# serde_assert
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Testing library for [`serde`](https://crates.io/crates/serde) [`Serialize`](https://docs.rs/serde/latest/serde/trait.Serialize.html) and [`Deserialize`](https://docs.rs/serde/latest/serde/trait.Deserialize.html) implementations.
This library provides a [`Serializer`](https://docs.rs/serde_assert/latest/serde_assert/struct.Serializer.html) and [`Deserializer`](https://docs.rs/serde_assert/latest/serde_assert/struct.Deserializer.html) to be used in writing unit tests to assert the behavior of manual [`Serialize`](https://docs.rs/serde/latest/serde/trait.Serialize.html) and [`Deserialize`](https://docs.rs/serde/latest/serde/trait.Deserialize.html) implementations, respectively. The implementation behavior can be verified using a sequence of [`Token`](https://docs.rs/serde_assert/latest/serde_assert/struct.Token.html)s representing a generic serialized state.
## Usage
The examples below use the [`claims`](https://crates.io/crates/claims) crate for convenient assertions.
### Testing Serialization
The [`Serializer`](https://docs.rs/serde_assert/latest/serde_assert/struct.Serializer.html) returns a sequence of [`Token`](https://docs.rs/serde_assert/latest/serde_assert/struct.Token.html)s representing the serialization of a value. The returned `Token`s can be checked to be equal to an expected value.
```rust
use claims::assert_ok_eq;
use serde::Serialize;
use serde_assert::{
Serializer,
Token,
};
let serializer = Serializer::builder().build();
assert_ok_eq!(true.serialize(&serializer), [Token::Bool(true)]);
```
### Testing Deserialization
A [`Deserializer`](https://docs.rs/serde_assert/latest/serde_assert/struct.Deserializer.html) is constructed by providing a sequence of [`Token`](https://docs.rs/serde_assert/latest/serde_assert/struct.Token.html)s to be deserialized into a value.
```rust
use claims::assert_ok_eq;
use serde::Deserialize;
use serde_assert::{
Deserializer,
Token,
};
let mut deserializer = Deserializer::builder([Token::Bool(true)]).build();
assert_ok_eq!(bool::deserialize(&mut deserializer), true);
```
## Comparison with [`serde_test`](https://crates.io/crates/serde_test)
This crate provides more flexibility than `serde_test` at the expense of more verbosity. While `serde_test` provides a small API of simple assertion functions, this crate will require you to call [`serialize()`](https://docs.rs/serde/latest/serde/trait.Serialize.html#tymethod.serialize) and [`deserialize()`](https://docs.rs/serde/latest/serde/trait.Deserialize.html#tymethod.deserialize) and assert yourself that the results are as expected.
While some users may find that the smaller API of `serde_test` is sufficient for their use-case, others will find that the flexibility of this crate makes testing more complicated `Serailize` and `Deserialize` implementations easier. Among other things, this crate's API provides these advantages:
- Direct access to the [`Serializer`](https://docs.rs/serde_assert/latest/serde_assert/struct.Serializer.html) and [`Deserializer`](https://docs.rs/serde_assert/latest/serde_assert/struct.Deserializer.html), allowing use of all parts of the `serde` `Serializer` and `Deserializer` APIs, such as deserializing types that implement [`DeserializeSeed`](https://docs.rs/serde/latest/serde/de/trait.DeserializeSeed.html).
- Customization of [`Serializer`](https://docs.rs/serde_assert/latest/serde_assert/struct.Serializer.html)s and [`Deserializer`](https://docs.rs/serde_assert/latest/serde_assert/struct.Deserializer.html)s, allowing configuration of things like human-readability, whether the `Deserializer` should interpret sequences of [`Token`](https://docs.rs/serde_assert/latest/serde_assert/struct.Token.html)s as self-describing, and zero-copy deserialization.
- Sophisticated comparison of serialized [`Token`](https://docs.rs/serde_assert/latest/serde_assert/struct.Token.html) sequences, including allowing testing of types whose serialized form can include items in arbitrary order, such as when serializing a [`HashSet`](https://docs.rs/hashbrown/latest/hashbrown/struct.HashSet.html).
## Minimum Supported Rust Version
This crate is guaranteed to compile on stable `rustc 1.56.0` and up.
## License
This project is licensed under either of
* Apache License, Version 2.0
([LICENSE-APACHE](https://github.com/Anders429/serde_assert/blob/HEAD/LICENSE-APACHE) or
http://www.apache.org/licenses/LICENSE-2.0)
* MIT license
([LICENSE-MIT](https://github.com/Anders429/serde_assert/blob/HEAD/LICENSE-MIT) or
http://opensource.org/licenses/MIT)
at your option.
### Contribution
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.