extracted event listeners out of debug components into dedicated files

src/lib/components/connection-status.svelte

@@ -1,40 +1,20 @@
 <script lang="ts">
-  import { onMount } from "svelte";
-  import { commands, events, type ConnectionStatus } from "$lib/bindings";
-
-  let statuses: ConnectionStatus[] = [];
-  let error = "";
-
-  onMount(() => {
-    const unlisten = events.networkStatusChanged.listen((event) => {
-      statuses = event.payload.statuses;
-    });
-
-    commands
-      .listStatuses()
-      .then((current) => {
-        statuses = current;
-      })
-      .catch((err) => {
-        error = String(err);
-      });
-
-    return () => {
-      unlisten.then((stop) => stop());
-    };
-  });
+  import {
+    connectionStatuses,
+    connectionStatusesListenerError,
+  } from "$lib/listeners/connection-status";
 </script>
 
 <section>
   <h1>Connections</h1>
 
-  {#if error}
-    <p aria-live="polite">{error}</p>
-  {:else if statuses.length === 0}
+  {#if $connectionStatusesListenerError}
+    <p aria-live="polite">{$connectionStatusesListenerError}</p>
+  {:else if $connectionStatuses.length === 0}
     <p>No remote connections configured.</p>
   {:else}
     <ul aria-live="polite">
-      {#each statuses as status (status.remoteId)}
+      {#each $connectionStatuses as status (status.remoteId)}
         <li>
           <strong>{status.name ?? status.address}</strong>: {status.state}
           {#if status.name}

src/lib/components/friends-list.svelte

@@ -1,24 +1,9 @@
 <script lang="ts">
-  import { onMount } from "svelte";
-  import { commands, events, type User } from "$lib/bindings";
+  import { commands } from "$lib/bindings";
+  import { friends, friendsListenerError } from "$lib/listeners/friends";
 
-  let friends: User[] = [];
   let error = "";
 
-  onMount(() => {
-    const unlisten = events.friendsChanged.listen((event) => {
-      friends = event.payload.friends;
-    });
-
-    commands.listFriends().catch((err) => {
-      error = String(err);
-    });
-
-    return () => {
-      unlisten.then((stop) => stop());
-    };
-  });
-
   async function createFriend(event: SubmitEvent) {
     const form = event.currentTarget as HTMLFormElement;
     const data = new FormData(form);
@@ -68,15 +53,15 @@
     <button type="submit">Create friend</button>
   </form>
 
-  {#if error}
-    <p>{error}</p>
+  {#if error || $friendsListenerError}
+    <p>{error || $friendsListenerError}</p>
   {/if}
 
-  {#if friends.length === 0}
+  {#if $friends.length === 0}
     <p>No friends saved.</p>
   {:else}
     <ul>
-      {#each friends as friend (friend.id)}
+      {#each $friends as friend (friend.id)}
         <li>
           <span>{friend.displayName} ({friend.id})</span>
           <button type="button" onclick={() => deleteFriend(friend.id)}>Delete</button>

src/lib/components/live-metadata.svelte

@@ -1,28 +1,15 @@
 <script lang="ts">
-  import { onMount } from "svelte";
   import {
-    commands,
-    events,
-    type AppMeta,
-    type CursorPositions,
-  } from "$lib/bindings";
-
-  let localId = "";
-  let cursorPositions: Partial<Record<string, CursorPositions>> = {};
-  let foregroundApps = new Map<string, AppMeta>();
-  let pendingLocalForegroundApp: AppMeta | null = null;
-  let error = "";
-
-  function updateForegroundApp(userId: string, meta: AppMeta) {
-    foregroundApps = new Map(foregroundApps).set(userId, meta);
-  }
+    liveMetadata,
+    liveMetadataListenerError,
+  } from "$lib/listeners/live-metadata";
 
   function liveUserIds() {
     return [
       ...new Set([
-        localId,
-        ...Object.keys(cursorPositions),
-        ...foregroundApps.keys(),
+        $liveMetadata.localId,
+        ...Object.keys($liveMetadata.cursorPositions),
+        ...$liveMetadata.foregroundApps.keys(),
       ]),
     ].filter(Boolean);
   }
@@ -30,69 +17,21 @@
   function compactId(id: string) {
     return id.length > 16 ? `${id.slice(0, 8)}…${id.slice(-6)}` : id;
   }
-
-  onMount(() => {
-    let disposed = false;
-    let stopListeners: (() => void)[] = [];
-
-    async function initialize() {
-      const listeners = await Promise.all([
-        events.cursorPositionChanged.listen((event) => {
-          if (!disposed) cursorPositions = event.payload.positions;
-        }),
-        events.foregroundAppChanged.listen((event) => {
-          if (disposed) return;
-          if (localId) {
-            updateForegroundApp(localId, event.payload.meta);
-          } else {
-            pendingLocalForegroundApp = event.payload.meta;
-          }
-        }),
-        events.friendForegroundAppChanged.listen((event) => {
-          if (!disposed) {
-            updateForegroundApp(event.payload.friendId, event.payload.meta);
-          }
-        }),
-      ]);
-
-      if (disposed) {
-        listeners.forEach((stop) => stop());
-        return;
-      }
-      stopListeners = listeners;
-
-      localId = await commands.getPublicKey();
-      if (disposed) return;
-      if (pendingLocalForegroundApp) {
-        updateForegroundApp(localId, pendingLocalForegroundApp);
-        pendingLocalForegroundApp = null;
-      }
-    }
-
-    initialize().catch((err) => {
-      if (!disposed) error = String(err);
-    });
-
-    return () => {
-      disposed = true;
-      stopListeners.forEach((stop) => stop());
-    };
-  });
 </script>
 
 <section>
   <h1>Live metadata</h1>
 
-  {#if error}
-    <p>{error}</p>
+  {#if $liveMetadataListenerError}
+    <p>{$liveMetadataListenerError}</p>
   {:else if liveUserIds().length === 0}
     <p>Waiting for live metadata...</p>
   {:else}
     {#each liveUserIds() as userId (userId)}
-      {@const cursor = cursorPositions[userId]}
-      {@const foregroundApp = foregroundApps.get(userId)}
+      {@const cursor = $liveMetadata.cursorPositions[userId]}
+      {@const foregroundApp = $liveMetadata.foregroundApps.get(userId)}
       <article>
-        <h2>{userId === localId ? "Local user" : "Remote user"}</h2>
+        <h2>{userId === $liveMetadata.localId ? "Local user" : "Remote user"}</h2>
         <p title={userId}>ID: {compactId(userId)}</p>
 
         <h3>Cursor</h3>

src/lib/components/profile.svelte

@@ -1,39 +1,11 @@
 <script lang="ts">
-  import { onMount } from "svelte";
-  import { commands, events, type User } from "$lib/bindings";
+  import { commands } from "$lib/bindings";
+  import { profile, profileListenerError } from "$lib/listeners/profile";
 
-  let profile: User | null = null;
   let displayName = "";
   let error = "";
 
-  onMount(() => {
-    let stop: (() => void) | undefined;
-    let disposed = false;
-
-    async function initialize() {
-      const unlisten = await events.profileChanged.listen((event) => {
-        profile = event.payload.profile;
-        displayName = event.payload.profile.displayName;
-      });
-
-      if (disposed) {
-        unlisten();
-        return;
-      }
-
-      stop = unlisten;
-      await commands.getProfile();
-    }
-
-    initialize().catch((err) => {
-      error = String(err);
-    });
-
-    return () => {
-      disposed = true;
-      stop?.();
-    };
-  });
+  $: displayName = $profile?.displayName ?? "";
 
   async function updateProfile(event: SubmitEvent) {
     event.preventDefault();
@@ -50,8 +22,8 @@
 <section>
   <h1>Profile</h1>
 
-  {#if profile}
-    <p>Public key: {profile.id}</p>
+  {#if $profile}
+    <p>Public key: {$profile.id}</p>
   {:else}
     <p>Loading profile...</p>
   {/if}
@@ -64,7 +36,7 @@
     <button type="submit">Save profile</button>
   </form>
 
-  {#if error}
-    <p>{error}</p>
+  {#if error || $profileListenerError}
+    <p>{error || $profileListenerError}</p>
   {/if}
 </section>

src/lib/components/remotes-list.svelte

@@ -1,25 +1,10 @@
 <script lang="ts">
-  import { onMount } from "svelte";
-  import { commands, events, type Remote, type RemoteInput } from "$lib/bindings";
+  import { commands, type RemoteInput } from "$lib/bindings";
+  import { remotes, remotesListenerError } from "$lib/listeners/remotes";
 
-  let remotes: Remote[] = [];
   let editingId: string | null = null;
   let error = "";
 
-  onMount(() => {
-    const unlisten = events.remotesChanged.listen((event) => {
-      remotes = event.payload.remotes;
-    });
-
-    commands.listRemotes().catch((err) => {
-      error = String(err);
-    });
-
-    return () => {
-      unlisten.then((stop) => stop());
-    };
-  });
-
   function remoteInput(form: HTMLFormElement): RemoteInput {
     const data = new FormData(form);
     const name = String(data.get("name") ?? "").trim();
@@ -98,15 +83,15 @@
     <button type="submit">Create remote</button>
   </form>
 
-  {#if error}
-    <p aria-live="polite">{error}</p>
+  {#if error || $remotesListenerError}
+    <p aria-live="polite">{error || $remotesListenerError}</p>
   {/if}
 
-  {#if remotes.length === 0}
+  {#if $remotes.length === 0}
     <p>No remotes saved.</p>
   {:else}
     <ul>
-      {#each remotes as remote (remote.id)}
+      {#each $remotes as remote (remote.id)}
         <li>
           {#if editingId === remote.id}
             <form onsubmit={(event) => updateRemote(event, remote.id)}>

src/lib/listeners/connection-status.ts

@@ -0,0 +1,19 @@
+import { writable } from "svelte/store";
+import { commands, events, type ConnectionStatus } from "$lib/bindings";
+
+export const connectionStatuses = writable<ConnectionStatus[]>([]);
+export const connectionStatusesListenerError = writable("");
+
+export async function initConnectionStatusesListener() {
+  const unlisten = await events.networkStatusChanged.listen((event) => {
+    connectionStatuses.set(event.payload.statuses);
+  });
+
+  try {
+    connectionStatuses.set(await commands.listStatuses());
+  } catch (error) {
+    connectionStatusesListenerError.set(String(error));
+  }
+
+  return unlisten;
+}

src/lib/listeners/friends.ts

@@ -0,0 +1,19 @@
+import { writable } from "svelte/store";
+import { commands, events, type User } from "$lib/bindings";
+
+export const friends = writable<User[]>([]);
+export const friendsListenerError = writable("");
+
+export async function initFriendsListener() {
+  const unlisten = await events.friendsChanged.listen((event) => {
+    friends.set(event.payload.friends);
+  });
+
+  try {
+    friends.set(await commands.listFriends());
+  } catch (error) {
+    friendsListenerError.set(String(error));
+  }
+
+  return unlisten;
+}

src/lib/listeners/index.ts

@@ -0,0 +1,43 @@
+import { initConnectionStatusesListener } from "./connection-status";
+import { initFriendsListener } from "./friends";
+import { initLiveMetadataListeners } from "./live-metadata";
+import { initProfileListener } from "./profile";
+import { initRemotesListener } from "./remotes";
+
+type Unlisten = () => void;
+
+export function initAppListeners(): Unlisten {
+  let disposed = false;
+  let unlisteners: Unlisten[] = [];
+
+  Promise.allSettled([
+    initFriendsListener(),
+    initRemotesListener(),
+    initProfileListener(),
+    initConnectionStatusesListener(),
+    initLiveMetadataListeners(),
+  ])
+    .then((results) => {
+      const listeners = results.flatMap((result) =>
+        result.status === "fulfilled" ? [result.value] : [],
+      );
+
+      results.forEach((result) => {
+        if (result.status === "rejected") {
+          console.error("failed to initialize app listener", result.reason);
+        }
+      });
+
+      if (disposed) {
+        listeners.forEach((unlisten) => unlisten());
+      } else {
+        unlisteners = listeners;
+      }
+    });
+
+  return () => {
+    disposed = true;
+    unlisteners.forEach((unlisten) => unlisten());
+    unlisteners = [];
+  };
+}

src/lib/listeners/live-metadata.ts

@@ -0,0 +1,65 @@
+import { writable } from "svelte/store";
+import {
+  commands,
+  events,
+  type AppMeta,
+  type CursorPositions,
+} from "$lib/bindings";
+
+export type LiveMetadata = {
+  localId: string;
+  cursorPositions: Partial<Record<string, CursorPositions>>;
+  foregroundApps: Map<string, AppMeta>;
+};
+
+export const liveMetadata = writable<LiveMetadata>({
+  localId: "",
+  cursorPositions: {},
+  foregroundApps: new Map(),
+});
+export const liveMetadataListenerError = writable("");
+
+export async function initLiveMetadataListeners() {
+  let localId = "";
+  let pendingLocalForegroundApp: AppMeta | null = null;
+
+  const updateForegroundApp = (userId: string, meta: AppMeta) => {
+    liveMetadata.update((current) => ({
+      ...current,
+      foregroundApps: new Map(current.foregroundApps).set(userId, meta),
+    }));
+  };
+
+  const unlisteners = await Promise.all([
+    events.cursorPositionChanged.listen((event) => {
+      liveMetadata.update((current) => ({
+        ...current,
+        cursorPositions: event.payload.positions,
+      }));
+    }),
+    events.foregroundAppChanged.listen((event) => {
+      if (localId) {
+        updateForegroundApp(localId, event.payload.meta);
+      } else {
+        pendingLocalForegroundApp = event.payload.meta;
+      }
+    }),
+    events.friendForegroundAppChanged.listen((event) => {
+      updateForegroundApp(event.payload.friendId, event.payload.meta);
+    }),
+  ]);
+
+  try {
+    localId = await commands.getPublicKey();
+    liveMetadata.update((current) => ({ ...current, localId }));
+
+    if (pendingLocalForegroundApp) {
+      updateForegroundApp(localId, pendingLocalForegroundApp);
+      pendingLocalForegroundApp = null;
+    }
+  } catch (error) {
+    liveMetadataListenerError.set(String(error));
+  }
+
+  return () => unlisteners.forEach((unlisten) => unlisten());
+}

src/lib/listeners/profile.ts

@@ -0,0 +1,19 @@
+import { writable } from "svelte/store";
+import { commands, events, type User } from "$lib/bindings";
+
+export const profile = writable<User | null>(null);
+export const profileListenerError = writable("");
+
+export async function initProfileListener() {
+  const unlisten = await events.profileChanged.listen((event) => {
+    profile.set(event.payload.profile);
+  });
+
+  try {
+    profile.set(await commands.getProfile());
+  } catch (error) {
+    profileListenerError.set(String(error));
+  }
+
+  return unlisten;
+}

src/lib/listeners/remotes.ts

@@ -0,0 +1,19 @@
+import { writable } from "svelte/store";
+import { commands, events, type Remote } from "$lib/bindings";
+
+export const remotes = writable<Remote[]>([]);
+export const remotesListenerError = writable("");
+
+export async function initRemotesListener() {
+  const unlisten = await events.remotesChanged.listen((event) => {
+    remotes.set(event.payload.remotes);
+  });
+
+  try {
+    remotes.set(await commands.listRemotes());
+  } catch (error) {
+    remotesListenerError.set(String(error));
+  }
+
+  return unlisten;
+}

src/routes/+layout.svelte

@@ -1,8 +1,13 @@
 <script>
   import { browser } from "$app/environment";
+  import { onMount } from "svelte";
+  import { initAppListeners } from "$lib/listeners";
   import "../app.css";
 
   let { children } = $props();
+
+  onMount(initAppListeners);
+
   if (browser) {
     document.addEventListener("contextmenu", (e) => {
       e.preventDefault();