ryderfreeman4logos/cli-sub-agent/csa-test-gen

1. Write pure logic in core/ or domain/ module
2. Write unit tests for core logic
3. Verify all tests pass
4. Only THEN implement UI layer

#[cfg(test)]
mod tests {
    use super::*;
 
    // Naming: test_<function>_<scenario>_<expected>
    #[test]
    fn test_parse_valid_input_returns_expected() {
        // Arrange
        let input = "valid_input";
        // Act
        let result = parse(input);
        // Assert
        assert_eq!(result, expected_value);
    }
 
    #[test]
    fn test_parse_empty_input_returns_error() {
        let result = parse("");
        assert!(result.is_err());
    }
}

// Define trait abstraction
pub trait UserRepository {
    fn find(&self, id: &str) -> Option<User>;
}
 
// Test mock
#[cfg(test)]
struct MockUserRepository {
    users: HashMap<String, User>,
}
 
#[cfg(test)]
impl UserRepository for MockUserRepository {
    fn find(&self, id: &str) -> Option<User> {
        self.users.get(id).cloned()
    }
}

use proptest::prelude::*;
 
proptest! {
    #[test]
    fn prop_serialize_roundtrip(value in any::<MyType>()) {
        let serialized = serde_json::to_string(&value).unwrap();
        let deserialized: MyType = serde_json::from_str(&serialized).unwrap();
        prop_assert_eq!(value, deserialized);
    }
}

#![no_main]
use libfuzzer_sys::fuzz_target;
 
fuzz_target!(|data: &[u8]| {
    if let Ok(input) = std::str::from_utf8(data) {
        let _ = parse(input); // Should never panic
    }
});