Number type (u16) field of struct throwing "invalid type: floating point 21010, expected u16"

[EliHarper]

Versions/Environment

1. What version of Rust are you using?
   1.71.1

2. What operating system are you using?
   Ubuntu 22.04.3 LTS x86_64

3. What versions of the driver and its dependencies are you using? (Run
   cargo pkgid mongodb & cargo pkgid bson)
   mongodb@2.6.1
   bson@2.6.1

4. What version of MongoDB are you using? (Check with the MongoDB shell using db.version())
   6.0.6

5. What is your MongoDB topology (standalone, replica set, sharded cluster, serverless)?
   replica set

Describe the bug

A u16 (port) field in a struct throws a deserialization error claiming that 21010 is a floating point number, rather than a u16.

Deserialization is triggered with a mongodb::cursor like it is performed in the mongodb docs.rs find example:

// Iterate over the results of the cursor.
while let Some(book) = cursor.try_next().await? {
    println!("title: {}", book.title);
}

I expected it to deserialize the struct with the u16 primitive type without issue.

• If you know how to reproduce this bug, please include a code snippet here:

#[derive(Debug, Serialize, Deserialize)]
struct Book {
    title: String,
    author: String,
    problem: u16,
}

...

// Query the books in the collection with a filter and an option.
let filter = doc! { "author": "George Orwell" };
let find_options = FindOptions::builder().sort(doc! { "title": 1 }).build();
let mut cursor = typed_collection.find(filter, find_options).await?;

// Iterate over the results of the cursor.
while let Some(book) = cursor.try_next().await? { # DeserializationError
    println!("title: {}", book.title);
}

[abr-egn]

Hi!

I can't reproduce the issue you're seeing. This test program

use bson::doc;
use mongodb::options::FindOptions;
use serde::{Serialize, Deserialize};
use futures::stream::TryStreamExt;

#[derive(Debug, Serialize, Deserialize)]
struct Book {
    title: String,
    author: String,
    problem: u16,
}

#[tokio::main]
async fn main() {
    let book = Book {
        title: "1984".to_string(),
        author: "George Orwell".to_string(),
        problem: 21010,
    };
    println!("original book:    {:?}", book);
    let bson_roundtrip: Book = bson::from_bson(bson::to_bson(&book).unwrap()).unwrap();
    println!("bson roundtrip:   {:?}", bson_roundtrip);
    let binary_roundtrip: Book = bson::from_reader(bson::to_vec(&book).unwrap().as_slice()).unwrap();
    println!("binary roundtrip: {:?}", binary_roundtrip);

    let client = mongodb::Client::with_uri_str("mongodb://localhost:27017").await.unwrap();
    let typed_collection = client.database("test_u16").collection::<Book>("test");
    typed_collection.drop(None).await.unwrap();
    typed_collection.insert_one(&book, None).await.unwrap();

    // Query the books in the collection with a filter and an option.
    let filter = doc! { "author": "George Orwell" };
    let find_options = FindOptions::builder().sort(doc! { "title": 1 }).build();
    let mut cursor = typed_collection.find(filter, find_options).await.unwrap();

    // Iterate over the results of the cursor.
    while let Some(book) = cursor.try_next().await.unwrap() {
        println!("title: {}", book.title);
    }
}

executes and prints

original book:    Book { title: "1984", author: "George Orwell", problem: 21010 }
bson roundtrip:   Book { title: "1984", author: "George Orwell", problem: 21010 }
binary roundtrip: Book { title: "1984", author: "George Orwell", problem: 21010 }
title: 1984

Please note that BSON, unlike JSON, distinguishes between integer and floating-point values; is it possible that the data you're trying to retrieve has this field stored as a float?

[EliHarper]

You're right! I apologize for the oversight.
Thanks so much for getting back to me!