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https://github.com/mkg0/promise-effects
Promise effects like retry, timeout, observation over promises for advanced use cases or test purposes.
https://github.com/mkg0/promise-effects
async cancelablepromise observe-promise polling promise promise-retry retry timeout wait
Last synced: 13 days ago
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Promise effects like retry, timeout, observation over promises for advanced use cases or test purposes.
- Host: GitHub
- URL: https://github.com/mkg0/promise-effects
- Owner: mkg0
- Created: 2018-06-30T10:42:47.000Z (over 6 years ago)
- Default Branch: master
- Last Pushed: 2023-01-06T04:23:08.000Z (almost 2 years ago)
- Last Synced: 2023-12-25T16:30:26.449Z (about 1 year ago)
- Topics: async, cancelablepromise, observe-promise, polling, promise, promise-retry, retry, timeout, wait
- Language: TypeScript
- Homepage:
- Size: 1.14 MB
- Stars: 3
- Watchers: 2
- Forks: 0
- Open Issues: 10
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
Awesome Lists containing this project
README
Promise Effects
=================================
[](https://www.npmjs.com/package/promise-effects)
[]()
Fully typed promise effects to play with async handlers in a pleasent way.
| Effect | Desc |
|-----------------------------------|-------------------------------------------------------|
| [retryPromise](#retryPromise) | Converts a promise creator to repetitive |
| [wait](#wait) | Creates a promise to resolve for the given time long. |
| [observePromise](#observePromise) | Creates observable promises from the given promise |
| [timeout](#timeout) | Timeout example |
| Polling | ⏱ Polling example |
| Latest | ⏱ |
| CancelablePromise | ⏱ |
## Usage
Install package
```sh
npm install promise-effects
```
Import module
```js
import { retryPromise } from 'promise-effects'
// or
import retryPromise from 'promise-effects/retryPromise'
```
## Effects
### **RetryPromise**
It's a high-order function that gives the capabilify of retry to a function that creates promise.
```js
const repetitiveFetch = retryPromise(fetch, {
retry: 3,
onReconnecting: ({ attemptNumber }) => console.log(`Fetching has failed(${attemptNumber})... Retrying...`),
})
repetitiveFetch('https://www.mocky.io/v2/5185415ba171ea3a00704eed')
.then(resp=> resp.json())
.then(console.log)
.catch(() => console.log('Failed!'))
// > Fetching has failed(1)... Retrying...
// > Fetching has failed(2)... Retrying...
// > Fetching has failed(3)... Retrying...
// > Failed!
```
#### Options
| Option Name | Type |
|----------------|---------------------------------------------------------------------------------------------|
| onReconnecting | `fn:({attemptNumber: number, remainingTries: number, error: Error})` |
| delay | `number` |
| delay | `{ delay: number, factor: number, max?: number, min?: number }` |
| delay | `fn: ({attemptNumber: number, remainingTries: number, error: Error}) => number | Promise` |
| shouldRetry | `fn: ({attemptNumber: number, remainingTries: number, error: Error}) => booleaan |Promise` |
| retry | `number` |
### **observePromise**
It wraps promises to observe the status. You can get if the promise `fulfilled`, `rejected` or `pending`. It's beneficial on test purposes.
```js
const observed = observePromise(fetch('http://google.com'))
console.log(observed.isPending()) // > true
console.log(observed.isRejected()) // > false
console.log(observed.isFulfilled()) // > false
console.log(observed.status) // > 'PENDING'
observed
.then(result=> {
console.log(observed.status) // > 'RESOLVED'
console.log(observed.isFulfilled()) // > true
})
.catch(() => {
console.log(observed.status) // > 'REJECTED'
console.log(observed.isRejected()) // > true
})
```
### **wait**
Creates a promise to resolve for the given time long.
```js
const printMessage = (count=0) =>
Promise.resolve()
.then(() => console.log(`You will see this message every second(${count})`))
.then(() => wait(1000).then(() => printMessage(count + 1)))
printMessage()
// > You will see this message every second(0)
// > You will see this message every second(1)
// > You will see this message every second(2)
// > You will see this message every second(3)
// > ...
```
### **timeout**
You don't need an exclusive timeout function for timeout. Use `wait` with [ES Promise.race](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/race) instead.
```js
// fail in 1 sec
Promise.race([
fetch('https://www.mocky.io/v2/5185415ba171ea3a00704eed?mocky-delay=1200ms').then(res=> resp.json()),
wait(1000).then(()=> Promise.reject('Timeout!'))
])
// > Uncaught (in promise) Timeout!
```
```js
// will mock response if the first request doesn't resolve in 1 sec
const result = await Promise.race([
fetch('https://www.mocky.io/v2/5185415ba171ea3a00704eed?mocky-delay=1200ms').then(res=> resp.json()),
wait(1000).then(()=> ({ hello: 'mock' }))
])
console.log(result)
// > { hello: 'mock' }
```
## Changelog
All notable changes to this project will be documented in the [changelog file](https://github.com/mkg0/promise-effects/blob/master/CHANGELOG.md).