https://github.com/jcoreio/chai-wait-for

poll until an assertion succeeds
https://github.com/jcoreio/chai-wait-for

assertion async async-await await chai poll retry wait

Last synced: about 1 month ago
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poll until an assertion succeeds

• Host: GitHub
• URL: https://github.com/jcoreio/chai-wait-for
• Owner: jcoreio
• License: mit
• Created: 2020-12-17T21:29:27.000Z (about 4 years ago)
• Default Branch: master
• Last Pushed: 2024-10-16T19:23:07.000Z (2 months ago)
• Last Synced: 2024-10-18T18:19:47.506Z (2 months ago)
• Topics: assertion, async, async-await, await, chai, poll, retry, wait
• Language: JavaScript
• Size: 818 KB
• Stars: 2
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE.md

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README

        
# chai-wait-for

[![CircleCI](https://circleci.com/gh/jcoreio/chai-wait-for.svg?style=svg)](https://circleci.com/gh/jcoreio/chai-wait-for)

[![Coverage Status](https://codecov.io/gh/jcoreio/chai-wait-for/branch/master/graph/badge.svg)](https://codecov.io/gh/jcoreio/chai-wait-for)

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[![npm version](https://badge.fury.io/js/chai-wait-for.svg)](https://badge.fury.io/js/chai-wait-for)

Drop-in replacement for `expect` that waits for the assertion to succeed (retries on an interval you choose, until a timeout

you choose).

Provides an especially clean syntax for working with some chai plugins like `chai-fs`, `chai-webdriverio-async` etc:

```js

await waitFor('#submittedMessage').to.have.text('Your changes have been saved!')

```

# Usage

```sh

npm install --save-dev chai-wait-for

```

```js

// First, use the plugin

const chai = require('chai')

const chaiWaitFor = require('chai-wait-for')

chai.use(chaiWaitFor)

// Then create your `waitFor` with default options:

const waitFor = chaiWaitFor.bindWaitFor({

  // If no assertion attempt succeeds before this time elapses (in milliseconds), the waitFor will fail.

  timeout: 5000,

  // If an assertion attempt fails, it will retry after this amount of time (in milliseconds)

  retryInterval: 100,

})

it('wait for something', async function () {

  this.timeout(10000)

  const myObj = { foo: 0 }

  setInterval(() => myObj.foo++, 1000)

  // Then use it just like you would expect() (but note you must await it!)

  await waitFor(myObj).to.have.property('foo').that.equals(3)

  // You can also use a getter function:

  await waitFor(() => myObj.foo).to.equal(4)

  // If you need to override the defaults:

  await waitFor.timeout(1000)(myObj).to.have.property('foo').that.equals(3)

  await waitFor.retryInterval(500)(myObj).to.have.property('foo').that.equals(3)

})

```

# Plugin usage order/usage with `chai-as-promised`

All `chai` language chains that were defined before you use `chai-wait-for` will be available to use with it.

This is similar to `chai-as-promsied`, but although you generally need to `chai.use(require('chai-as-promised'))` after

all your other chai plugins, this is actually not the case for `chai-wait-for`, because `chai-wait-for` doesn't add or

overwrite any language chains.

Instead you should use `chai-wait-for` after `chai-as-promised`, so that you can `waitFor` `.eventually` assertions:

```js

const chai = require('chai')

const chaiWaitFor = require('chai-wait-for')

chai.use(require('chai-as-promised'))

chai.use(chaiWaitFor)

const waitFor = chaiWaitFor.bindWaitFor({ retryInterval: 100, timeout: 5000 })

it('wait for something', async function () {

  // User.findOne returns a promise; use .eventually.not.exist to wait for user to be deleted

  await waitFor(() => User.findOne({ where: { username: 'dude' } })).to

    .eventually.not.exist

})

```