Align sync as per the review

.gitignore

@@ -28,6 +28,7 @@ node_modules/
 .pnpm-store/
 build/
 .svelte-kit/
+.next/
 
 # Rust/Tauri
 *target/

src/app/core/state.ts

@@ -156,24 +156,6 @@ import {readFeed} from "@lib/feeds"
 
 export const fromCsv = (s: string) => (s || "").split(",").filter(identity)
 
-// Keep sync logic informed when the tab sleeps or wakes so subscriptions can be torn down cleanly.
-export const documentVisibility = readable<DocumentVisibilityState>(
-  typeof document !== "undefined" ? document.visibilityState : "visible",
-  set => {
-    if (typeof document === "undefined") return
-
-    const onVisibilityChange = () => {
-      set(document.visibilityState)
-    }
-
-    document.addEventListener("visibilitychange", onVisibilityChange)
-
-    return () => {
-      document.removeEventListener("visibilitychange", onVisibilityChange)
-    }
-  },
-)
-
 export const ROOM = "h"
 
 export const PROTECTED = ["-"]

src/app/core/sync.ts

@@ -1,12 +1,12 @@
 import {page} from "$app/stores"
 import type {Unsubscriber} from "svelte/store"
-import {derived, get} from "svelte/store"
-import {last, call, ifLet, assoc, chunk, sleep, identity, WEEK, ago} from "@welshman/lib"
+import {get} from "svelte/store"
+import {last, call, ifLet, assoc, chunk, sleep, WEEK, ago} from "@welshman/lib"
 import {PollResponse} from "nostr-tools/kinds"
+import {merged} from "@welshman/store"
 import {
   getListTags,
   getRelayTagValues,
-  type List,
   WRAP,
   ROOM_META,
   ROOM_DELETE,
@@ -22,7 +22,7 @@ import {
   unionFilters,
   getTagValue,
 } from "@welshman/util"
-import type {Filter, TrustedEvent} from "@welshman/util"
+import type {Filter, List, PublishedList, TrustedEvent} from "@welshman/util"
 import {request, requestOne, Difference, DifferenceEvent} from "@welshman/net"
 import {
   pubkey,
@@ -46,7 +46,6 @@ import {
   MESSAGE_KINDS,
   CONTENT_KINDS,
   INDEXER_RELAYS,
-  documentVisibility,
   loadSettings,
   loadGroupList,
   userSpaceUrls,
@@ -238,7 +237,7 @@ const syncUserData = () => {
     }
   }
 
-  const syncRelayList = ($userRelayList: List | undefined) => {
+  const syncRelayList = ($userRelayList: PublishedList | undefined) => {
     const pubkey = $userRelayList?.event?.pubkey
 
     if (!pubkey) return
@@ -272,34 +271,17 @@ const syncUserData = () => {
     }
   }
 
-  const unsubscribeGroupList = derived([userGroupList, documentVisibility], identity).subscribe(
-    ([$userGroupList, $visibility]) => {
-      if ($visibility === "hidden") {
-        unsubscribersByKey.forEach(call)
-        unsubscribersByKey.clear()
+  const unsubscribeGroupList = merged([userGroupList]).subscribe(([$userGroupList]) => {
+    syncGroupList($userGroupList)
+  })
 
-        return
-      }
+  const unsubscribeRelayList = merged([userRelayList]).subscribe(([$userRelayList]) => {
+    syncRelayList($userRelayList)
+  })
 
-      syncGroupList($userGroupList)
-    },
-  )
-
-  const unsubscribeRelayList = derived([userRelayList, documentVisibility], identity).subscribe(
-    ([$userRelayList, $visibility]) => {
-      if ($visibility === "hidden") return
-
-      syncRelayList($userRelayList)
-    },
-  )
-
-  const unsubscribeFollows = derived([userFollowList, documentVisibility], identity).subscribe(
-    ([$userFollowList, $visibility]) => {
-      if ($visibility === "hidden") return
-
-      syncFollowList()
-    },
-  )
+  const unsubscribeFollows = merged([userFollowList]).subscribe(() => {
+    syncFollowList()
+  })
 
   return () => {
     unsubscribersByKey.forEach(call)
@@ -364,22 +346,11 @@ const syncSpace = (url: string, rooms: string[]) => {
 }
 
 const syncSpaces = () => {
-  const store = derived([userGroupList, page, documentVisibility], identity)
+  const store = merged([userGroupList, page])
   const unsubscribersByUrl = new Map<string, Unsubscriber>()
   const roomsByUrl = new Map<string, string>()
 
-  const unsubscribe = store.subscribe(([$userGroupList, $page, $visibility]) => {
-    if ($visibility === "hidden") {
-      // Hidden tabs should drop every live space subscription so we restart from a clean slate on wake.
-      for (const unsubscribe of unsubscribersByUrl.values()) {
-        unsubscribe()
-      }
-
-      unsubscribersByUrl.clear()
-      roomsByUrl.clear()
-      return
-    }
-
+  const unsubscribe = store.subscribe(([$userGroupList, $page]) => {
     const urls = new Set(getSpaceUrlsFromGroupList($userGroupList))
 
     if ($page.params.relay) {
@@ -438,8 +409,6 @@ const syncDMs = () => {
 
   let currentPubkey: string | undefined
   let currentShouldUnwrap = false
-  // Late relay-list promises can resolve after a hide/show cycle, so keep the last visible state here.
-  let currentVisibility: DocumentVisibilityState = "visible"
 
   const unsubscribeAll = () => {
     for (const [url, unsubscribe] of unsubscribersByUrl.entries()) {
@@ -457,12 +426,7 @@ const syncDMs = () => {
       loadRelayList($pubkey)
         .then(() => loadMessagingRelayList($pubkey))
         .then($l => {
-          if (
-            $l &&
-            currentVisibility === "visible" &&
-            currentPubkey === $pubkey &&
-            currentShouldUnwrap === $shouldUnwrap
-          ) {
+          if ($l && currentPubkey === $pubkey && currentShouldUnwrap === $shouldUnwrap) {
             subscribeAll($pubkey, getRelayTagValues(getListTags($l)))
           }
         })
@@ -498,27 +462,13 @@ const syncDMs = () => {
     }
   }
 
-  // When pubkey or visibility changes, re-sync
-  const unsubscribePubkey = derived([pubkey, shouldUnwrap, documentVisibility], identity).subscribe(
-    ([$pubkey, $shouldUnwrap, $visibility]) => {
-      currentVisibility = $visibility
-
-      if ($visibility === "hidden") {
-        unsubscribeAll()
-        return
-      }
-
-      syncPubkey($pubkey, $shouldUnwrap)
-    },
-  )
+  const unsubscribePubkey = merged([pubkey, shouldUnwrap]).subscribe(([$pubkey, $shouldUnwrap]) => {
+    syncPubkey($pubkey, $shouldUnwrap)
+  })
 
   // When user messaging relays change, update synchronization
-  const unsubscribeList = derived([userMessagingRelayList, documentVisibility], identity).subscribe(
-    ([$userMessagingRelayList, $visibility]) => {
-      currentVisibility = $visibility
-
-      if ($visibility === "hidden") return
-
+  const unsubscribeList = merged([userMessagingRelayList]).subscribe(
+    ([$userMessagingRelayList]) => {
       syncList($userMessagingRelayList)
     },
   )