Don't create new stake position map objects in useSelector

Author: peachbits

src/components/scenes/Staking/StakeOptionsScene.tsx

@@ -10,6 +10,7 @@ import { useIconColor } from '../../../hooks/useIconColor'
 import { lstrings } from '../../../locales/strings'
 import { getStakePlugins } from '../../../plugins/stake-plugins/stakePlugins'
 import type { StakePolicy } from '../../../plugins/stake-plugins/types'
+import { EMPTY_STAKE_POSITION_MAP } from '../../../reducers/StakingReducer'
 import { useSelector } from '../../../types/reactRedux'
 import type { EdgeAppSceneProps } from '../../../types/routerTypes'
 import { getCurrencyCode } from '../../../util/CurrencyInfoHelpers'
@@ -46,9 +47,10 @@ const StakeOptionsSceneComponent: React.FC<Props> = props => {
   const [stakePlugins = []] = useAsyncValue(
     async () => await getStakePlugins(wallet.currencyInfo.pluginId)
   )
-  const stakePositionMap = useSelector(
-    state => state.staking.walletStakingMap[wallet.id]?.stakePositionMap ?? {}
-  )
+  const stakePositionMap =
+    useSelector(
+      state => state.staking.walletStakingMap[wallet.id]?.stakePositionMap
+    ) ?? EMPTY_STAKE_POSITION_MAP
   const theme = useTheme()
 
   const account = useSelector(state => state.core.account)

src/components/themed/TransactionListTop.tsx

@@ -28,6 +28,7 @@ import { formatNumber, toPercentString } from '../../locales/intl'
 import { lstrings } from '../../locales/strings'
 import { getStakePlugins } from '../../plugins/stake-plugins/stakePlugins'
 import type { StakePlugin } from '../../plugins/stake-plugins/types'
+import { EMPTY_STAKE_POSITION_MAP } from '../../reducers/StakingReducer'
 import {
   getExchangeDenom,
   selectDisplayDenom
@@ -111,10 +112,10 @@ export const TransactionListTop: React.FC<Props> = props => {
   const exchangeRates = useSelector(state => state.exchangeRates)
   const defaultIsoFiat = useSelector(state => state.ui.settings.defaultIsoFiat)
   const countryCode = useSelector(state => state.ui.countryCode)
-  const stakePositionMap = useSelector(
-    // Fallback to a default state using the reducer if the wallet is not found
-    state => state.staking.walletStakingMap[wallet.id]?.stakePositionMap ?? {}
-  )
+  const stakePositionMap =
+    useSelector(
+      state => state.staking.walletStakingMap[wallet.id]?.stakePositionMap
+    ) ?? EMPTY_STAKE_POSITION_MAP
 
   const defaultFiat = removeIsoPrefix(defaultIsoFiat)
   const theme = useTheme()

src/reducers/StakingReducer.ts

@@ -72,6 +72,9 @@ export type StakePolicyMap = Record<string, StakePolicy>
 
 export type StakePositionMap = Record<string, StakePosition>
 
+export const EMPTY_STAKE_POSITION_MAP: Readonly<StakePositionMap> =
+  Object.freeze({})
+
 export const staking: Reducer<StakingState, Action> = combineReducers({
   walletStakingMap: (state = {}, action: Action) => {
     if (action.type.startsWith('STAKING/')) {