https://github.com/freyskeyd/chekov
A CQRS/ES framework for building application in Rust
https://github.com/freyskeyd/chekov
cqrs cqrs-es eventsourcing rust
Last synced: 6 months ago
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A CQRS/ES framework for building application in Rust
- Host: GitHub
- URL: https://github.com/freyskeyd/chekov
- Owner: Freyskeyd
- Created: 2020-05-27T18:05:23.000Z (over 5 years ago)
- Default Branch: master
- Last Pushed: 2024-04-30T13:26:21.000Z (over 1 year ago)
- Last Synced: 2025-03-25T19:12:11.725Z (7 months ago)
- Topics: cqrs, cqrs-es, eventsourcing, rust
- Language: Rust
- Homepage:
- Size: 7.22 MB
- Stars: 26
- Watchers: 2
- Forks: 0
- Open Issues: 6
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
Awesome Lists containing this project
README
Chekov
A CQRS/ES framework for building application in Rust
[](https://github.com/Freyskeyd/chekov/actions) [](https://coveralls.io/github/Freyskeyd/chekov?branch=master) [](https://deps.rs/repo/github/freyskeyd/chekov) [](https://crates.io/crates/chekov) [](https://docs.rs/chekov) [](https://freyskeyd.github.io/chekov/chekov/)
## Table of Contents
- [Features](#features)
- [Getting started](#getting-started)
- [FAQ](#faq)
- [Need help?](#need-help)
- [Contributing](#contributing)
---
## Features
- `Postgres` EventStore backend
- Dispatch `Command` to `Aggregate` or `CommandHandler`
- Generate `Event` from `Aggregate` and persist them
- Apply `Event` to `Aggregate`
- Store and notify `Event` with subscriptions
- Dispatch `Event` to `EventHandler`
## Getting started
### Choosing an EventStore backend
Chekov works only with `Postgres` backend for now (and `InMemory` for test purpose). The choice is easy to make!
But some more backends need to be implemented, [see the related issue](#14).
### Defining Aggregates
An Aggregate is a struct that hold a domain state. Here's an example of a UserAggregate:
```rust
#[derive(Default, Aggregate)]
#[aggregate(identity = "user")]
struct User {
user_id: Option,
account_id: Option,
}
/// Define an Executor for the `CreateUser` command
/// The result is a list of events in case of success
impl CommandExecutor for User {
fn execute(cmd: CreateUser, _state: &Self) -> Result, CommandExecutorError> {
Ok(vec![UserCreated {
user_id: cmd.user_id,
account_id: cmd.account_id,
}])
}
}
/// Define an Applier for the `UserCreated` event
/// Applier is a mutation action on the aggregate
#[chekov::applier]
impl EventApplier for User {
fn apply(&mut self, event: &UserCreated) -> Result<(), ApplyError> {
self.user_id = Some(event.user_id);
self.account_id = Some(event.account_id);
Ok(())
}
}
```
### Defining Commands
You need to create a struct per command, any type of struct can implement `Command` but we advise to use struct for a better readability.
A command can only produce (or not) one type of events and it targets a single Aggregate.
A command must have a single and unique `identifier` that is used to route the command to the right target.
```rust
#[derive(Debug, Command)]
#[command(event = "UserCreated", aggregate = "User")]
struct CreateUser {
#[command(identifier)]
user_id: Uuid,
account_id: Uuid,
}
```
### Defining Events
An `Event` can be a `struct` or an `enum`.
```rust
#[derive(Event, Deserialize, Serialize)]
struct UserCreated {
user_id: Uuid,
account_id: Uuid,
}
```
### Defining Saga
Not implemented yet
## FAQ
### Does `Chekov` is production ready ?
No its not. Some critical part of the project are still not implemented and a lot of code needs to be refactored before that.
## Need Help?
Feel free to open issue in case of bugs or features requests. [Discussions](https://github.com/Freyskeyd/chekov/discussions) are also a great starts if you have issue that are not bugs nor features requests.
## Contributing
The project is really early staged and have a lot of pending tasks, one major tasks is to produce a roadmap or some issues that can be used to expose the project vision. Feel free to open a [Discussions](https://github.com/Freyskeyd/chekov/discussions) around it if you want !