fix(components): read the GitHub repos cache lazily, per store

packages/components/src/atoms/local-storage-cache.ts

@@ -1,6 +1,6 @@
 import { atom } from 'jotai';
 import type { PersistedMentionRange } from '@/components/mentions/mention-persistence';
-import { atomFamily, atomWithStorage } from 'jotai/utils';
+import { atomFamily, atomWithDefault, atomWithStorage } from 'jotai/utils';
 import type { PastedTextDraft } from '@/lib/pasted-text-draft';
 import {
   type CachedGitHubRepo,
@@ -10,7 +10,13 @@ import {
 
 // ============ GitHub Repos Cache ============
 
-export const allGitHubReposCacheAtom = atom<Record<string, WorkspaceReposCache>>(
+// `atomWithDefault`, not `atom(githubReposCache.readAll())`: a primitive atom's
+// `init` is evaluated once, when this module is imported, and is then shared by
+// every store. Any store created after import would start from that import-time
+// snapshot and silently miss repo lists cached since. Reading lazily gives each
+// store the localStorage contents at its own first read, and keeps the read out
+// of module scope.
+export const allGitHubReposCacheAtom = atomWithDefault<Record<string, WorkspaceReposCache>>(() =>
   githubReposCache.readAll()
 );
 

packages/components/tests/atoms-local-storage-cache.test.ts

@@ -0,0 +1,58 @@
+/** @vitest-environment jsdom */
+
+import { createStore } from 'jotai';
+import { beforeEach, describe, expect, it } from 'vitest';
+
+// Importing this module evaluates the repos-cache atom's default exactly once,
+// against an empty localStorage. Every write below happens after that, which is
+// the whole point: a store built later must not inherit that snapshot.
+import {
+  allGitHubReposCacheAtom,
+  setWorkspaceReposCacheAtom,
+  workspaceReposCacheAtomFamily,
+} from '../src/atoms/local-storage-cache';
+import { githubReposCache, type CachedGitHubRepo } from '../src/lib/local-storage-cache';
+
+const REPOSITORY: CachedGitHubRepo = { fullName: 'LodyAI/Lody', description: null };
+
+beforeEach(() => {
+  localStorage.clear();
+});
+
+describe('allGitHubReposCacheAtom', () => {
+  it('gives a store created after a write the cached repos, not the import-time snapshot', () => {
+    githubReposCache.set('ws-1', { repositories: [REPOSITORY], updatedAt: 1 });
+
+    const laterStore = createStore();
+
+    expect(laterStore.get(allGitHubReposCacheAtom)['ws-1']?.repositories).toEqual([REPOSITORY]);
+    expect(laterStore.get(workspaceReposCacheAtomFamily('ws-1'))).toEqual([REPOSITORY]);
+  });
+
+  it('stays writable through setWorkspaceReposCacheAtom, in localStorage and in the store', () => {
+    const store = createStore();
+
+    store.set(setWorkspaceReposCacheAtom, { workspaceId: 'ws-2', repositories: [REPOSITORY] });
+
+    expect(store.get(workspaceReposCacheAtomFamily('ws-2'))).toEqual([REPOSITORY]);
+    expect(githubReposCache.get('ws-2')?.repositories).toEqual([REPOSITORY]);
+  });
+
+  it('keeps each store independent', () => {
+    const writingStore = createStore();
+    writingStore.set(setWorkspaceReposCacheAtom, {
+      workspaceId: 'ws-3',
+      repositories: [REPOSITORY],
+    });
+
+    // A store built afterwards re-reads localStorage rather than sharing state.
+    const laterStore = createStore();
+    expect(laterStore.get(workspaceReposCacheAtomFamily('ws-3'))).toEqual([REPOSITORY]);
+
+    localStorage.clear();
+    const cleanStore = createStore();
+    expect(cleanStore.get(workspaceReposCacheAtomFamily('ws-3'))).toBeNull();
+    // The store that did the write keeps its own value.
+    expect(writingStore.get(workspaceReposCacheAtomFamily('ws-3'))).toEqual([REPOSITORY]);
+  });
+});