JSON RPC 2.0 Client

A collection of classes for creating JSON RPC 2.0 clients.

Install

``shell
npm i jsonrpc2-tsclient
`


Example

Example of the client decorator implementing RPC methods from reading
method signatures.

`ts
import {rpcClient, RPCHTTPClient} from "jsonrpc2-tsclient";

const transport = new RPCHTTPClient("http://localhost:8000/api/v1");

interface Vector3 {
x: number;
y: number;
z: number;
}

@rpcClient(transport, "math.")
class MathClient {
// @ts-ignore
async add(a: number, b: number): Promise {}
// @ts-ignore
async get_distance(a: Vector3, b: Vector3): Promise {}
}

const client = new MathClient();
client.add(2, 2).then(res => console.log(res));
client.get_distance({x: 1, y: 1, z: 1}, {x: 1, y: 1, z: 1}).then(res => console.log(res));
`

Usage

The JSONRPCClient will handle forming requests and parsing responses.
To call a JSON-RPC 2.0 method with an implementation of JSONRPCClient,
call the call method, passing it the name of the method to call and
the params.

If the response is JSON-RPC 2.0 result object, only the result will be
returned, none of the wrapper.

If the response is JSON-RPC 2.0 error response, and exception will be
thrown for the error.

A default HTTP and WebSocket client are provided.

`typescript
import {RPCHTTPClient} from "jsonrpc2-tsclient";
import {RPCWebSocketClient} from "jsonrpc2-tsclient";

let httpClient = new RPCHTTPClient("http://localhost:8000/api/v1");
client.call("divide", [0, 0])
.then(res => console.log(JSON-RPC Result: ${res}))
.catch(err => console.log(JSON-RPC Error: ${err}));

let wsClient = new RPCWebSocketClient("ws://localhost:8000/api/v1");
client.call("divide", [0, 0])
.then(res => console.log(JSON-RPC Result: ${res}))
.catch(err => console.log(JSON-RPC Error: ${err}));
wsClient.close();
`

JSONRPCClient Abstract Class

JSON-RPC 2.0 is transport agnostic. This library provides an abstract
class that can be extended to create clients for different transports.

Implementations

To make client for a transport, extend the JSONRPCClient class and
implement the sendAndGetJSON which takes a request object and is
expected to return a JSON-RPC 2.0 response as an object. JSONRPCClient
has a call method that uses this internally.

Example HTTP implementation:

`typescript
export class RPCHTTPClient extends JSONRPCClient {
url: string;
headers: object;

constructor(url: string, headers: object | null = null) {
super();
this.url = url;
this.headers = headers || {};
this.headers["Content-Type"] = "application/json";
}

protected async sendAndGetJSON(request: RequestObject): Promise {
return (await axios.post(this.url, request, {headers: this.headers})).data;
}
}
``