fixup! Fix camera permissions race condition

Convert checkAndRequestPermission to ThunkAction that dispatches Redux updates, per swansontec comment:

"We don't want to track state locally in the component - that's the job of the permission subsystem. The problem is that the permission subsystem is modifying things and then forgetting to update redux."

Author: Jon-edge

src/components/modals/ScanModal.tsx

@@ -17,7 +17,7 @@ import { sprintf } from 'sprintf-js'
 import { useLayout } from '../../hooks/useLayout'
 import { lstrings } from '../../locales/strings'
 import { config } from '../../theme/appConfig'
-import { useSelector } from '../../types/reactRedux'
+import { useDispatch, useSelector } from '../../types/reactRedux'
 import { triggerHaptic } from '../../util/haptic'
 import { logActivity } from '../../util/logger'
 import { ModalButtons } from '../buttons/ModalButtons'
@@ -62,6 +62,7 @@ export const ScanModal: React.FC<Props> = props => {
     scanModalTitle
   } = props
 
+  const dispatch = useDispatch()
   const theme = useTheme()
   const styles = getStyles(theme)
 
@@ -90,7 +91,7 @@ export const ScanModal: React.FC<Props> = props => {
   // Mount effects
   React.useEffect(() => {
     setScanEnabled(true)
-    checkAndRequestPermission('camera')
+    dispatch(checkAndRequestPermission('camera'))
       .then(status => {
         setCameraPermission(status)
       })
@@ -100,7 +101,7 @@ export const ScanModal: React.FC<Props> = props => {
     return () => {
       setScanEnabled(false)
     }
-  }, [])
+  }, [dispatch])
 
   const handleBarCodeRead = (codes: Code[]): void => {
     setScanEnabled(false)

src/components/services/PermissionsManager.tsx

@@ -90,14 +90,22 @@ export async function requestContactsPermission(
  * Checks permission and attempts to request permissions (only if checked
  * permission was 'denied')
  */
-export async function checkAndRequestPermission(
-  data: Permission
-): Promise<PermissionStatus> {
-  const status: PermissionStatus = await check(permissionNames[data])
-
-  if (status === 'denied') return await request(permissionNames[data])
-  else return status
-}
+export const checkAndRequestPermission =
+  (permission: Permission): ThunkAction<Promise<PermissionStatus>> =>
+  async dispatch => {
+    const status: PermissionStatus = await check(permissionNames[permission])
+
+    if (status !== 'denied') return status
+
+    const newStatus = await request(permissionNames[permission])
+    if (newStatus !== status) {
+      dispatch({
+        type: 'PERMISSIONS/UPDATE',
+        data: { [permission]: newStatus }
+      })
+    }
+    return newStatus
+  }
 
 export const checkIfDenied = (status: PermissionStatus) =>
   status === 'blocked' || status === 'denied' || status === 'unavailable'
@@ -126,7 +134,7 @@ export async function requestPermissionOnSettings(
 
   // User first time check. If mandatory, it needs to be checked if denied or accepted
   if (status === 'denied') {
-    const result = await checkAndRequestPermission(data)
+    const result = await request(permissionNames[data])
     return mandatory && checkIfDenied(result)
   }