fix(ui): persist call flow filter prefs across tabs

Remember host grouping and display toggles in localStorage (Homer 7
parity) so switching transaction tabs does not reset Group by alias.

Author: adubovikov

src/ui/src/dashboard/flow/flowFilterPrefs.test.ts

@@ -0,0 +1,49 @@
+import { describe, expect, it, beforeEach } from 'vitest'
+import {
+  FLOW_FILTER_PREFS_LS_KEY,
+  initialFlowFilters,
+  loadStoredFlowPrefs,
+  saveStoredFlowPrefs,
+} from './flowFilterPrefs'
+import { DEFAULT_FILTERS } from './flowFilterPrefs'
+
+describe('flowFilterPrefs', () => {
+  beforeEach(() => {
+    localStorage.clear()
+  })
+
+  it('round-trips host grouping and toggles', () => {
+    saveStoredFlowPrefs({
+      ...DEFAULT_FILTERS,
+      hostGrouping: 'group-by-alias',
+      isSimplify: true,
+      isAbsoluteTime: true,
+      isHighContrast: true,
+    })
+    expect(loadStoredFlowPrefs()).toEqual({
+      hostGrouping: 'group-by-alias',
+      isSimplify: true,
+      isAbsoluteTime: true,
+      isHighContrast: true,
+    })
+  })
+
+  it('ignores invalid stored host grouping', () => {
+    localStorage.setItem(
+      FLOW_FILTER_PREFS_LS_KEY,
+      JSON.stringify({ hostGrouping: 'invalid', isSimplify: true }),
+    )
+    expect(loadStoredFlowPrefs()).toEqual({ isSimplify: true })
+  })
+
+  it('initialFlowFilters merges stored prefs with empty exclusion sets', () => {
+    localStorage.setItem(
+      FLOW_FILTER_PREFS_LS_KEY,
+      JSON.stringify({ hostGrouping: 'group-by-ip' }),
+    )
+    const f = initialFlowFilters()
+    expect(f.hostGrouping).toBe('group-by-ip')
+    expect(f.ipExcluded.size).toBe(0)
+    expect(f.methodExcluded.size).toBe(0)
+  })
+})

src/ui/src/dashboard/flow/flowFilterPrefs.ts

@@ -0,0 +1,84 @@
+import type { HostGrouping } from './flow-data'
+
+export const FLOW_FILTER_PREFS_LS_KEY = 'homer_callflow_prefs'
+
+const HOST_GROUPINGS: HostGrouping[] = ['ungrouped', 'group-by-ip', 'group-by-alias']
+
+export interface FlowFilters {
+  isSimplify: boolean
+  isAbsoluteTime: boolean
+  isHighContrast: boolean
+  hostGrouping: HostGrouping
+  ipExcluded: Set<string>
+  methodExcluded: Set<string>
+  payloadTypeExcluded: Set<string>
+  callIdExcluded: Set<string>
+}
+
+export const DEFAULT_FILTERS: FlowFilters = {
+  isSimplify: false,
+  isAbsoluteTime: false,
+  isHighContrast: false,
+  hostGrouping: 'ungrouped',
+  ipExcluded: new Set(),
+  methodExcluded: new Set(),
+  payloadTypeExcluded: new Set(),
+  callIdExcluded: new Set(),
+}
+
+export interface StoredFlowPrefs {
+  hostGrouping?: HostGrouping
+  isSimplify?: boolean
+  isAbsoluteTime?: boolean
+  isHighContrast?: boolean
+}
+
+export function isHostGrouping(value: unknown): value is HostGrouping {
+  return typeof value === 'string' && (HOST_GROUPINGS as string[]).includes(value)
+}
+
+export function loadStoredFlowPrefs(): StoredFlowPrefs {
+  if (typeof localStorage === 'undefined') return {}
+  try {
+    const raw = localStorage.getItem(FLOW_FILTER_PREFS_LS_KEY)
+    if (!raw) return {}
+    const parsed = JSON.parse(raw) as StoredFlowPrefs
+    if (!parsed || typeof parsed !== 'object') return {}
+    const out: StoredFlowPrefs = {}
+    if (isHostGrouping(parsed.hostGrouping)) out.hostGrouping = parsed.hostGrouping
+    if (typeof parsed.isSimplify === 'boolean') out.isSimplify = parsed.isSimplify
+    if (typeof parsed.isAbsoluteTime === 'boolean') out.isAbsoluteTime = parsed.isAbsoluteTime
+    if (typeof parsed.isHighContrast === 'boolean') out.isHighContrast = parsed.isHighContrast
+    return out
+  } catch {
+    return {}
+  }
+}
+
+export function saveStoredFlowPrefs(filters: FlowFilters): void {
+  if (typeof localStorage === 'undefined') return
+  const payload: StoredFlowPrefs = {
+    hostGrouping: filters.hostGrouping,
+    isSimplify: filters.isSimplify,
+    isAbsoluteTime: filters.isAbsoluteTime,
+    isHighContrast: filters.isHighContrast,
+  }
+  try {
+    localStorage.setItem(FLOW_FILTER_PREFS_LS_KEY, JSON.stringify(payload))
+  } catch {
+    /* ignore quota / private mode */
+  }
+}
+
+/** UI prefs from localStorage + fresh per-call exclusion sets. */
+export function initialFlowFilters(): FlowFilters {
+  const stored = loadStoredFlowPrefs()
+  return {
+    ...DEFAULT_FILTERS,
+    ...stored,
+    ipExcluded: new Set(),
+    methodExcluded: new Set(),
+    payloadTypeExcluded: new Set(),
+    callIdExcluded: new Set(),
+  }
+}

src/ui/src/dashboard/flow/useFlowFilters.ts

@@ -1,34 +1,21 @@
-import { useMemo, useState } from 'react'
-import type { HostGrouping, RawMessage } from './flow-data'
+import { useEffect, useMemo, useState } from 'react'
+import type { RawMessage } from './flow-data'
 import { payloadTypeOf } from './flow-data'
+import {
+  DEFAULT_FILTERS,
+  initialFlowFilters,
+  saveStoredFlowPrefs,
+  type FlowFilters,
+} from './flowFilterPrefs'
+
+export type { FlowFilters } from './flowFilterPrefs'
+export { DEFAULT_FILTERS } from './flowFilterPrefs'
 
 export interface FilterToken {
   value: string
   selected: boolean
 }
 
-export interface FlowFilters {
-  isSimplify: boolean
-  isAbsoluteTime: boolean
-  isHighContrast: boolean
-  hostGrouping: HostGrouping
-  ipExcluded: Set<string>
-  methodExcluded: Set<string>
-  payloadTypeExcluded: Set<string>
-  callIdExcluded: Set<string>
-}
-
-export const DEFAULT_FILTERS: FlowFilters = {
-  isSimplify: false,
-  isAbsoluteTime: false,
-  isHighContrast: false,
-  hostGrouping: 'ungrouped',
-  ipExcluded: new Set(),
-  methodExcluded: new Set(),
-  payloadTypeExcluded: new Set(),
-  callIdExcluded: new Set(),
-}
-
 function collectUnique(items: RawMessage[], picker: (m: RawMessage) => string[]): string[] {
   const set = new Set<string>()
   items.forEach((m) => {
@@ -65,7 +52,11 @@ export interface UseFlowFiltersResult {
 }
 
 export function useFlowFilters(items: RawMessage[] | null | undefined): UseFlowFiltersResult {
-  const [filters, setFilters] = useState<FlowFilters>(DEFAULT_FILTERS)
+  const [filters, setFilters] = useState<FlowFilters>(initialFlowFilters)
+
+  useEffect(() => {
+    saveStoredFlowPrefs(filters)
+  }, [filters.hostGrouping, filters.isSimplify, filters.isAbsoluteTime, filters.isHighContrast])
 
   const { filterIP, filterMethod, filterPayloadType, filterCallId, filteredItems } = useMemo(() => {
     const safe = items ?? []