complior-cli 1.0.1

/// Braille-based spinner for smooth loading animation.
const FRAMES: &[&str] = &["⠋", "⠙", "⠹", "⠸", "⠼", "⠴", "⠦", "⠧", "⠇", "⠏"];

pub struct Spinner {
    tick: usize,
}

impl Spinner {
    pub const fn new() -> Self {
        Self { tick: 0 }
    }

    pub const fn advance(&mut self) {
        self.tick = (self.tick + 1) % FRAMES.len();
    }

    pub fn frame(&self) -> &'static str {
        FRAMES[self.tick % FRAMES.len()]
    }
}

impl Default for Spinner {
    fn default() -> Self {
        Self::new()
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_spinner_cycles_all_10_frames() {
        let mut spinner = Spinner::new();
        assert_eq!(spinner.frame(), "⠋");
        for _ in 0..9 {
            spinner.advance();
        }
        assert_eq!(spinner.frame(), "⠏");
        spinner.advance();
        assert_eq!(spinner.frame(), "⠋"); // wraps
    }
}