fix(transactions): persist the source filter per company and stop the reset race (#1726)

The source filter was persisted under a browser-wide v1 key (#1105), but the stale-filter guard added in #1124 compared the restored value against sourceItems before cash accounts, skattekonto rows, and transactions had loaded, so every mount reset the in-memory filter back to 'Alla källor' while storage kept the old choice: restore-then-reset on every visit. - New pure helper components/transactions/source-filter-storage.ts: per-company v2 key, isSourceFilter moved out of the page, read/write helpers (read removes the retired v1 key once), and resolveEffectiveSourceFilter. - page.tsx keeps sourceFilter as the WANTED filter, restored per company (with a state-only ?source= URL override that is never written to storage); the guard effect is replaced by a derived effectiveSourceFilter memo used by every consumer, so a source that is still loading or went stale shows 'all' without destroying the choice. - ?highlight= deep links widen to 'all' in memory when the wanted filter would hide the highlighted row. - Unit tests for the helper; no i18n changes, no migrations. Co-authored-by: Jakob Wennberg <311770904+jakobwennberg-oss@users.noreply.github.com> Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
2026-08-20 10:08:40 +02:00
parent 3de5dee553
commit b77af371c4
4 changed files with 297 additions and 100 deletions
@@ -1092,3 +1092,4 @@ One line per decision: `[YYYY-MM-DD] <decision>: <why>`. Appended by agents and
 [2026-08-19] Hem build-assistant hero downgraded to the quiet-sentence pattern (AgentPromo, matches SkatteverketPromoCard; founder direction 2026-08-18 'redesign first, maybe remove later'): dismissal is per-company localStorage (erp_agent_promo_dismissed:<companyId>) like the SKV promo, gate and hasAi/billing routing unchanged.
 [2026-08-19] Banking settings UI state derives from a pure helper (extensions/general/enable-banking/lib/connection-state.ts), not inline JSX conditions: sort precedence, the single page-level .attn sentence, and each row's one primary action must agree on which state a connection is in, and only a pure module can unit-test that. The same-bank connect intercept excludes 'pending' rows (an in-flight authorization is not a renewable connection) and the fresh-connect body sends force_new: true after the intercept so the parallel 409 server guard can distinguish deliberate second connections; 'pending' rows now render as a spinner row ("Väntar på banken") for their whole lifetime instead of only locking the connect button for 30 s, since an invisible in-flight row was the confusion.
 [2026-08-19] Bank reconnect supersede reuses status 'revoked' plus a new superseded_by column instead of a new status value, and re-points transactions.bank_connection_id to the superseding row: every existing filter, ledger-claim release, and cron skip already handles 'revoked' correctly (no CHECK-constraint migration on a live table), superseded_by disambiguates a supersede from a user disconnect, and re-pointing the feed rows (plain FK metadata, never journal tables) is what makes the picker's gap-fill probe and per-connection scoping survive a renewal.
+[2026-08-19] /transactions source filter persists in per-company localStorage (v2 key) rather than user_preferences.ui_state, matching the FyPicker/JournalEntryList page-scoped filter idiom (design rule 9 reserves ui_state for split-button modes/nav), and a derived effectiveSourceFilter memo replaces the stale-filter reset-guard effect: the guard raced the async cashAccounts/skvRows/transactions loads on every mount and wiped the restored choice back to 'Alla källor'.
@@ -47,6 +47,12 @@ import type {
  PotentialVoucher,
 } from '@/components/transactions/transaction-types'
 import { SuggestionReviewList } from '@/components/transactions/SuggestionReviewList'
+import {
+  isSourceFilter,
+  readStoredSourceFilter,
+  resolveEffectiveSourceFilter,
+  writeStoredSourceFilter,
+} from '@/components/transactions/source-filter-storage'
 import type {
  SkattekontoBatchResult,
  SkattekontoBatchRowResult,
@@ -124,8 +130,6 @@ const TemplatePicker = dynamic(() => import('@/components/transactions/TemplateP
 type InvoiceWithCustomer = Invoice & { customer?: Customer }
 type SupplierInvoiceWithSupplier = SupplierInvoice & { supplier?: Supplier }

-const SOURCE_FILTER_STORAGE_KEY = 'Accounted:transaction-source-filter:v1'
-
 // Page-local fiscal-year scope (FyPicker appends the company id). Deliberately
 // NOT the shared report scope (Accounted:fiscal-year:): a year picked on a
 // report page must never silently hide pending inbox rows here, and vice versa.
@@ -137,18 +141,6 @@ const PERIOD_FILTER_STORAGE_PREFIX = 'Accounted:transactions-fy-scope:v1:'
 // /api/documents/counts.
 const UUID_RE = /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i

-// Validates a persisted value. Stale acct:<id> entries (account removed or
-// disabled) are caught later by the sourceItems stale-filter guard.
-function isSourceFilter(value: string | null): value is SourceFilter {
-  return (
-    value === 'all' ||
-    value === 'bank' ||
-    value === 'bank:other' ||
-    value === 'skatteverket' ||
-    (value?.startsWith('acct:') ?? false)
-  )
-}
-
 // A skattekonto row qualifies for bulk booking when the outcome is fully
 // deterministic: a rule matched (booking_suggestion), it is not a likely
 // duplicate (match_suggestion), it is unbooked, and it has actually happened
@@ -305,6 +297,7 @@ interface QuickReviewState {
 export default function TransactionsPage() {
  const { company } = useCompany()
  const companyId = company?.id ?? null
+  const searchParams = useSearchParams()
  const t = useTranslations('transactions')
  const [transactions, setTransactions] = useState<TransactionWithInvoice[]>([])
  const [isLoading, setIsLoading] = useState(true)
@@ -477,28 +470,27 @@ export default function TransactionsPage() {
  // ever visit the settings panel where the reconnect prompt lives.
  const [skvNeedsReconnect, setSkvNeedsReconnect] = useState(false)

-  // One browser-wide source filter, persisted (#1105) so the choice
-  // survives reloads. Defaults to 'all'.
+  // The user's WANTED source filter, persisted per company (#1105, per-company
+  // since v2). What the page actually filters by is the derived
+  // effectiveSourceFilter below, which falls back to 'all' while the wanted
+  // source's items are still loading or when the source went stale.
  const [sourceFilter, setSourceFilter] = useState<SourceFilter>('all')

  useEffect(() => {
-    try {
-      const stored = window.localStorage.getItem(SOURCE_FILTER_STORAGE_KEY)
-      if (isSourceFilter(stored)) setSourceFilter(stored)
-    } catch {
-      // localStorage may be unavailable. Keep the default in-memory state.
-    }
-  }, [])
+    if (!companyId) return
+    // A valid ?source= deep link overrides the remembered choice for this
+    // visit only: it is applied to state, never written to storage.
+    const urlSource = searchParams.get('source')
+    setSourceFilter(isSourceFilter(urlSource) ? urlSource : readStoredSourceFilter(companyId))
+  }, [companyId, searchParams])

-  const handleSourceFilterChange = useCallback((next: SourceFilter) => {
-    setSourceFilter(next)
-
-    try {
-      window.localStorage.setItem(SOURCE_FILTER_STORAGE_KEY, next)
-    } catch {
-      // localStorage may be unavailable. The in-memory filter still works.
-    }
-  }, [])
+  const handleSourceFilterChange = useCallback(
+    (next: SourceFilter) => {
+      setSourceFilter(next)
+      if (companyId) writeStoredSourceFilter(companyId, next)
+    },
+    [companyId],
+  )

  // Period filter (rakenskapsar). FyPicker owns the persistence under the
  // page-local key. Quarter chips existed briefly (#1545) but were dropped:
@@ -543,7 +535,6 @@ export default function TransactionsPage() {
  // Bank transaction being moved to another cash account (null = dialog closed).
  const [moveAccountTarget, setMoveAccountTarget] = useState<TransactionWithInvoice | null>(null)
  const supabase = useRealtimeSupabase()
-  const searchParams = useSearchParams()
  const highlightId = searchParams.get('highlight')
  // Tracks the last highlight target we acted on so re-renders don't re-trigger
  // the auto-open every time the user closes the categorize panel.
@@ -642,59 +633,6 @@ export default function TransactionsPage() {
    [skvUnmatched, uncategorizedTransactions],
  )

-  const inboxItems = useMemo<InboxItem[]>(() => {
-    const items: InboxItem[] = []
-    const query = searchTerm.trim().toLowerCase()
-    if (sourceFilter !== 'skatteverket') {
-      for (const tx of uncategorizedTransactions) {
-        // The refetch already narrows state server-side; this check makes the
-        // filter correct immediately on change, before the refetch lands.
-        if (!isWithinBounds(tx.date, periodBounds)) continue
-        if (
-          sourceFilter.startsWith('acct:') &&
-          tx.cash_account_id !== sourceFilter.slice('acct:'.length)
-        ) {
-          continue
-        }
-        if (sourceFilter === 'bank:other' && tx.cash_account_id != null) continue
-        if (
-          query &&
-          !tx.description?.toLowerCase().includes(query) &&
-          !tx.date.includes(query) &&
-          !String(tx.amount).includes(query)
-        ) {
-          continue
-        }
-        items.push({ source: 'bank', date: tx.date, data: tx })
-      }
-    }
-    if (sourceFilter === 'all' || sourceFilter === 'skatteverket') {
-      // Inbox only shows SKV rows that need action (no verifikat yet).
-      for (const r of skvRows) {
-        // Exiting rows stay rendered for the exit animation, even if a
-        // refetch already gave them a journal_entry_id mid-window (see above).
-        if (r.journal_entry_id && !exitingIds.has(r.id)) continue
-        // SKV rows live client-side only, so the period filter applies here.
-        if (!isWithinBounds(r.transaktionsdatum, periodBounds)) continue
-        if (
-          query &&
-          !r.transaktionstext?.toLowerCase().includes(query) &&
-          !r.transaktionsdatum.includes(query) &&
-          !String(r.belopp_skatteverket).includes(query)
-        ) {
-          continue
-        }
-        items.push({ source: 'skatteverket', date: r.transaktionsdatum, data: r })
-      }
-    }
-    return items.sort((a, b) => {
-      if (a.date !== b.date) return b.date.localeCompare(a.date)
-      // Same date → bank first so invoice-match cards lead.
-      if (a.source !== b.source) return a.source === 'bank' ? -1 : 1
-      return 0
-    })
-  }, [exitingIds, periodBounds, searchTerm, skvRows, sourceFilter, uncategorizedTransactions])
-
  // History shows only the contiguous newest-first window: the older pending
  // rows merged in for the inbox would otherwise render as sparse, gap-ridden
  // months below the window and read as missing bookkeeping. Same-date rows at
@@ -793,13 +731,76 @@ export default function TransactionsPage() {
    return items
  }, [cashAccounts, hasUnassignedBankRows, skvNeedsReconnect, skvRows.length, t, totalSourceBalance])

-  // A narrowed filter can go stale (account disabled, skv rows drained,
-  // "övriga" bucket emptied): fall back to everything rather than filtering
-  // the inbox down to an invisible source.
-  useEffect(() => {
-    if (sourceFilter === 'all') return
-    if (!sourceItems.some((item) => item.id === sourceFilter)) setSourceFilter('all')
-  }, [sourceFilter, sourceItems])
+  // What the page actually filters by. A narrowed filter whose source is not
+  // (yet) among the items, because cash accounts / skv rows / transactions
+  // are still loading, or because the source went stale (account disabled,
+  // skv rows drained, "övriga" bucket emptied), resolves to 'all' instead of
+  // filtering the inbox down to an invisible source. Deriving this (rather
+  // than resetting state, as the old guard effect did) removes the mount-time
+  // race that wiped the persisted choice before the async sources arrived.
+  const effectiveSourceFilter = useMemo(
+    () =>
+      resolveEffectiveSourceFilter(
+        sourceFilter,
+        sourceItems.map((item) => item.id),
+      ),
+    [sourceFilter, sourceItems],
+  )
+
+  // Declared after sourceItems/effectiveSourceFilter because the inbox must
+  // filter by the EFFECTIVE source, never the raw wanted one.
+  const inboxItems = useMemo<InboxItem[]>(() => {
+    const items: InboxItem[] = []
+    const query = searchTerm.trim().toLowerCase()
+    if (effectiveSourceFilter !== 'skatteverket') {
+      for (const tx of uncategorizedTransactions) {
+        // The refetch already narrows state server-side; this check makes the
+        // filter correct immediately on change, before the refetch lands.
+        if (!isWithinBounds(tx.date, periodBounds)) continue
+        if (
+          effectiveSourceFilter.startsWith('acct:') &&
+          tx.cash_account_id !== effectiveSourceFilter.slice('acct:'.length)
+        ) {
+          continue
+        }
+        if (effectiveSourceFilter === 'bank:other' && tx.cash_account_id != null) continue
+        if (
+          query &&
+          !tx.description?.toLowerCase().includes(query) &&
+          !tx.date.includes(query) &&
+          !String(tx.amount).includes(query)
+        ) {
+          continue
+        }
+        items.push({ source: 'bank', date: tx.date, data: tx })
+      }
+    }
+    if (effectiveSourceFilter === 'all' || effectiveSourceFilter === 'skatteverket') {
+      // Inbox only shows SKV rows that need action (no verifikat yet).
+      for (const r of skvRows) {
+        // Exiting rows stay rendered for the exit animation, even if a
+        // refetch already gave them a journal_entry_id mid-window (see above).
+        if (r.journal_entry_id && !exitingIds.has(r.id)) continue
+        // SKV rows live client-side only, so the period filter applies here.
+        if (!isWithinBounds(r.transaktionsdatum, periodBounds)) continue
+        if (
+          query &&
+          !r.transaktionstext?.toLowerCase().includes(query) &&
+          !r.transaktionsdatum.includes(query) &&
+          !String(r.belopp_skatteverket).includes(query)
+        ) {
+          continue
+        }
+        items.push({ source: 'skatteverket', date: r.transaktionsdatum, data: r })
+      }
+    }
+    return items.sort((a, b) => {
+      if (a.date !== b.date) return b.date.localeCompare(a.date)
+      // Same date → bank first so invoice-match cards lead.
+      if (a.source !== b.source) return a.source === 'bank' ? -1 : 1
+      return 0
+    })
+  }, [effectiveSourceFilter, exitingIds, periodBounds, searchTerm, skvRows, uncategorizedTransactions])

  // Rows the bulkbar's "Markera alla" can select: the visible bank rows
  // (they feed the /api/transactions/* batch handlers) ...
@@ -1409,6 +1410,21 @@ export default function TransactionsPage() {
    if (!tx) return
    handledHighlightRef.current = highlightId

+    // A deep link must land on a visible row: when the remembered source
+    // filter would hide the highlighted transaction, widen to 'all' in
+    // memory only (storage keeps the user's choice for the next visit).
+    // Checked against the WANTED filter, not the effective one: transactions
+    // can load before cash accounts, when the effective filter is still 'all'
+    // but the wanted one would hide the row the moment the accounts arrive.
+    // 'all' rather than acct:<id> because it also covers rows with a null
+    // cash_account_id.
+    const hiddenByFilter =
+      sourceFilter === 'skatteverket' ||
+      (sourceFilter.startsWith('acct:') &&
+        tx.cash_account_id !== sourceFilter.slice('acct:'.length)) ||
+      (sourceFilter === 'bank:other' && tx.cash_account_id != null)
+    if (hiddenByFilter) setSourceFilter('all')
+
    // Defer the scroll until React has committed the list to the DOM.
    // Without rAF the data-tx-id node may not exist yet when this fires
    // immediately after fetchTransactions resolves.
@@ -1420,7 +1436,7 @@ export default function TransactionsPage() {
        }
      })
    })
-  }, [highlightId, transactions])
+  }, [highlightId, sourceFilter, transactions])

  // Auto-fetch suggestions when transactions load
  useEffect(() => {
@@ -3470,7 +3486,7 @@ export default function TransactionsPage() {
      <TransactionStatusBar onOpenCreateDialog={() => setIsDialogOpen(true)} />


-      {skvNeedsReconnect && sourceFilter === 'skatteverket' ? (
+      {skvNeedsReconnect && effectiveSourceFilter === 'skatteverket' ? (
        // Only when the user is actually looking at skattekonto rows: as a
        // permanent page-wide line it read as noise (feedback 2026-08-14).
        // The skattekonto page keeps its own reconnect line.
@@ -3534,11 +3550,11 @@ export default function TransactionsPage() {
          />
          {sourceItems.length > 1 && (
            <ContextPicker
-              value={sourceFilter}
+              value={effectiveSourceFilter}
              onChange={(id) => handleSourceFilterChange(id as SourceFilter)}
              triggerLabel={(() => {
                const active =
-                  sourceItems.find((item) => item.id === sourceFilter) ?? sourceItems[0]
+                  sourceItems.find((item) => item.id === effectiveSourceFilter) ?? sourceItems[0]
                return active.annotation ? `${active.label} · ${active.annotation}` : active.label
              })()}
              items={sourceItems}
@@ -3572,13 +3588,13 @@ export default function TransactionsPage() {
        />
      ) : mode === 'inbox' ? (
        inboxItems.length === 0 ? (
-          searchTerm || sourceFilter !== 'all' || periodBounds ? (
+          searchTerm || effectiveSourceFilter !== 'all' || periodBounds ? (
            <DataListEmpty
              title="Inga träffar"
              description={
                searchTerm
                  ? t('no_search_results')
-                  : sourceFilter !== 'all'
+                  : effectiveSourceFilter !== 'all'
                    ? t('source_empty')
                    : t('period_empty')
              }
@@ -3761,7 +3777,7 @@ export default function TransactionsPage() {
          skvRows={skvRowsInScope}
          exitingIds={exitingIds}
          searchTerm={searchTerm}
-          sourceFilter={sourceFilter}
+          sourceFilter={effectiveSourceFilter}
          jeUnderlagStatus={jeUnderlagStatus}
          onOpenMatchDialog={openMatchDialog}
          onOpenCategoryDialog={openCategoryDialog}
@@ -0,0 +1,122 @@
+import { describe, it, expect, vi, afterEach } from 'vitest'
+import {
+  SOURCE_FILTER_STORAGE_PREFIX,
+  isSourceFilter,
+  readStoredSourceFilter,
+  writeStoredSourceFilter,
+  resolveEffectiveSourceFilter,
+} from '@/components/transactions/source-filter-storage'
+
+const LEGACY_KEY = 'Accounted:transaction-source-filter:v1'
+
+function stubLocalStorage(initial: Record<string, string> = {}) {
+  const store = new Map<string, string>(Object.entries(initial))
+  const localStorage = {
+    getItem: (key: string) => store.get(key) ?? null,
+    setItem: (key: string, value: string) => {
+      store.set(key, value)
+    },
+    removeItem: (key: string) => {
+      store.delete(key)
+    },
+  }
+  vi.stubGlobal('window', { localStorage })
+  return store
+}
+
+afterEach(() => {
+  vi.unstubAllGlobals()
+})
+
+describe('isSourceFilter', () => {
+  it('accepts every member of the SourceFilter union', () => {
+    expect(isSourceFilter('all')).toBe(true)
+    expect(isSourceFilter('bank')).toBe(true)
+    expect(isSourceFilter('bank:other')).toBe(true)
+    expect(isSourceFilter('skatteverket')).toBe(true)
+    expect(isSourceFilter('acct:2f8d1c3a')).toBe(true)
+  })
+
+  it('rejects null and unknown values', () => {
+    expect(isSourceFilter(null)).toBe(false)
+    expect(isSourceFilter('')).toBe(false)
+    expect(isSourceFilter('everything')).toBe(false)
+    expect(isSourceFilter('account:123')).toBe(false)
+    expect(isSourceFilter('ALL')).toBe(false)
+  })
+})
+
+describe('resolveEffectiveSourceFilter', () => {
+  it('keeps the wanted filter when its id is among the items', () => {
+    expect(resolveEffectiveSourceFilter('acct:a1', ['all', 'acct:a1', 'skatteverket'])).toBe(
+      'acct:a1',
+    )
+    expect(resolveEffectiveSourceFilter('skatteverket', ['all', 'skatteverket'])).toBe(
+      'skatteverket',
+    )
+  })
+
+  it('falls back to all when the wanted id is missing (items still loading or source stale)', () => {
+    expect(resolveEffectiveSourceFilter('acct:a1', ['all'])).toBe('all')
+    expect(resolveEffectiveSourceFilter('skatteverket', ['all', 'acct:a1'])).toBe('all')
+    expect(resolveEffectiveSourceFilter('bank:other', ['all', 'acct:a1'])).toBe('all')
+  })
+
+  it('passes all through regardless of items', () => {
+    expect(resolveEffectiveSourceFilter('all', [])).toBe('all')
+    expect(resolveEffectiveSourceFilter('all', ['all', 'acct:a1'])).toBe('all')
+  })
+})
+
+describe('readStoredSourceFilter / writeStoredSourceFilter', () => {
+  it('round-trips a filter under the per-company key', () => {
+    stubLocalStorage()
+    writeStoredSourceFilter('company-a', 'acct:a1')
+    expect(readStoredSourceFilter('company-a')).toBe('acct:a1')
+  })
+
+  it('keeps companies separate: one company never reads another company value', () => {
+    stubLocalStorage()
+    writeStoredSourceFilter('company-a', 'acct:a1')
+    writeStoredSourceFilter('company-b', 'skatteverket')
+    expect(readStoredSourceFilter('company-a')).toBe('acct:a1')
+    expect(readStoredSourceFilter('company-b')).toBe('skatteverket')
+    expect(readStoredSourceFilter('company-c')).toBe('all')
+  })
+
+  it('returns all when the stored value is invalid', () => {
+    stubLocalStorage({ [SOURCE_FILTER_STORAGE_PREFIX + 'company-a']: 'garbage' })
+    expect(readStoredSourceFilter('company-a')).toBe('all')
+  })
+
+  it('returns all when localStorage throws', () => {
+    vi.stubGlobal('window', {
+      localStorage: {
+        getItem: () => {
+          throw new Error('denied')
+        },
+        setItem: () => {
+          throw new Error('denied')
+        },
+        removeItem: () => {
+          throw new Error('denied')
+        },
+      },
+    })
+    expect(readStoredSourceFilter('company-a')).toBe('all')
+    // Write must swallow the failure too.
+    expect(() => writeStoredSourceFilter('company-a', 'bank')).not.toThrow()
+  })
+
+  it('returns all when window is unavailable (SSR/node)', () => {
+    // No stub: vitest runs in the node environment, so window is undefined.
+    expect(readStoredSourceFilter('company-a')).toBe('all')
+    expect(() => writeStoredSourceFilter('company-a', 'bank')).not.toThrow()
+  })
+
+  it('removes the retired browser-wide v1 key on read and ignores its value', () => {
+    const store = stubLocalStorage({ [LEGACY_KEY]: 'skatteverket' })
+    expect(readStoredSourceFilter('company-a')).toBe('all')
+    expect(store.has(LEGACY_KEY)).toBe(false)
+  })
+})
@@ -0,0 +1,58 @@
+import type { SourceFilter } from '@/components/transactions/transaction-types'
+
+// Per-company key (v2). The v1 key was browser-wide, so an acct:<id> picked
+// under one company leaked into every other company in the same browser;
+// v2 scopes the memory per company like the FyPicker/JournalEntryList idiom.
+export const SOURCE_FILTER_STORAGE_PREFIX = 'Accounted:transaction-source-filter:v2:'
+
+// The retired browser-wide key from #1105. Removed once on read so it does
+// not linger in users' storage forever.
+const LEGACY_SOURCE_FILTER_STORAGE_KEY = 'Accounted:transaction-source-filter:v1'
+
+// Validates a persisted or URL-provided value. Stale acct:<id> entries
+// (account removed or disabled) are handled by resolveEffectiveSourceFilter,
+// which falls back to 'all' whenever the id is not among the picker items.
+export function isSourceFilter(value: string | null): value is SourceFilter {
+  return (
+    value === 'all' ||
+    value === 'bank' ||
+    value === 'bank:other' ||
+    value === 'skatteverket' ||
+    (value?.startsWith('acct:') ?? false)
+  )
+}
+
+export function readStoredSourceFilter(companyId: string): SourceFilter {
+  try {
+    // One-time cleanup of the legacy browser-wide key; v2 ignores its value.
+    window.localStorage.removeItem(LEGACY_SOURCE_FILTER_STORAGE_KEY)
+    const stored = window.localStorage.getItem(SOURCE_FILTER_STORAGE_PREFIX + companyId)
+    if (isSourceFilter(stored)) return stored
+  } catch {
+    // localStorage may be unavailable. Fall through to the default.
+  }
+  return 'all'
+}
+
+export function writeStoredSourceFilter(companyId: string, next: SourceFilter): void {
+  try {
+    window.localStorage.setItem(SOURCE_FILTER_STORAGE_PREFIX + companyId, next)
+  } catch {
+    // localStorage may be unavailable. The in-memory filter still works.
+  }
+}
+
+// The wanted filter (persisted choice or URL override) applies only while its
+// source actually exists among the picker items. While async sources
+// (cash accounts, skv rows, transactions) are still loading, or when a source
+// went stale (account disabled, skattekonto drained), the page shows 'all';
+// the wanted value stays intact so the choice springs back when the source
+// reappears. This derivation replaces the old reset-guard effect, which raced
+// the loads and permanently reset the in-memory filter on every mount.
+export function resolveEffectiveSourceFilter(
+  wanted: SourceFilter,
+  itemIds: readonly string[],
+): SourceFilter {
+  if (wanted === 'all') return 'all'
+  return itemIds.includes(wanted) ? wanted : 'all'
+}