#rest-client #proc-macro #rest #client #macro #serde

restcrab

Procedural macro to automatically generate a REST client from a trait definition

4 releases

0.2.0 Jul 14, 2022
0.1.2 Jan 25, 2022
0.1.1 Sep 16, 2021
0.1.0 Sep 13, 2021

#385 in HTTP client

MIT license

15KB
186 lines

Restcrab

crates.io docs.rs

Restcrab provides a procedural macro restcrab and a trait Restcrab for generating a REST client from a trait definition.

Usage

use std::collections::HashMap;

use serde::{Serialize, Deserialize};
use restcrab::{restcrab, Restcrab, crabs::reqwest};

#[derive(Serialize, Deserialize)]
struct Request {
  id: i32
}

#[derive(Serialize, Deserialize)]
struct Response {
  message: String
}

#[restcrab(crab = "reqwest::Reqwest")]
trait Service {
  #[restcrab(method = "GET", uri = "/empty")]
  fn uri_from_attribute();

  #[restcrab(method = "GET", uri = "/empty/{name}")]
  fn uri_from_attribute_with_parameter(#[parameter] name: &str);

  #[restcrab(method = "GET")]
  fn uri_from_method_name();

  #[restcrab(method = "GET", uri = "/static_header", header("Content-Type", "application/json"))]
  fn static_header();

  #[restcrab(method = "GET", uri = "/static_headers", header("Content-Type", "application/json"), header("User-Agen", "Restcrab"))]
  fn static_headers();

  #[restcrab(method = "GET", uri = "/static_query", query("some", "query"), query("another", "one"))]
  fn static_query();

  #[restcrab(method = "POST", uri = "/static_body", body = "0")]
  fn static_body() -> String;

  #[restcrab(method = "POST", uri = "/dynamic_headers")]
  fn dynamic_headers(#[headers] headers: HashMap<String, String>) -> String;

  #[restcrab(method = "POST", uri = "/dynamic_queries")]
  fn dynamic_queries(#[queries] queries: HashMap<String, String>) -> String;

  #[restcrab(method = "POST", uri = "/dynamic_headers", header("Content-Type", "application/json"))]
  fn both_headers(#[headers] headers: HashMap<String, String>) -> String;

  #[restcrab(method = "POST", uri = "/dynamic_body")]
  fn dynamic_body(#[body] body: Request) -> Response;
}

fn main() {
  let client = ServiceClient::from_options(reqwest::Options {
    base_url: "https://service.url".parse().unwrap()
  }).unwrap(); 

  let mut headers = HashMap::new();
  headers.insert("User-Agen".to_string(), "Restcrab".to_string());

  let uri_from_attribute:   ()        = client.uri_from_attribute().unwrap();
  let uri_from_method_name: ()        = client.uri_from_method_name().unwrap();
  let static_header:        ()        = client.static_header().unwrap();
  let static_headers:       ()        = client.static_headers().unwrap();
  let static_body:          String    = client.static_body().unwrap();
  let dynamic_headers:      String    = client.dynamic_headers(headers.clone()).unwrap();
  let both_headers:         String    = client.both_headers(headers).unwrap();
  let dynamic_body:         Response  = client.dynamic_body(Request { id: 0 }).unwrap();
}

Modular Backends (crabs)

Because I like to use unhelpful terminology a backend for restcrab is called a crab.

Types which implement the Restcrab trait can be used as crabs.

The crate provides one crab which uses the Reqwest http client.

If you want to implement your own crab please look at the provided implementation as starting off point

Dependencies

~4–17MB
~235K SLoC