fix for variable name and add typescript typings

[retorquere]

this PR fixes a variable that accidentally was replaced by its type, adds typescript typings, and updates npm modules. The existing modules didn't pass npm audit, they currently do even if that generates warnings when you run the tests; the warnings relate to this and given that discussion it seems to me it's better to have the updates with warnings than the old modules.

[coveralls]

Pull Request Test Coverage Report for Build 25

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 100.0%

---

Totals
Change from base Build 21:	0.0%
Covered Lines:	54
Relevant Lines:	54

---

💛 - Coveralls

[cmseaton42]

First of all, thanks for the PR! Ive been wanting to go back and add typings for this module for some time now.

That said, should be make the types more specific (vs using any all around)?

[retorquere]

compare_func could be more specific, but for the others, the user can pass anything, no?

[cmseaton42]

What about something like this?

declare type Arguments<T> = [T] extends [(...args: infer U) => any] ? U : [T] extends [void] ? [] : [T];

declare type Task<T> = () => Promise<T>;

declare class TaskEasy<C> {
    constructor(compare_func: (a: C, b: C) => boolean, max_queue_size?: number);
    schedule<P, T extends Task<P>>(task: T, args: Arguments<T>, priority_obj: C): Promise<P>;
}

I got the Arguments type from another project.

This is totally untested by the way. Just threw something together. Thoughts?

[retorquere]

I am not that well versed in typescript :)

[cmseaton42]

no worries, I'll try and test it soon and see if it works out. If so, ill send you the updates for your PR and then pull I will pull it once all is well. Thanks again 😄

[cmseaton42]

I went ahead a got a version of what i had above working (see below)...

// Per Module-class.d.ts documentation
export = TaskEasy;

// Task Easy Class
declare class TaskEasy<C> {
    constructor(compare_func: (ob1: C, obj2: C) => boolean, max_queue_size?: number);
    schedule<P, T extends TaskEasy.Task<P>>(task: T, args: TaskEasy.Arguments<T>, priority_obj: C): Promise<P>;
}

declare namespace TaskEasy {
    // Extract argument types from passed function type
    export type Arguments<T> = [T] extends [(...args: infer U) => any] ? U : [T] extends [void] ? [] : [T];

    // Generic task type, must return promise
    export type Task<T> = (...args: any[]) => Promise<T>;
}

[cmseaton42]

The typescript usage of the example from the the README becomes as follows...

import TaskEasy from "task-easy";

// Define interface for priority
//  objects to be used in the
//  TaskEasy instance
interface IPriority {
    priority: number;
    timestamp: Date;
}

// Define delay function type
// -> Must extend  Task<T>: (...args) => Promise<T>
type delayFn = (ms: number) => Promise<undefined>;

// Define delay function of type 'delayFn' defined above
const delay: delayFn = ms => new Promise(resolve => setTimeout(resolve, ms));

// Define priority function
// -> Must extend (obj1: T, obj2: T) =>
const prioritize = (obj1: IPriority, obj2: IPriority) => {
    return obj1.priority === obj2.priority
        ? obj1.timestamp.getTime() < obj2.timestamp.getTime() // Return true if task 1 is older than task 2
        : obj1.priority > obj2.priority; // return true if task 1 is higher priority than task 2
};

// Initialize new queue
const queue = new TaskEasy(prioritize); // equivalent of TaskEasy<IPriority>(prioritize) via type inference

// .schedule accepts the task signature,
// an array or arguments, and a priority object
// -> with type inference
const task1 = queue
    .schedule(delay, [100], { priority: 1, timestamp: new Date() })
    .then(() => console.log("Task 1 ran..."));

const task2 = queue
    .schedule(delay, [100], { priority: 1, timestamp: new Date() })
    .then(() => console.log("Task 2 ran..."));

// Definitely typed
const task3 = queue
    .schedule<undefined, delayFn>(delay, [100], { priority: 2, timestamp: new Date() })
    .then(() => console.log("Task 3 ran..."));

const task4 = queue
    .schedule<undefined, delayFn>(delay, [100], { priority: 1, timestamp: new Date() })
    .then(() => console.log("Task 4 ran..."));

const task5 = queue
    .schedule<undefined, delayFn>(delay, [100], { priority: 3, timestamp: new Date() })
    .then(() => console.log("Task 5 ran..."));

// OUTPUT
// Task 1 ran...
// Task 5 ran...
// Task 3 ran...
// Task 2 ran...
// Task 4 ran...

[cmseaton42]

@retorquere You should be able to update to v0.2.1 to get the types. Let me know if you find any bugs 🐛. I tested locally and it seems to be working as intended.

[retorquere]

When I have

new TaskEasy((t1, t2) => t1.priority === t2.priority ? t1.timestamp.getTime() < t2.timestamp.getTime() : t1.priority > t2.priority)

I get

TS2339: Property 'priority' does not exist on type 'unknown'.

[retorquere]

Oh wait sorry, have to declare the prio type. Yep, that works!

[retorquere]

I do have to make the import

import TaskEasy = require("task-easy");

Otherwise I must enable esModuleInterop and that gave me problems in the past in my builds.

[cmseaton42]

Can you not import it with import TaskEasy from 'task-easy';??? This import worked for me when I was testing locally.

[retorquere]

If I do

import TaskEasy from 'task-easy'

I get

TS1259: Module '"node_modules/task-easy/src/index"' can only be default-imported using the 'esModuleInterop' flag

And turning on the esModuleInterop gave me a lot of trouble last time. The behavior for = require is described here; from what I gather the preferred format for exports is

module.exports = {
  TaskEasy
}

and then I can do import { TaskEasy } from 'task-easy'. import = require works too and it's supported in typescript, but IIRC treeshaking won't work.

[cmseaton42]

I see... I will update the module to export in the way that you have alluded to.

module.exports = {
  TaskEasy
}

Since this is technically a breaking change, I will release a new major revision v1.0.0

[retorquere]

Hold on, let me run my tests on that

[retorquere]

The declaration file now looks like

// Per Module-class.d.ts documentation
  
// Task Easy Class
export class TaskEasy<C> {
    constructor(compare_func: (ob1: C, obj2: C) => boolean, max_queue_size?: number);
    schedule<P, T extends TaskEasy.Task<P>>(task: T, args: TaskEasy.Arguments<T>, priority_obj: C): Promise<P>;
}

declare namespace TaskEasy {
    // Extract argument types from passed function type
    export type Arguments<T> = [T] extends [(...args: infer U) => any] ? U : [T] extends [void] ? [] : [T];

    // Generic task type, must return promise
    export type Task<T> = (...args: any[]) => Promise<T>;
}

for me and indeed the module.exports as above.

[cmseaton42]

The module should be updated now 🎉

Let me know if all is well :)

[retorquere]

All is well!