Cronus

Cronus aims to help you focusing on business logic code only instead of the other glue code.

Online playground is here. Documentation is here.

Usage

$ cargo install cronus_cli

And it can be used like:

$ cronus_cli <your api file>

And it can be further integrated into the building process:

// build.rs
fn main() {
  let dir: String = env::var("CARGO_MANIFEST_DIR").unwrap();

  // Suppose your api file named "main.api" is located at 
  // same directory with the Cargo.toml.
  // 
  // If your api file does not have the name "main.api", 
  // the path should point to the that file instead of 
  // a simple directory.  
  std::process::Command::new("cronus_cli")
      .arg(&dir)
      .output()
      .expect("failed to generate API");
}

Introduction

Cronus contains a list of code generators, which insipred by the Clean Architecture, for Rust, Typescript, OpenAPI, and more.

According to one or more configuration files( can be either in YAML (.yml or .yaml) or our DSL(.api) ), Cronus can generate nice and clean business logic related code and glue code for a bunch of different controller layers(HTTP, GraphQL, etc.) powered by different libraries or frameworks.

Cronus

# More fine-grained configuration can be found at documentation

# For 'rust' generator
global [generator.rust.file = "src/generated.rs"]
global [generator.rust.async]
global [generator.rust.async_trait]

# For 'rust_axum' generator
global [generator.rust_axum.file = "src/generated.rs"]


struct Todo {
  id: string
  content: string
}

usecase Todo {
  createTodo {
      in {
          content: string
      }

      out {
          todo: Todo
      }
  }
}

Cronus can be used to generate the following Business Logic interface code:

Generated Rust

use serde::{Deserialize, Serialize};
use async_trait::async_trait;

#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
pub struct Todo {
  pub id: String,
  pub content: String,
}

#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
pub struct CreateTodoRequest {
  pub content: String,
}

#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
pub struct CreateTodoResponse {
  pub todo: Todo,
}

#[async_trait]
pub trait TodoUsecase {
  async  fn create_todo(&self, request: CreateTodoRequest) -> Result<CreateTodoResponse, Box<dyn std::error::Error>>;
}

Cronus can even step further to generate the following Controller glue code:

Generated Rust (Axum)

use axum::{
    extract::State,
    http::{header, Response, StatusCode},
    response::IntoResponse,
    Extension, Json,
    Router
};

pub async fn create_todo(State(state): State<std::sync::Arc<Usecases>>, Json(request): Json<CreateTodoRequest>) -> Result<impl IntoResponse, (StatusCode, Json<serde_json::Value>)> {

  match state.todo.create_todo(request).await {
      Ok(res) => {
          Ok(Json(res))
      },
      Err(err) => {
          let mut err_obj = serde_json::Map::new();
          err_obj.insert("message".to_owned(), serde_json::Value::from(err.to_string()));
          Err((StatusCode::BAD_REQUEST, Json(serde_json::Value::Object(err_obj))))
      },
  }
}

#[derive(Clone)]
pub struct Usecases {
  pub todo: std::sync::Arc<dyn TodoUsecase + Send + Sync>,
}

pub fn router_init(usecases: std::sync::Arc<Usecases>) -> Router {
  Router::new()
    .route("", axum::routing::post(create_todo))
    .with_state(usecases)
}

Usecase Layer Generators

• Rust
• Typescript
• Python

Transportation Layer Generator

• Axum (HTTP, Rust)
• FastAPI (HTTP, Python)
• Tauri (work in progress)

Schema Generator

• OpenAPI v3
• Protobuf

Dev

Common

# Install the cli binary to the default folder so that you can call it
# everywhere as long as the folder is included in environment variable.
$ cargo install --path bin/cli
# Run the generators by the given API spec
$ cargo run -- examples/todo-rs/main.api
$ cargo run -- examples/todo-py/main.api

Docs

Dev

$ pip install mkdocs-material
$ mkdocs serve -f mkdocs.yaml

Publish

$ mkdocs gh-deploy