ui-agregator/crates/evil-keys/tests/proptest_invariants.rs

use crossterm::event::{KeyCode, KeyEvent, KeyEventKind, KeyEventState, KeyModifiers};
use evil_keys::key::{parse_key, parse_sequence};
use evil_keys::{DispatchResult, Dispatcher, Key, KeyTrie};
use proptest::prelude::*;

fn valid_key_string() -> impl Strategy<Value = String> {
    prop_oneof![
        prop::char::range('a', 'z').prop_map(|c| c.to_string()),
        prop::char::range('A', 'Z').prop_map(|c| c.to_string()),
        prop::char::range('0', '9').prop_map(|c| c.to_string()),
        Just("SPC".to_string()),
        Just("Esc".to_string()),
        Just("Tab".to_string()),
        Just("Enter".to_string()),
        Just("-".to_string()),
        Just("[".to_string()),
        Just("]".to_string()),
        Just("/".to_string()),
        Just("?".to_string()),
        (1u8..=12).prop_map(|n| format!("F{n}")),
        prop::char::range('a', 'z').prop_map(|c| format!("C-{c}")),
    ]
}

fn test_dispatcher() -> Dispatcher<&'static str> {
    let mut trie = KeyTrie::new("normal");
    trie.bind("j", "down").unwrap();
    trie.bind("k", "up").unwrap();
    trie.bind("Esc", "escape").unwrap();
    trie.group("g", "+goto", |g| {
        g.bind("g", "goto_first")?;
        g.bind("t", "next_tab")?;
        Ok(())
    })
    .unwrap();

    let mut d = Dispatcher::new();
    d.add_mode("normal", trie).unwrap();
    d.set_active("normal").unwrap();
    d
}

fn press(code: KeyCode) -> KeyEvent {
    KeyEvent {
        code,
        modifiers: KeyModifiers::NONE,
        kind: KeyEventKind::Press,
        state: KeyEventState::NONE,
    }
}

fn press_char(c: char) -> KeyEvent {
    press(KeyCode::Char(c))
}

proptest! {
    #[test]
    fn key_parse_display_roundtrip(s in valid_key_string()) {
        let key = parse_key(&s).unwrap();
        let displayed = key.to_string();
        let reparsed = parse_key(&displayed).unwrap();
        prop_assert_eq!(key, reparsed);
    }

    #[test]
    fn key_parse_never_panics(s in "\\PC{0,20}") {
        let _ = parse_key(&s);
    }

    #[test]
    fn key_display_never_panics(c in any::<char>().prop_filter("ascii", |c| c.is_ascii() && !c.is_control())) {
        let key = Key { code: KeyCode::Char(c), modifiers: KeyModifiers::NONE };
        let _ = key.to_string();
    }

    #[test]
    fn non_press_always_ignored(code_char in prop::char::range('a', 'z')) {
        let mut d = test_dispatcher();
        let release = KeyEvent {
            code: KeyCode::Char(code_char),
            modifiers: KeyModifiers::NONE,
            kind: KeyEventKind::Release,
            state: KeyEventState::NONE,
        };
        prop_assert_eq!(d.dispatch(release), DispatchResult::Ignored);

        let repeat = KeyEvent {
            code: KeyCode::Char(code_char),
            modifiers: KeyModifiers::NONE,
            kind: KeyEventKind::Repeat,
            state: KeyEventState::NONE,
        };
        prop_assert_eq!(d.dispatch(repeat), DispatchResult::Ignored);
    }

    #[test]
    fn count_take_always_at_least_1(digits in prop::collection::vec(prop::char::range('1', '9'), 0..10)) {
        let mut count = evil_keys::count::CountState::new();
        for d in digits {
            count.push_digit(d);
        }
        prop_assert!(count.take() >= 1);
    }

    #[test]
    fn escape_always_clears_pending(keys_before in prop::collection::vec(prop::char::range('a', 'z'), 0..5)) {
        let mut d = test_dispatcher();
        for c in keys_before {
            let _ = d.dispatch(press_char(c));
        }
        let _ = d.dispatch(press(KeyCode::Esc));
        prop_assert!(d.pending_keys().is_empty());
    }

    #[test]
    fn trie_bound_keys_always_found(keys in prop::collection::vec(valid_key_string(), 1..10)) {
        let mut trie: KeyTrie<usize> = KeyTrie::new("test");
        let mut successful = vec![];

        for (i, key) in keys.iter().enumerate() {
            if trie.bind(key, i).is_ok() {
                successful.push(key.clone());
            }
        }

        for key in &successful {
            let seq = parse_sequence(key).unwrap();
            prop_assert!(matches!(
                trie.search(&seq),
                evil_keys::SearchResult::Found(_)
            ));
        }
    }

    #[test]
    fn search_empty_trie_never_panics(keys in prop::collection::vec(valid_key_string(), 0..5)) {
        let trie: KeyTrie<()> = KeyTrie::new("test");
        let parsed: Vec<Key> = keys
            .iter()
            .filter_map(|k| parse_key(k).ok())
            .collect();
        let _ = trie.search(&parsed);
    }
}