enum2contract 0.1.4

enum2contract is a no_std compatible rust derive macro that lets users specify contracts for pub/sub style messaging using strongly typed rust enums. Conversion methods for JSON and binary are created for the generated payloads.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102

# enum2contract

[<img alt="github" src="https://img.shields.io/badge/github-matthewjberger/enum2contract-8da0cb?style=for-the-badge&labelColor=555555&logo=github" height="20">](https://github.com/matthewjberger/enum2contract)
[<img alt="crates.io" src="https://img.shields.io/crates/v/enum2contract.svg?style=for-the-badge&color=fc8d62&logo=rust" height="20">](https://crates.io/crates/enum2contract)
[<img alt="docs.rs" src="https://img.shields.io/badge/docs.rs-enum2contract-66c2a5?style=for-the-badge&labelColor=555555&logo=docs.rs" height="20">](https://docs.rs/enum2contract)


enum2contract is a no_std compatible rust derive macro that lets users specify contracts for pub/sub style messaging using strongly typed rust enums.

## Usage

Add this to your `Cargo.toml`:

```toml
enum2contract = "0.1.4"
```

Example:

```rust
use enum2contract::EnumContract;
use serde::{Deserialize, Serialize};

#[derive(EnumContract)]
pub enum Message {
    #[topic("notify/{group}")]
    Notify,

    #[topic("notify_all")]
    NotifyAll,

    #[topic("system/{id}/start/{mode}")]
    Start { immediate: bool },
}

#[test]
fn notify_message() {
    let (topic, payload) = Message::notify("partial");
    assert_eq!(topic, "notify/partial");
    assert_eq!(payload, NotifyPayload::default());
}

#[test]
fn notify_all_message() {
    let (topic, payload) = Message::notify_all();
    assert_eq!(topic, "notify_all");
    assert_eq!(payload, NotifyAllPayload::default());
}

#[test]
fn start_message() {
    let (topic, payload) = Message::start("76", "idle");
    assert_eq!(topic, "system/76/start/idle");
    assert_eq!(payload, StartPayload { immediate: false });
}

#[test]
fn notify_payload_json_conversion() {
    let payload = NotifyPayload;
    let json = payload.to_json().unwrap();
    assert_eq!(json, "null");

    let payload2: NotifyPayload = NotifyPayload::from_json(&json).unwrap();
    assert_eq!(payload2, payload);
}

#[test]
fn notify_all_payload_json_conversion() {
    let payload = NotifyAllPayload;
    let json = payload.to_json().unwrap();
    assert_eq!(json, "null");

    let payload2: NotifyAllPayload = NotifyAllPayload::from_json(&json).unwrap();
    assert_eq!(payload2, payload);
}

#[test]
fn start_payload_json_conversion() {
    let payload = StartPayload { immediate: true };
    let json = payload.to_json().unwrap();
    assert_eq!(json, r#"{"immediate":true}"#);

    let payload2: StartPayload = StartPayload::from_json(&json).unwrap();
    assert_eq!(payload2, payload);
}

#[test]
fn notify_payload_from_json() {
    let json = "null";
    let payload = NotifyPayload::from_json(json).unwrap();
    assert_eq!(payload, NotifyPayload::default());
}

#[test]
fn notify_payload_from_json_with_data() {
    let json = r#"{"immediate": true}"#;
    let payload = StartPayload::from_json(json).unwrap();
    assert_eq!(payload, StartPayload { immediate: true });
}
```

> This crate is `#![no_std]` compatible but requires `alloc`.