AsyncStatus JS

Manages the status of an async process.

• Built-in TypeScript declarations.
• Built-in Javascript / TypeScript map declarations.
• Comprehensive unit testing.
• Available at npmjs.com
• Source Code

Table Of Content

• Installation
  • As project dependency
  • As script dependency
• Basic usage snippets
  • async / await
  • Observable
• Status management / Class interface
  • Use
  • Check attempt stats
  • Check current state
  • Check last outcome state
  • Measure the time
• Final notes
• Examples

Installation

As project dependency

npm i @bugtamer/async-status

Available at npmjs.com

As script dependency

'require' demo example

1const bugtamer = require("@bugtamer/async-status")
2const dataAsyncStatus = new bugtamer.AsyncStatus();

or

1const bugtamer = require("@bugtamer/async-status/lib/async-status")
2const dataAsyncStatus = new bugtamer.AsyncStatus();

'import' demo example

1import { AsyncStatus } from '@bugtamer/async-status/lib/async-status';
2const dataAsyncStatus = new AsyncStatus();

Basic usage snippets

async / await

1dataAsyncStatus.start();
2try {
3    data = await fetchData();
4    dataAsyncStatus.end();
5} catch (error) {
6    dataAsyncStatus.abort();
7}

Observable

1dataAsyncStatus.start();
2const subscription = fetchData().subscribe(
3    response => {
4        data = response;
5        dataAsyncStatus.end();
6    },
7    error => {
8        dataAsyncStatus.abort();
9    }
10);

Status management / Class interface

Use

Current State	Method called / Sentence	Outcome
	new AsyncStatus()	idle state
idle	start()	ongoing state
ongoing	end()	idle state
ongoing	abort()	idle state
ongoing	start()	Throw an error
idle	end()	Throw an error
idle	abort()	Throw an error

Do not try to manage these errors, just fix your code. They point out that some method should never have called.

Check attempt stats

Sentence	Description
dataAsyncStatus.attempts	returns the number of calls to start()
dataAsyncStatus.successfulAttempts	returns the number of calls to end()
dataAsyncStatus.failedAttempts	returns the number of calls to abort()
dataAsyncStatus.resetAttemptStats()	all previous counters are set to 0

Check current state

In this section we understand by call a call to any of the following methods: start(), end() or abort().

Idle State

There is no process activity.

dataAsyncStatus.isIdle	Returns
When start() was never executed or the last call was end() or abort()	true
In any other case	false

Ongoing state

There is a process in progress.

dataAsyncStatus.isOngoing	Returns
When the last call was start() and therefore neither end() nor abort() have been called yet	true
In any other case	false

Check last outcome state

In this section we understand by call a call to any of the following methods: start(), end() or abort().

A successful outcome

dataAsyncStatus.wasSuccessful	Returns
When end() was the last method called	true
In any other case	false

A failed outcome

dataAsyncStatus.wasFailed	Returns
When abort() was the last method called	true
In any other case	false

Measure the time

In milliseconds (ms):

dataAsyncStatus.elapsedTime	Returns
when start() was never called	AsyncStatus.UNDEFINED_TIME (-1)
when start() was called but end() or abort() has not yet been called	Time elapsed since the call to start() to current time
when start() was called and eventually end() or abort() was also called	Elapsed time from call to start() to end() or abort() call

Final notes

• Using a single instance of AsyncStatus to control multiple independent asynchronous processes that overlap in time could lead to erratic behavior in your program.

• start() throws an error when is called more than Number.MAX_SAFE_INTEGER times (although is nearly unreachable).

Examples

• Angular demo example
• Check out the following example at RunKit:

1// const bugtamer = require("@bugtamer/async-status/lib/async-status")
2const bugtamer = require("@bugtamer/async-status")
3
4
5function showStats(asyncStatus, message) {
6    console.log(message)
7    console.log(`  - Attempts:     ${asyncStatus.attempts}`)
8    console.log(`    - successful: ${asyncStatus.successfulAttempts}`)
9    console.log(`    - failed:     ${asyncStatus.failedAttempts}`)
10    console.log(`  - State:`)
11    console.log(`    - idle:       ${asyncStatus.isIdle}`)
12    console.log(`    - ongoing:    ${asyncStatus.isOngoing}`)
13    console.log(`  - Outcome:`)
14    console.log(`    - successful: ${asyncStatus.wasSuccessful}`)
15    console.log(`    - failed:     ${asyncStatus.wasFailed}`)
16    console.log(`  - Time elapsed: ${asyncStatus.elapsedTime} ms`)
17}
18
19
20// Let's show where the Internation Space Station currently is.
21console.log("Let's see where the ISS is with Node " + process.version);
22
23// We can use any package from NPM since they are all built in.
24var getJSON = require("async-get-json"); 
25
26
27const status = new bugtamer.AsyncStatus();
28showStats(status, 'new AsyncStatus()')
29
30status.start()
31showStats(status, 'start()')
32
33
34const url = "http://api.open-notify.org/iss-now.json"; // change it to make it fail
35try {
36    // And we can use ES7 async/await to pull the ISS's position from the open API.
37    var result = await getJSON(url);
38
39    status.end()
40    showStats(status, 'end()')
41} catch (error) {
42    status.abort()
43    showStats(status, 'abort()')
44}
45
46
47if (!!result) {
48    // RunKit will automatically display the last statement and try to find its best representation:
49    result.iss_position;
50}

Example output

1Let's see where the ISS is with Node v14.20.1
2new AsyncStatus()
3  - Attempts:     0
4    - successful: 0
5    - failed:     0
6  - State:
7    - idle:       true
8    - ongoing:    false
9  - Outcome:
10    - successful: false
11    - failed:     false
12  - Time elapsed: -1 ms
13start()
14  - Attempts:     1
15    - successful: 0
16    - failed:     0
17  - State:
18    - idle:       false
19    - ongoing:    true
20  - Outcome:
21    - successful: false
22    - failed:     false
23  - Time elapsed: 1 ms
24end()
25  - Attempts:     1
26    - successful: 1
27    - failed:     0
28  - State:
29    - idle:       true
30    - ongoing:    false
31  - Outcome:
32    - successful: true
33    - failed:     false
34  - Time elapsed: 75 ms