fix(ui): improve scan status handling (again) (#4115)

ui/src/layout/ActivityPanel.jsx

@@ -1,5 +1,5 @@
 import React, { useState, useEffect } from 'react'
-import { useDispatch, useSelector } from 'react-redux'
+import { useSelector } from 'react-redux'
 import { useNotify, useTranslate } from 'react-admin'
 import {
   Popover,
@@ -15,11 +15,11 @@ import {
   Typography,
 } from '@material-ui/core'
 import { FiActivity } from 'react-icons/fi'
-import { BiError, BiCheckCircle } from 'react-icons/bi'
+import { BiError } from 'react-icons/bi'
 import { VscSync } from 'react-icons/vsc'
 import { GiMagnifyingGlass } from 'react-icons/gi'
 import subsonic from '../subsonic'
-import { scanStatusUpdate } from '../actions'
+import { useInitialScanStatus } from './useInitialScanStatus'
 import { useInterval } from '../common'
 import { useScanElapsedTime } from './useScanElapsedTime'
 import { formatDuration, formatShortDuration } from '../utils'
@@ -80,24 +80,12 @@ const ActivityPanel = () => {
   const notify = useNotify()
   const [anchorEl, setAnchorEl] = useState(null)
   const open = Boolean(anchorEl)
-  const dispatch = useDispatch()
+  useInitialScanStatus()
 
   const handleMenuOpen = (event) => setAnchorEl(event.currentTarget)
   const handleMenuClose = () => setAnchorEl(null)
   const triggerScan = (full) => () => subsonic.startScan({ fullScan: full })
 
-  // Get updated status on component mount
-  useEffect(() => {
-    subsonic
-      .getScanStatus()
-      .then((resp) => resp.json['subsonic-response'])
-      .then((data) => {
-        if (data.status === 'ok') {
-          dispatch(scanStatusUpdate(data.scanStatus))
-        }
-      })
-  }, [dispatch])
-
   useEffect(() => {
     if (serverStart.version && serverStart.version !== config.version) {
       notify('ra.notification.new_version', 'info', {}, false, 604800000 * 50)

ui/src/layout/useInitialScanStatus.jsx

@@ -0,0 +1,18 @@
+import { useEffect } from 'react'
+import { useDispatch } from 'react-redux'
+import subsonic from '../subsonic'
+import { scanStatusUpdate } from '../actions'
+
+export const useInitialScanStatus = () => {
+  const dispatch = useDispatch()
+  useEffect(() => {
+    subsonic
+      .getScanStatus()
+      .then((resp) => resp.json['subsonic-response'])
+      .then((data) => {
+        if (data.status === 'ok') {
+          dispatch(scanStatusUpdate(data.scanStatus))
+        }
+      })
+  }, [dispatch])
+}

ui/src/layout/useScanElapsedTime.jsx

@@ -6,16 +6,17 @@ export const useScanElapsedTime = (scanning, elapsedTime) => {
   const prevScanningRef = useRef(scanning)
 
   useEffect(() => {
-    // Only update from server when scan starts or stops
     const prevScanning = prevScanningRef.current
-    if (!prevScanning && scanning) {
-      // Scan just started - initialize with server value
-      setElapsed(Number(elapsedTime) || 0)
-    } else if (prevScanning && !scanning) {
-      // Scan just finished - use final server value
-      setElapsed(Number(elapsedTime) || 0)
+    const serverElapsed = Number(elapsedTime) || 0
+
+    if (scanning !== prevScanning) {
+      // Scan has just started or stopped - sync with server value
+      setElapsed(serverElapsed)
+    } else if (!scanning) {
+      // Not scanning -> always reflect server value (initial load or after finish)
+      setElapsed(serverElapsed)
     }
-    // Update ref for next comparison
+
     prevScanningRef.current = scanning
   }, [scanning, elapsedTime])
 

ui/src/layout/useScanElapsedTime.test.jsx

@@ -70,6 +70,20 @@ describe('useScanElapsedTime', () => {
     expect(result.current).toBe(12e9)
   })
 
+  it('updates elapsed time when not scanning and server value changes', () => {
+    const { result, rerender } = renderHook(
+      ({ scanning, elapsed }) => useScanElapsedTime(scanning, elapsed),
+      {
+        initialProps: { scanning: false, elapsed: 0 },
+      },
+    )
+
+    // Server reports new elapsed time without changing scanning state
+    rerender({ scanning: false, elapsed: 8e9 })
+
+    expect(result.current).toBe(8e9)
+  })
+
   it('ignores server updates during scanning', () => {
     const { result, rerender } = renderHook(
       ({ scanning, elapsed }) => useScanElapsedTime(scanning, elapsed),