exercises/07_threads/07_ack Issue: Type Mismatch in Test - Returning Option Instead of Ticket and Unwrap Usage

[RioCasanova]

Issue: Type Mismatch in Test - Returning Option<Ticket> Instead of Ticket and Unwrap Usage.

feel free to check my fork for this exercise: https://github.com/RioCasanova/100-exercises-to-learn-rust

Description:

The current implementation of the server code returns an Option<Ticket> from store.get(id) and sends it using the response_sender. However, the test expects the return type of the response_receiver to be a Ticket, not an Option<Ticket>. This mismatch causes a type error during compilation. Additionally, the test is calling .unwrap() on the Ticket, which doesn't align with the expected type handling.

The test is failing with the following error:

error[E0599]: no method named `unwrap` found for struct `Ticket` in the current scope
  --> exercises/07_threads/07_ack/tests/insert.rs:40:10
   |
   37 |       let ticket: Ticket = response_receiver
   |  __________________________-
   38 | |         .recv()
   | |          ------ method `unwrap` is available on `Result<Ticket, RecvError>`
   |  39 | |         .expect("No response received!")
   |  40 | |         .unwrap();
   |  |         -^^^^^^ method not found in `Ticket`
   |  |_________|

Problem:

1. The server code is sending an Option<Ticket> via the response_sender, but the test expects a Ticket. This causes a type mismatch and the error related to calling .unwrap() on an Option<Ticket>.
2. The test is calling .unwrap() on the Ticket, which causes an error because the receiver is not returning an Option<Ticket>, it should be returning Ticket directly.

Solution:

There are two key issues to address:

1. Server code should send a Ticket directly, not an Option<Ticket>. If store.get(id) returns Some(ticket), we should send that ticket. If None is returned, we can handle the case by logging an error, returning a default ticket, or another method of error handling.
2. The test code should not call .unwrap() on an Option<Ticket>. Since the server is expected to return a Ticket, the test code can directly receive the ticket, without unwrapping it.

Updated Server Code for the Command::Get Case:

Ok(Command::Get {
    id,
    response_sender,
}) => {
    // Retrieve the ticket by its ID
    match store.get(id) {
        Some(ticket) => {
            // Send the ticket back
            response_sender
                .send(ticket)
                .expect("Error sending ticket");
        }
        None => {
            // Handle the case where the ticket doesn't exist
            eprintln!("Ticket not found with ID: {:?}", id);
            // Optionally send a default ticket or handle the error as needed
        }
    }
}

Suggestion for Fixing the Test and Server Code:

Change the Command::Get sender type to Sender<Ticket> instead of Sender<Option<Ticket>> in the Command enum:

pub enum Command {
    Insert {
        draft: TicketDraft,
        response_sender: Sender<TicketId>,
    },
    Get {
        id: TicketId,
        response_sender: Sender<Ticket>,  // Change from Option<Ticket>
    },
}

In the test, you should no longer need to use .unwrap() because the server is returning a Ticket directly, not an Option<Ticket>. You can simply receive the Ticket from the receiver:

let ticket: Ticket = response_receiver
    .recv()
    .expect("No response received!");
assert_eq!(ticket_id, ticket.id);
assert_eq!(ticket.status, Status::ToDo);
assert_eq!(ticket.title, draft.title);
assert_eq!(ticket.description, draft.description);

Expected Behaviour:

The test should pass without errors, and the server will return a Ticket instead of an Option<Ticket>, resolving both the type mismatch and .unwrap() usage.

Steps to Reproduce:

1. Run the test with the current code.
2. Observe the compilation error related to .unwrap() on the Ticket type and the type mismatch when returning Option<Ticket>.
3. Implement the suggested solution to fix the type mismatch and re-run the test.

Expected Outcome:

The test should pass without errors, and the server code will correctly handle the received ticket, ensuring that .unwrap() is removed from the test code.