            .flat_map(|c| {
+                key_press_and_release(
+                    keyboard::Key::Character(c.clone()),
+                    Some(c),
+                )
+            })
+            .collect();
+
+        let _ = self.raw.update(
+            &events,
+            mouse::Cursor::Unavailable,
+            &mut self.renderer,
+            &mut clipboard::Null,
+            &mut self.messages,
+        );
+    }
+
+    pub fn press_key(&mut self, key: impl Into<keyboard::Key>) {
+        let _ = self.raw.update(
+            &key_press_and_release(key, None),
+            mouse::Cursor::Unavailable,
+            &mut self.renderer,
+            &mut clipboard::Null,
+            &mut self.messages,
+        );
+    }
+
+    pub fn into_messages(self) -> impl IntoIterator<Item = Message> {
+        self.messages
+    }
+}
+
+fn key_press_and_release(
+    key: impl Into<keyboard::Key>,
+    text: Option<SmolStr>,
+) -> [Event; 2] {
+    let key = key.into();
+
+    [
+        Event::Keyboard(keyboard::Event::KeyPressed {
+            key: key.clone(),
+            modified_key: key.clone(),
+            physical_key: keyboard::key::Physical::Unidentified(
+                keyboard::key::NativeCode::Unidentified,
+            ),
+            location: keyboard::Location::Standard,
+            modifiers: keyboard::Modifiers::default(),
+            text,
+        }),
+        Event::Keyboard(keyboard::Event::KeyReleased {
+            key: key.clone(),
+            modified_key: key,
+            physical_key: keyboard::key::Physical::Unidentified(
+                keyboard::key::NativeCode::Unidentified,
+            ),
+            location: keyboard::Location::Standard,
+            modifiers: keyboard::Modifiers::default(),
+        }),
+    ]
+}
+
+#[derive(Debug, Clone)]
+pub enum Error {
+    NotFound(Selector),
+}
diff --git a/test/src/selector.rs b/test/src/selector.rs
new file mode 100644
index 00000000..54faa1a9
--- /dev/null
+++ b/test/src/selector.rs
@@ -0,0 +1,24 @@
+use crate::core::text;
+use crate::core::widget;
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum Selector {
+    Id(widget::Id),
+    Text(text::Fragment<'static>),
+}
+
+impl From<widget::Id> for Selector {
+    fn from(id: widget::Id) -> Self {
+        Self::Id(id)
+    }
+}
+
+impl From<&'static str> for Selector {
+    fn from(id: &'static str) -> Self {
+        Self::Id(widget::Id::new(id))
+    }
+}
+
+pub fn text(fragment: impl text::IntoFragment<'static>) -> Selector {
+    Selector::Text(fragment.into_fragment())
+}
diff --git a/widget/src/checkbox.rs b/widget/src/checkbox.rs
index 3686d34c..663bfad1 100644
--- a/widget/src/checkbox.rs
+++ b/widget/src/checkbox.rs
@@ -445,6 +445,16 @@ where
             );
         }
     }
+
+    fn operate(
+        &self,
+        _state: &mut Tree,
+        layout: Layout<'_>,
+        _renderer: &Renderer,
+        operation: &mut dyn widget::Operation,
+    ) {
+        operation.text(None, layout.bounds(), &self.label);
+    }
 }
 
 impl<'a, Message, Theme, Renderer> From<Checkbox<'a, Message, Theme, Renderer>>
diff --git a/widget/src/container.rs b/widget/src/container.rs
index d9740f72..a411a7d2 100644
--- a/widget/src/container.rs
+++ b/widget/src/container.rs
@@ -493,11 +493,11 @@ pub fn visible_bounds(id: Id) -> Task<Option<Rectangle>> {
     impl Operation<Option<Rectangle>> for VisibleBounds {
         fn scrollable(
             &mut self,
-            _state: &mut dyn widget::operation::Scrollable,
             _id: Option<&widget::Id>,
             bounds: Rectangle,
             _content_bounds: Rectangle,
             translation: Vector,
+            _state: &mut dyn widget::operation::Scrollable,
         ) {
             match self.scrollables.last() {
                 Some((last_translation, last_viewport, _depth)) => {
diff --git a/widget/src/scrollable.rs b/widget/src/scrollable.rs
index 41bb15f9..4188f67d 100644
--- a/widget/src/scrollable.rs
+++ b/widget/src/scrollable.rs
@@ -487,11 +487,11 @@ where
             state.translation(self.direction, bounds, content_bounds);
 
         operation.scrollable(
-            state,
             self.id.as_ref().map(|id| &id.0),
             bounds,
             content_bounds,
             translation,
+            state,
         );
 
         operation.container(
diff --git a/widget/src/text_editor.rs b/widget/src/text_editor.rs
index ffd06b77..ad852ce9 100644
--- a/widget/src/text_editor.rs
+++ b/widget/src/text_editor.rs
@@ -971,13 +971,13 @@ where
     fn operate(
         &self,
         tree: &mut widget::Tree,
-        _layout: Layout<'_>,
+        layout: Layout<'_>,
         _renderer: &Renderer,
         operation: &mut dyn widget::Operation,
     ) {
         let state = tree.state.downcast_mut::<State<Highlighter>>();
 
-        operation.focusable(state, None);
+        operation.focusable(None, layout.bounds(), state);
     }
 }
 
diff --git a/widget/src/text_input.rs b/widget/src/text_input.rs
index c3f0b25a..57ebe46a 100644
--- a/widget/src/text_input.rs
+++ b/widget/src/text_input.rs
@@ -617,14 +617,23 @@ where
     fn operate(
         &self,
         tree: &mut Tree,
-        _layout: Layout<'_>,
+        layout: Layout<'_>,
         _renderer: &Renderer,
         operation: &mut dyn Operation,
     ) {
         let state = tree.state.downcast_mut::<State<Renderer::Paragraph>>();
 
-        operation.focusable(state, self.id.as_ref().map(|id| &id.0));
-        operation.text_input(state, self.id.as_ref().map(|id| &id.0));
+        operation.focusable(
+            self.id.as_ref().map(|id| &id.0),
+            layout.bounds(),
+            state,
+        );
+
+        operation.text_input(
+            self.id.as_ref().map(|id| &id.0),
+            layout.bounds(),
+            state,
+        );
     }
 
     fn update(