rpclibrary/demo.ts

import { RPCServer, RPCSocket } from './Index'
import { RPCExporter } from './src/Interfaces'
import { RPCInterface } from './src/Types'

// TL;DR
const echo = (text: string) => text
const add = (a: number, b: number) : number => a + b
const getAsync = async () : Promise<{topic: string, message:string}>=> await new Promise((res, _) => {
    setTimeout(() => {
        res({
            topic: "Hey!!",
            message: "Hello World Async!"
        })
    }, 250)
})
const getCallback = (callback: Function) : string => {
    setTimeout(() => {
        try{
            callback({
                topic: "Hey!!",
                message: "Hello World Callback!"
            })
        }catch(e){
            console.log(String(e))
        }
    }, 250)
    return "Please wait for a callback :)"
}
new RPCServer(20000, [{
    name: 'MyRPCGroup1',
    exportRPCs: () => [
        echo,
        add,
        getAsync,
        {
            name: 'getCallback',
            hook: getCallback,
            onClose: (response, rpc) => { /* ... */ },
            onCallback: (...callbackArgs) => { /* ... */ }
        }
    ]
}])

new RPCSocket(20000, 'localhost').connect().then(async sock => {
    try{
        const RPCs = sock['MyRPCGroup1']
        await RPCs.echo("hello!").then(console.log)
        await RPCs.add(1, Math.PI).then(console.log)
        await RPCs.getAsync().then(console.log)
        await RPCs.getCallback(console.log).then(console.log)
    }catch(e){
        console.log(String(e))
    }
})

//Hooks and events
new RPCServer(20001, [{
    name: 'MyRPCGroup1',
    exportRPCs: () => [
        echo,
        add,
        getAsync,
        {
            name: 'getCallback',
            hook: getCallback,
            onClose: (response, rpc) => { /* client disconnected */ },
            onCallback: (...callbackArgs) => { /* callback triggered */ }
        }
    ],
}], {
    visibility: '127.0.0.1', //0.0.0.0
    closeHandler: (socket) => { /* global close handler */ },
    connectionHandler: (socket) => { /* new connection made */ },
    errorHandler: (socket, error, rpcname, argArr) => { /* An error occured inside a RPC */ },
})

const sock = new RPCSocket(20001, 'localhost')
sock.on('error', (e) => { /* handle error */ })
sock.on('close', () => { /* handle close event */ })

sock.hook('RPCName', (/* arg0, arg1, ..., argN */) => { /* bind client-side RPCs */ }) 
//Retrieve the socket from connectionHandler (Server-side) and trigger with 
//socket.call('RPCName', arg0, arg1, ..., argN)

sock.connect().then(_ => { /* ... */})

//Restricting access
new RPCServer(20002, [{
    name: 'MyRPCGroup1',
    exportRPCs: () => [
        echo,
        add,
        getAsync,
        {
            name: 'getCallback',
            hook: getCallback,
        }
    ],
}], {
    sesame: "sesame open",
    /* 
    OR check sesame dynamically
    and refine permissioning with accessfilter (optional)
    */

    //sesame: (sesame) => true
    //accessFilter: (sesame, exporter) => { return exporter.name === "MyRPCGroup1" && sesame === "sesame open" },
})

new RPCSocket(20002, 'localhost').connect("sesame open").then(async sock => {
    try{
        const RPCs = sock['MyRPCGroup1']
        await RPCs.echo("hello!").then(console.log)
        await RPCs.add(1, Math.PI).then(console.log)
        await RPCs.getAsync().then(console.log)
        await RPCs.getCallback(console.log).then(console.log)
    }catch(e){
        console.log(String(e))
    }
})


//TypeScript and pseudo-interfaces

type MyInterface = {
    MyRPCGroup1: {
        echo: (x: string) => string
        add: (a: number, b: number) => number
        getAsync: () => Promise<{ topic: string, message: string }>
        getCallback: (callback:Function) => string
    }
};


/*
exportRPCs is now type safe. Try swapping echo for badEcho.
Sadly TSC's stack traces aren't the best, but try to scroll to the bottom of them to find useful info like

Type '(x: boolean) => number' is not assignable to type '(x: string) => string'
*/

const badEcho = (x: boolean) : number => 3

new RPCServer<MyInterface>(20003, [{
    name: 'MyRPCGroup1',
    exportRPCs: () => [
        //badEcho,
        echo,
        add,
        getAsync,
        {
            name: 'getCallback',
            hook: getCallback,
        }
    ],
}])

new RPCSocket<MyInterface>(20003, 'localhost').connect().then(async sock => {
    try{
        await sock.MyRPCGroup1.echo("hello!").then(console.log)
        await sock.MyRPCGroup1.add(1, Math.PI).then(console.log)
        await sock.MyRPCGroup1.getAsync().then(console.log)
        await sock.MyRPCGroup1.getCallback(console.log).then(console.log)
    }catch(e){
        console.log(String(e))
    }
})


//Class-based pattern

interface IMyImplementation {
    echo: (x: string) => string
    add: (a: number, b: number) => number
    getAsync: () => Promise<{ topic: string, message: string }>
    getCallback: (callback:Function) => string
}

type IfcGenerator<Name extends string, Interface, keys extends keyof Interface = keyof Interface> = {
    [name in Name]: {
        [key in keys] : Interface[key]
    }
}

type MyIfc = IfcGenerator<"MyRPCGroup1", IMyImplementation>

class MyImplementation implements IMyImplementation, RPCExporter<MyIfc>{
    //"X" as "X" syntax is required to satisfy the type system (as it assumes string)
    name = "MyRpcGroup11" as "MyRPCGroup1"

    //List the functions you declared in MyIfc
    exportRPCs = () => [
        this.echo,
        this.add,
        this.getAsync,
        this.getCallback
    ]

    //Write your implementations as you normally would
    echo = (text: string) => text

    add = (a: number, b: number) : number => a + b

    getAsync = async () : Promise<{topic: string, message:string}>=> await new Promise((res, _) => {
        setTimeout(() => {
            res({
                topic: "Hey!!",
                message: "Hello World Async!"
            })
        }, 250)
    })

    getCallback = (callback: Function) : string => {
        setTimeout(() => {
            try{
                callback({
                    topic: "Hey!!",
                    message: "Hello World Callback!"
                })
            }catch(e){
                console.log(String(e))
            }
        }, 250)
        return "Please wait for a callback :)"
    }
}

new RPCServer<MyIfc>(20004, [new MyImplementation(), /* ... other RPCExporters */])

new RPCSocket<MyIfc>(20004, 'localhost').connect().then(async sock => {
    try{
        await sock.MyRPCGroup1.echo("hello!").then(console.log)
        await sock.MyRPCGroup1.add(1, Math.PI).then(console.log)
        await sock.MyRPCGroup1.getAsync().then(console.log)
        await sock.MyRPCGroup1.getCallback(console.log).then(console.log)
    }catch(e){
        console.log(String(e))
    }
})