fix race condition in isfollowing

src/lib/components/BotonSeguir.svelte

@@ -11,7 +11,7 @@
 	import { seguirUsuario } from '@/hooks/seguirUsuario';
 	import type { Post } from '../../types';
 	import CardError from './CardError.svelte';
-	import { cacheSeguidos } from '@/stores/cacheSeguidos.svelte';
+	import { cacheSeguidos } from '@/stores/cacheSeguidos.js';
 
 	let {
 		post,
@@ -41,16 +41,13 @@
 	});
 
 	async function cargarSeguido() {
-		let a = cacheSeguidos.get(post.authorId);
+		seguido = await cacheSeguidos.getOrFetch(
-		if (a === undefined) {
+			post.authorId,
+			async () => {
 				const seguidoStatus = await esSeguido(post as Post);
-			if (seguidoStatus) {
+				return seguidoStatus?.isFollowing || false;
-				cacheSeguidos.set(post.authorId, seguidoStatus.isFollowing || false);
-				seguido = seguidoStatus.isFollowing || false;
 			}
-			return;
+		);
-		}
-		seguido = a;
 	}
 
 	let mensajeError: string | null = $state(null);

src/lib/hooks/logout.ts

@@ -1,5 +1,5 @@
 import { goto } from '$app/navigation';
-import { cacheSeguidos } from '@/stores/cacheSeguidos.svelte';
+import { cacheSeguidos } from '@/stores/cacheSeguidos';
 import { apiBase } from '@/stores/url';
 import { sesionStore } from '@/stores/usuario';
 import { get } from 'svelte/store';

src/lib/stores/cacheSeguidos.js

@@ -0,0 +1,134 @@
+import { browser } from '$app/environment';
+import { writable } from 'svelte/store';
+
+class FollowCache {
+	constructor() {
+		if (browser) {
+			this.loadFromStorage();
+		}
+	}
+
+	/** @type {Map<string, boolean | Promise<boolean>>} */
+	#cache = new Map();
+
+	/** @type {import('svelte/store').Writable<Map<string, boolean>>} */
+	store = writable(new Map());
+
+	/** @param {string} userId */
+	get(userId) {
+		const value = this.#cache.get(userId);
+		return value instanceof Promise ? undefined : value;
+	}
+
+  	/** @param {string} userId */
+	has(userId) {
+		return this.#cache.has(userId);
+	}
+
+	/**
+	 * @param {string} userId
+	 * @param {() => Promise<boolean>} fetchFn
+	 */
+	async getOrFetch(userId, fetchFn) {
+		const existing = this.#cache.get(userId);
+
+		if (existing !== undefined) {
+			if (existing instanceof Promise) {
+				return existing;
+			}
+			return existing;
+		}
+
+		const promise = fetchFn()
+			.then((result) => {
+				this.#setFinal(userId, result);
+				return result;
+			})
+			.catch((err) => {
+				this.#cache.delete(userId);
+				this.#updateStore();
+				throw err;
+			});
+
+		this.#cache.set(userId, promise);
+		this.#updateStore();
+
+		return promise;
+	}
+
+	/**
+	 * @param {string} userId
+	 * @param {boolean} isFollowed
+	 */
+	set(userId, isFollowed) {
+		this.#setFinal(userId, isFollowed);
+	}
+
+	/**
+	 * @param {string} userId
+	 * @param {boolean} value
+	 */
+	#setFinal(userId, value) {
+		this.#cache.set(userId, value);
+		this.#updateStore();
+		this.saveToStorage();
+
+		if (browser) {
+			window.dispatchEvent(
+				new CustomEvent('followCacheUpdated', {
+					detail: { userId, isFollowed: value }
+				})
+			);
+		}
+	}
+
+	#updateStore() {
+		const filtered = Array.from(this.#cache.entries())
+			.filter(([_, v]) => typeof v === 'boolean');
+
+		this.store.set(
+			/** @type {Map<string, boolean>} */
+			(new Map(filtered))
+		);
+	}
+
+	/** @param {string} userId */
+	delete(userId) {
+		this.#cache.delete(userId);
+		this.#updateStore();
+		this.saveToStorage();
+	}
+
+	clear() {
+		this.#cache.clear();
+		this.store.set(new Map());
+		this.saveToStorage();
+	}
+
+	saveToStorage() {
+		if (!browser) return;
+		const filtered = Array.from(this.#cache.entries())
+			.filter(([_, v]) => typeof v === 'boolean');
+
+		const data = Object.fromEntries(filtered);
+		sessionStorage.setItem('follow-cache', JSON.stringify(data));
+	}
+
+	loadFromStorage() {
+		if (!browser) return;
+
+		try {
+			const stored = sessionStorage.getItem('follow-cache');
+			if (!stored) return;
+			const data = JSON.parse(stored);
+
+			this.#cache = new Map(Object.entries(data));
+			this.#updateStore();
+
+		} catch (err) {
+			console.error('Error cargando follow-cache:', err);
+		}
+	}
+}
+
+export const cacheSeguidos = new FollowCache();

src/lib/stores/cacheSeguidos.svelte.js

@@ -1,105 +0,0 @@
-import { browser } from '$app/environment';
-import { writable } from 'svelte/store';
-
-class FollowCache {
-	constructor() {
-		if (browser) {
-			this.loadFromStorage();
-		}
-	}
-
-	/** @type {Map<string, boolean>} */
-	#cache = new Map();
-
-	/** @type {import('svelte/store').Writable<Map<string, boolean>>} */
-	store = writable(this.#cache);
-
-	/**
-	 * @param {string} userId
-	 * @returns {boolean | undefined}
-	 */
-	get(userId) {
-		return this.#cache.get(userId);
-	}
-
-	/**
-	 * @param {string} userId
-	 * @param {boolean} isFollowed
-	 */
-	set(userId, isFollowed) {
-		this.#cache.set(userId, isFollowed);
-		this.store.set(this.#cache);
-		this.saveToStorage();
-
-		if (browser) {
-			window.dispatchEvent(
-				new CustomEvent('followCacheUpdated', {
-					detail: { userId, isFollowed }
-				})
-			);
-		}
-	}
-
-	/**
-	 * @param {string} userId
-	 * @returns {boolean}
-	 */
-	has(userId) {
-		return this.#cache.has(userId);
-	}
-
-	/**
-	 * @param {string} userId
-	 */
-	delete(userId) {
-		this.#cache.delete(userId);
-		this.store.set(this.#cache);
-		this.saveToStorage();
-
-		if (browser) {
-			window.dispatchEvent(
-				new CustomEvent('followCacheUpdated', {
-					detail: { userId, isFollowed: false }
-				})
-			);
-		}
-	}
-
-	clear() {
-		this.#cache.clear();
-		this.store.set(this.#cache);
-		this.saveToStorage();
-
-		if (browser) {
-			window.dispatchEvent(
-				new CustomEvent('followCacheUpdated', {
-					detail: { clearAll: true }
-				})
-			);
-		}
-	}
-
-	saveToStorage() {
-		if (browser) {
-			const data = Object.fromEntries(this.#cache);
-			sessionStorage.setItem('follow-cache', JSON.stringify(data));
-		}
-	}
-
-	loadFromStorage() {
-		if (browser) {
-			try {
-				const stored = sessionStorage.getItem('follow-cache');
-				if (stored) {
-					const data = JSON.parse(stored);
-					this.#cache = new Map(Object.entries(data));
-					this.store.set(this.#cache);
-				}
-			} catch (error) {
-				console.error('Error cargando desde sesion:', error);
-			}
-		}
-	}
-}
-
-export const cacheSeguidos = new FollowCache();