object_transfer 2.0.0

//! A no-operation unsubscribe implementation.
//!
//! This module provides a no-op implementation of the unsubscribe trait,
//! useful for scenarios where unsubscribe operations are not needed or
//! should be skipped without performing any actual work.

use async_trait::async_trait;

use crate::errors::UnSubError;
use crate::traits::UnSubTrait;

/// A no-operation unsubscribe handler.
///
/// `UnSubNoop` is a simple implementation of [`UnSubTrait`]
/// that performs no operations when unsubscribe is called.
///
/// Depending on how it is configured, `unsubscribe` will either:
/// - Return `Ok(())` without taking any action when `should_err` is `false`
/// - Return `Err(UnSubError::NoHandler)` when `should_err` is `true`
///
/// This is useful for:
/// - Default implementations where unsubscribe is not required
/// - Testing and mocking scenarios
/// - Cases where subscription cleanup is not necessary
pub struct UnSubNoop {
  should_err: bool,
}

impl UnSubNoop {
  /// Creates a new instance of `UnSubNoop`.
  pub fn new(should_err: bool) -> Self {
    UnSubNoop { should_err }
  }
}

#[async_trait]
impl UnSubTrait for UnSubNoop {
  /// Performs a no-operation unsubscribe.
  ///
  /// Returns `Err(UnSubError::NoHandler)` if `should_err` is `true`,
  /// otherwise returns `Ok(())`.
  ///
  /// # Returns
  ///
  /// Returns `Err(UnSubError::NoHandler)` if `should_err` is `true`,
  /// otherwise returns `Ok(())`.
  async fn unsubscribe(&self) -> Result<(), UnSubError> {
    if self.should_err {
      return Err(UnSubError::NoHandler);
    }
    Ok(())
  }
}