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Reatom

Debugging

For debugging we recommend @reatom/logger package (included in @reatom/framework)

Installation

Terminal window
npm i @reatom/logger

After install finished you need to connect logger to reatom context

import { createCtx } from '@reatom/core'
import { connectLogger } from '@reatom/logger'


const ctx = createCtx()
connectLogger(ctx)

More settings you can found in @reatom/logger documentation

Usage

Immutable nature of Reatom give us incredible possibilities for debugging any data flow kind: synchronous and asynchronous.
Let’s start from simple example.

import { createCtx, atom } from '@reatom/core'
import { connectLogger } from '@reatom/logger'


const ctx = createCtx()
connectLogger(ctx)


const counterAtom = atom(0)
const doubledAtom = atom((ctx) => counterAtom * 2)


counterAtom(ctx, 24)

This is what we see in logs:

Reatom 1 transaction
├─ 3:37:34 PM 477ms
├─ counterAtom
│  ├─ cause: "root"
│  ├─ history: [...]
│  ├─ newState: 0
│  ├─ oldState: 24
│  ├─ patch: {...}
│  └─ time: 275.94
├─ 24
├─ doubledAtom
│  ├─ cause: "<-- counterAtom"
│  ├─ history: [...]
│  ├─ newState: 0
│  ├─ oldState: 48
│  ├─ patch: {...}
│  └─ time: 275.96
└─ 48

Records comes in pairs: atom and new state value. Under atom name record you can found few properties:

  • cause - describe why this update happens, why trigger it
  • history - atom values that was before update

More complex example you can find in @reatom/logger package documentation