✨ Introducing `ts-belt` v4 (release candidate)

hello there! 👋

I have been working on the new version of ts-belt with support for Async* modules for a quite long time, and now I feel it’s a great time to publish (at least) a release candidate version. It’s also an excellent opportunity to gather feedback from you 😃 The bad news is, the docs for these modules are missing at the moment (I’m working on it!), but let me describe the essentials of each module:

Installation

yarn add @mobily/ts-belt@next

AsyncData

AsyncData contains a variant type for representing the different states in which a value can be during an asynchronous data load.

There are four possible states: Init, Loading, Reloading, and Complete.

type AsyncData<T> = Init | Loading | Reloading<T> | Complete<T>

import { AD } from '@mobily/ts-belt'

Variant constructors:

• AD.Init
• AD.Loading
• AD.Reloading(value)
• AD.Complete(value)
• AD.makeInit()
• AD.makeLoading()
• AD.makeReloading(value)
• AD.makeComplete(value)

Functions:

• AD.isInit
• AD.isLoading
• AD.isReloading
• AD.isComplete
• AD.isBusy
• AD.isIdle
• AD.isEmpty
• AD.isNotEmpty
• AD.toBusy
• AD.toIdle
• AD.getValue
• AD.getWithDefault
• AD.getReloading
• AD.getComplete
• AD.map
• AD.mapWithDefault
• AD.flatMap
• AD.tapInit
• AD.tapLoading
• AD.tapReloading
• AD.tapComplete
• AD.tapEmpty
• AD.tapNotEmpty
• AD.all
• AD.fold

Example: https://codesandbox.io/s/cool-star-6m87kk?file=/src/App.tsx

AsyncDataResult

AsyncDataResult is basically an alias of AsyncData<Result<Ok, Error>>. This variant type can be used to represent the different states in which a data value can exist while being loaded asynchronously, with the possibility of either success or failure.

type AsyncDataResult<A, B> = AsyncData<Result<A, B>>

import { ADR } from '@mobily/ts-belt'

Variant constructors:

• ADR.Init
• ADR.Loading
• ADR.ReloadingOk(value)
• ADR.ReloadingError(error)
• ADR.CompleteOk(value)
• ADR.CompleteError(error)
• ADR.makeInit()
• ADR.makeLoading()
• ADR.makeReloadingOk(value)
• ADR.makeReloadinError(error)
• ADR.makeCompleteOk(value)
• ADR.makeCompleteError(error)

Functions:

• ADR.isOk
• ADR.isError
• ADR.isReloadingOk
• ADR.isReloadingError
• ADR.isCompleteOk
• ADR.isCompleteError
• ADR.getOk
• ADR.getReloadingOk
• ADR.getCompleteOk
• ADR.getError
• ADR.getReloadingError
• ADR.getCompleteError
• ADR.map
• ADR.mapError
• ADR.flatMap
• ADR.tap
• ADR.fold
• ADR.foldOk
• ADR.toAsyncData

Example: https://codesandbox.io/s/brave-cloud-ov30h7?file=/src/App.tsx

AsyncOption

Same as Option but for handling asynchronous operations.

type AsyncOption<T> = Promise<Option<T>>

import { AO } from '@mobily/ts-belt'

Variant constructors:

• AO.make(promise)
• AO.resolve(value)
• AO.reject()

Functions:

• AO.filter
• AO.map
• AO.flatMap
• AO.fold
• AO.mapWithDefault
• AO.match
• AO.toNullable
• AO.toUndefined
• AO.toResult
• AO.getWithDefault
• AO.isNone
• AO.isSome
• AO.tap
• AO.contains
• AO.flatten

AsyncResult

Same as Result but for handling asynchronous operations.

type AsyncResult<A, B> = Promise<Result<A, B>>

import { AR } from '@mobily/ts-belt'

Variant constructors:

• AR.make(promise)
• AR.resolve(value)
• AR.reject(error)

Functions:

• AR.flatMap
• AR.fold
• AR.map
• AR.mapWithDefault
• AR.getWithDefault
• AR.filter
• AR.match
• AR.toNullable
• AR.toOption
• AR.toUndefined
• AR.isOk
• AR.isError
• AR.tap
• AR.tapError
• AR.handleError
• AR.mapError
• AR.catchError
• AR.recover
• AR.flip
• AR.flatten

Minor changes

• ✨ added A.sample (gets a random element from provided array)
• ✨ added O.all (transforms an array of Option(s) into a single Option data type)
• ✨ added R.all (transforms an array of Result(s) into a single Result data type)
• ✨ added R.filter (returns Ok(value) if result is Ok(value) and the result of predicateFn is truthy, otherwise, returns Error)
• 🐛 fixed up the groupBy signature

Breaking changes

ts-belt@v4 does not support Flow, due to a lack of proper features in flowgen, sorry about that!

Feel free to post your thoughts, any kind of feedback would be greatly appreciated! 💪

[Nodonisko]

Looks good, but I am starting to get lost in all that shortcuts AD, ADR, AO… Did you thinked about shipping also “non-shortcut” version of these?

[lulldev]

How about alternative match/with from ts-pattern out of box? something like fold but for handling all or each states?