Light Observable

Standard implementation of Observables for JavaScript. Requires a Promise polyfill.

• Features
• Installation
• Usage
• Motivation
• Extras
  • Consume
  • Create
  • Transform
  • Filter
  • Combine
  • Combine higher-order streams
  • Slice
  • Handle errors
  • Rate limit
  • Delay
• Notice on interoperability
• Credits
• License

Features

• Standard: fully compatible with the Observable Proposal.
• Tiny: Observable itself is ~1 kilobyte in gzip (including symbol-observable package). The whole library including ~80 operators and observable utilities is less than 6kb in gzip.
• Type-safe: written in typescript.
• Reliable: 100% unit test coverage.
• Moderate: only standard methods are included to the Observable and Observable prototype + special Observable.prototype.pipe method that allows usage of pipeable operators.
• Universal: every observable operator is available as an observable creator function. Every observable utility is compatible with any standard observable implementation like RxJS, zen-observable, etc.
• Documented: see the docs!

Installation

npm install light-observable

Usage

import { Observable } from 'light-observable'
const o = new Observable(observer => {
  observer.next(1)
  observer.next(2)
  observer.complete()
})
o.subscribe(console.log)
// > 1
// > 2

See Observable proposal for other examples.

Motivation

Because sometimes you just don’t need all these tons of classes, dozens of schedulers and countless operators. Only some of them. Someday.

Extras

See the docs to learn about ~80 operators and observable utilities included in this library.

Full list of extras:

Consume

• forEach
• drain
• reduce
• toArray

Create

• of
• from
• fromEvent
• fromPromise
• interval
• defer
• empty
• never
• createSubject

Transform

• map
• mapTo
• pairwise
• scan
• startWith
• groupBy
• tap

Filter

• filter
• reject
• partition
• skipRepeats

Combine

• concat
• combineLatest
• merge
• sample

Combine higher-order streams

• mergeAll
• mergeMap
• mergeMapTo
• switchAll
• switchMap
• switchMapTo

Slice

• slice
• skip
• skipLast
• skipUntil
• take
• takeLast

Handle errors

• catchError
• throwError
• timeout

Rate limit

• auditTime
• debounceTime
• throttleTime

Delay

• delay

Notice on interoperability

RxJS 6 doesn’t use ‘symbol-observable’ polyfill. This may cause some weird issues with interop depending on the import order. It is recommended to install and import symbol-observable polyfill before RxJS.

See the issue for details.

Credits

Originally this was forked from zen-observable. Some of extras are inspired by observable-operators.

License

Copyright 2018 Tinkoff Bank
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
   http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.