Typescript typings

[HeyJ0e]

Is there a definition file for typescript typings?

[HeyJ0e]

I've created a version:

declare module 'node-discover' {
  import { EventEmitter } from 'events';
  import { RemoteInfo } from 'dgram';

  type Options = {
    helloInterval?: number;
		checkInterval?: number;
		nodeTimeout?: number;
		masterTimeout?: number;
    address?: string;
		port?: number;
		broadcast?: string;
		multicast?: string;
		multicastTTL?: number;
		unicast?: string | string[];
		key?: string;
		mastersRequired?: number;
		weight?: number;
		client?: boolean;
		server?: boolean;
		reuseAddr?: boolean;
		exclusive?: boolean;
		ignoreProcess?: boolean;
		ignoreInstance?: boolean;
		start?: boolean;
		hostname?: string;
  };

  type Message<T=unknown> = {
    event: string;
    pid: string;
    iid: string;
    hostName: string;
    data?: T;
  };

  type Node<A=unknown> = {
    isMaster: boolean;
    isMasterEligible: boolean;
    weight: number;
    address: string;
    lastSeen: number;
    hostName: string;
    port: number;
    id: string;
    advertisement?: A;
  };

  type ThisNode<A=unknown> = {
    isMaster: boolean;
    isMasterEligible: boolean;
    weight: number;
    address: string;
    advertisement?: A;
  };

  type ChannelListener<D> = (data: D, obj: Message<D>, rinfo: RemoteInfo) => void;

  class Discover<A=any, C extends Record<string, any>=Record<string, any>> extends EventEmitter {
    nodes: Record<string, Node>;
    constructor(callback?: (error: Error, something: boolean) => void);
    constructor(options?: Options, callback?: (error: Error, success: boolean) => void);

    promote(): void;
    demote(permanent: boolean): void;
    join<T extends keyof C>(channel: T, cb: ChannelListener<C[T]>): boolean;
    leave<T extends keyof C>(channel: T): boolean;
    advertise(advertisement: A): void;
    send<T extends keyof C>(channel: T, obj: C[T]): boolean;
    start(callback?: (error: Error, success: boolean) => void): false | boolean;
    stop(): false | boolean;
    eachNode(fn: (node: Node<A>) => void): void;

    on(event: 'promotion', listener: (me: ThisNode<A>) => void): this;
    on(event: 'demotion', listener: (me: ThisNode<A>) => void): this;
    on(event: 'added', listener: ChannelListener<Node<A>>): this;
    on(event: 'removed', listener: (node: Node<A>) => void): this;
    on(event: 'master', listener: ChannelListener<Node<A>>): this;
    on(event: 'helloReceived', listener: (node: Node<A>, obj: Message<Node<A>>, rinfo: RemoteInfo, isNew: boolean, wasMaster: null | boolean) => void): this;
    on(event: 'helloEmitted', listener: () => void): this;
    on(event: 'error', listener: (error: Error) => void): this;
    on(event: 'check', listener: () => void): this;
    on(event: 'started', listener: (self: Discover) => void): this;
    on(event: 'stopped', listener: (self: Discover) => void): this;
    on(channel: 'hello', listener: ChannelListener<A>): this;
    on<T extends keyof C>(channel: T, listener: ChannelListener<C[T]>): this;
  }
  
  export = Discover;
}

I've made it generic, so you can define the advertisement and channel data:

type Advertisement = {
  prop1: number;
  prop2: string;
};

type Channels = {
  channel1: number;
  channel2: string;
  channel3: {
    prop: boolean;
  };
};

const d = new Discover<Advertisement, Channels>();

[wankdanker]

I added your code as index.d.ts here. Would that accomplish what you need?

[HeyJ0e]

Mostly yes. I think it's worth mentioning in the readme with an example (like the one I provided).

Did you check the definitions? I'd be happy if someone could verify them.

[chapterjason]

Changed a bit:

• Add exports for the types
• Update Discover to default export
• Add me property
• Add broadcast with instance id (Another issue with easier access to this id would be awesome)

In long term I would recommend switching to typescript, it's a lot easier to maintain. If you need any help just ask.

declare module "node-discover" {
    import { EventEmitter } from "events";
    import { RemoteInfo } from "dgram";

    export type Options = {
        helloInterval?: number;
        checkInterval?: number;
        nodeTimeout?: number;
        masterTimeout?: number;
        address?: string;
        port?: number;
        broadcast?: string;
        multicast?: string;
        multicastTTL?: number;
        unicast?: string | string[];
        key?: string;
        mastersRequired?: number;
        weight?: number;
        client?: boolean;
        server?: boolean;
        reuseAddr?: boolean;
        exclusive?: boolean;
        ignoreProcess?: boolean;
        ignoreInstance?: boolean;
        start?: boolean;
        hostname?: string;
    };

    export type Message<T = unknown> = {
        event: string;
        pid: string;
        iid: string;
        hostName: string;
        data?: T;
    };

    export type Node<A = unknown> = {
        isMaster: boolean;
        isMasterEligible: boolean;
        weight: number;
        address: string;
        lastSeen: number;
        hostName: string;
        port: number;
        id: string;
        advertisement?: A;
    };

    export type ThisNode<A = unknown> = {
        isMaster: boolean;
        isMasterEligible: boolean;
        weight: number;
        address: string;
        advertisement?: A;
    };

    export type ChannelListener<D> = (data: D, obj: Message<D>, rinfo: RemoteInfo) => void;

    export type Network = {
        instanceUuid: string;
    };

    export default class Discover<A = any, C extends Record<string, any> = Record<string, any>> extends EventEmitter {
        nodes: Record<string, Node>;

        me: ThisNode<A>;

        broadcast: Network;

        constructor(callback?: (error: Error, something: boolean) => void);
        constructor(options?: Options, callback?: (error: Error, success: boolean) => void);

        promote(): void;

        demote(permanent: boolean): void;

        join<T extends keyof C>(channel: T, cb: ChannelListener<C[T]>): boolean;

        leave<T extends keyof C>(channel: T): boolean;

        advertise(advertisement: A): void;

        send<T extends keyof C>(channel: T, obj: C[T]): boolean;

        start(callback?: (error: Error, success: boolean) => void): false | boolean;

        stop(): false | boolean;

        eachNode(fn: (node: Node<A>) => void): void;

        on(event: "promotion", listener: (me: ThisNode<A>) => void): this;
        on(event: "demotion", listener: (me: ThisNode<A>) => void): this;
        on(event: "added", listener: ChannelListener<Node<A>>): this;
        on(event: "removed", listener: (node: Node<A>) => void): this;
        on(event: "master", listener: ChannelListener<Node<A>>): this;
        on(event: "helloReceived", listener: (node: Node<A>, obj: Message<Node<A>>, rinfo: RemoteInfo, isNew: boolean, wasMaster: null | boolean) => void): this;
        on(event: "helloEmitted", listener: () => void): this;
        on(event: "error", listener: (error: Error) => void): this;
        on(event: "check", listener: () => void): this;
        on(event: "started", listener: (self: Discover) => void): this;
        on(event: "stopped", listener: (self: Discover) => void): this;
        on(channel: "hello", listener: ChannelListener<A>): this;
        on<T extends keyof C>(channel: T, listener: ChannelListener<C[T]>): this;
    }
}

[wankdanker]

Thanks, @chapterjason. I've updated https://github.com/wankdanker/node-discover/tree/issue-44-index.d.ts, if it looks good to everyone, including whatever is necessary in package.json (or elsewhere) to tie it all together, lmk. I can merge it and release.

Cheers!

[chapterjason]

I think the most is covered, but if you can wait several days I will take a look and will improved it.

[HeyJ0e]

Making exports is a good idea, but I think exposing the me and the broadcast property is not that so. This would make the false impression that you can modify them. It would be better to have getters (as you mentioned) or at least mark as readonly.

Plus a minor thing: quotes. I don't know what's the policy for this project, in the code I saw both single and double,

[chapterjason]

Making exports is a good idea, but I think exposing the me and the broadcast property is not that so. This would make the false impression that you can modify them. It would be better to have getters (as you mentioned) or at least mark as readonly.

If you take a look in the source they are accessible even if there are types or not, that shouldn't be an issue for the types. This should be changed in source first. There are even more things that are accessible and not in the proposed types.

Plus a minor thing: quotes. I don't know what's the policy for this project, in the code I saw both single and double,

I don't know if there are any policies, I think it's another issue to introduce something like eslint.

[HeyJ0e]

Yes, there's more things accessible, but that's true for a lot of javascript projects. I think we shouldn't encourage this behaviour with the types but nudge users to the 'right direction'. Let's say like this:

readonly me: Readonly<ThisNode<A>>;

[chapterjason]

I totally agree to guide the user. But I would change this in the source first, cause this will only apply for typescript users. In all other cases (except docs) like:

a look in the source

node-discover/lib/discover.js

Lines 177 to 183 in 347dd57

	self.me = {
	isMaster : false,
	isMasterEligible: self.settings.server, //Only master eligible by default if we are a server
	weight : settings.weight,
	address : '127.0.0.1', //TODO: get the real local address?
	advertisement : options.advertisement
	};

console.log objects

const Discover = require("node-discover");

const d = new Discover({}, () => {
    console.log(d);
});

just override properties

const Discover = require("node-discover");

const d = new Discover({}, () => {
    d.broadcast.instanceUuid = 'bar';
    console.log(d.broadcast.instanceUuid);
});

$ node index.js
bar

a good IDE shows you the properties

It is possible to do this. So I would defer this and change the source first.

//EDIT
Even in the examples:

node-discover/examples/basic-argv.js

Line 20 in 347dd57

console.log('instanceUuid', d.broadcast.instanceUuid);

[chapterjason]

Hey @wankdanker and @HeyJ0e

several days ago I refactored the whole project.

Highlights:

• Full TypeScript support (Full (re)written in TypeScript)

  • Define advertisement and channel and message data format
    

    

  • Typed events
    

• Code documentation

  

• Documentation generation with typedoc

• Decoupled leadership election

• Decoupled different network types (unicast, multicast, broadcast)

• Latest supported version to node 10

I think several things could be improved, but in first place it's a good start.

The examples should be changed to typescript too.
It is also not good to have dev dependencies for "better" examples, it is just a bad DX.

Take a look in the fork under the branch project-refactor:
https://github.com/chapterjason/node-discover/tree/project-refactor

[wankdanker]

Hey @chapterjason. It looks pretty nice. Would you be willing to take over maintainership of the project if this gets merged? I don't have any time to help maintain a code base that I'm familiar with, let alone a complete rewrite in another language.