crates/serde_test/README.md

# serde\_test   [![Build Status]][actions] [![Latest Version]][crates.io]

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[crates.io]: https://crates.io/crates/serde\_test

This crate provides a convenient concise way to write unit tests for
implementations of [`Serialize`] and [`Deserialize`].

[`Serialize`]: serde::ser::Serialize
[`Deserialize`]: serde::de::Deserialize

The `Serialize` impl for a value can be characterized by the sequence of
[`Serializer`] calls that are made in the course of serializing the value, so
`serde_test` provides a [`Token`] abstraction which corresponds roughly to
`Serializer` method calls. There is an [`assert_ser_tokens`] function to test
that a value serializes to a particular sequence of method calls, an
[`assert_de_tokens`] function to test that a value can be deserialized from a
particular sequence of method calls, and an [`assert_tokens`] function to test
both directions. There are also functions to test expected failure conditions.

[`Serializer`]: serde::ser::Serializer

Here is an example from the [`linked-hash-map`] crate.

[`linked-hash-map`]: https://github.com/contain-rs/linked-hash-map

```rust
use linked_hash_map::LinkedHashMap;
use serde_test::{assert_tokens, Token};

#[test]
fn test_ser_de_empty() {
    let map = LinkedHashMap::<char, u32>::new();

    assert_tokens(
        &map,
        &[
            Token::Map { len: Some(0) },
            Token::MapEnd,
        ],
    );
}

#[test]
fn test_ser_de() {
    let mut map = LinkedHashMap::new();
    map.insert('b', 20);
    map.insert('a', 10);
    map.insert('c', 30);

    assert_tokens(
        &map,
        &[
            Token::Map { len: Some(3) },
            Token::Char('b'),
            Token::I32(20),
            Token::Char('a'),
            Token::I32(10),
            Token::Char('c'),
            Token::I32(30),
            Token::MapEnd,
        ],
    );
}
```

<br>

#### License

<sup>
Licensed under either of <a href="LICENSE-APACHE">Apache License, Version
2.0</a> or <a href="LICENSE-MIT">MIT license</a> at your option.
</sup>

<br>

<sub>
Unless you explicitly state otherwise, any contribution intentionally submitted
for inclusion in this crate by you, as defined in the Apache-2.0 license, shall
be dual licensed as above, without any additional terms or conditions.
</sub>