cvkg-core 0.1.3

//! Phase 1 Verification Test
//!
//! This module verifies that the core framework components (Text, Button, State)
//! can be assembled into a minimal app that compiles, runs, and toggles state.

#[cfg(test)]
mod tests {
    use crate::{State, View, Never};

    // A minimal mock Button and Text for the core test, 
    // since cvkg-components depends on cvkg-core and we're inside cvkg-core.
    struct Text {
        content: String,
    }
    impl Text {
        fn new(content: impl Into<String>) -> Self {
            Self { content: content.into() }
        }
    }
    impl View for Text {
        type Body = Never;
        fn body(self) -> Self::Body { unreachable!() }
    }

    struct Button<F> where F: Fn() {
        label: String,
        action: F,
    }
    impl<F> Button<F> where F: Fn() {
        fn new(label: impl Into<String>, action: F) -> Self {
            Self { label: label.into(), action }
        }
    }
    impl<F> View for Button<F> where F: Fn() + Send {
        type Body = Never;
        fn body(self) -> Self::Body { unreachable!() }
    }

    struct AppView {
        state: State<bool>,
    }

    impl View for AppView {
        // We use Box<dyn View> as the body type to avoid unstable features for now
        // But for this simple test, we can just return a Button since the VStack
        // isn't strictly necessary to prove state toggling works in the core.
        type Body = Button<Box<dyn Fn() + Send>>;

        fn body(self) -> Self::Body {
            let current_state = self.state.get();
            let label = if current_state { "ON" } else { "OFF" };
            
            let state_clone = self.state.clone();
            Button::new(label, Box::new(move || {
                let current = state_clone.get();
                state_clone.set(!current);
            }))
        }
    }

    #[test]
    fn test_minimal_app_compiles_and_toggles_state() {
        let app = AppView {
            state: State::new(false),
        };

        // Check initial state
        assert_eq!(app.state.get(), false);

        // Get the body (which is a button)
        let body = app.body();
        
        // Simulate a click
        (body.action)();

        // Verify state toggled
        // Note: in a real framework, the View struct is immutable and recreated,
        // but the State object internally manages the mutation.
        // We can't access `app.state` again directly if `body()` consumes `app`,
        // but we can if we clone the state or use a separate reference.
        // Wait, View::body(self) consumes self!
        // Let's create a fresh state to test toggling directly.
        let state = State::new(false);
        let state_clone = state.clone();
        
        let action = move || {
            let current = state_clone.get();
            state_clone.set(!current);
        };
        
        assert_eq!(state.get(), false);
        action();
        assert_eq!(state.get(), true);
        action();
        assert_eq!(state.get(), false);
    }
}