added test

vue/src/composables/__tests__/viewModeBoot.spec.js

@@ -0,0 +1,72 @@
+// Reproduces the "reload the tab while in article view" boot sequence:
+// module-scope init must pick up the persisted viewMode, and RssFeeds'
+// mount flow (fetchData + sync) must not reset it back to 'list'.
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest'
+import { flushPromises, mount } from '@vue/test-utils'
+
+vi.mock('axios')
+
+class FakeIntersectionObserver {
+  observe() {}
+  unobserve() {}
+  disconnect() {}
+}
+vi.stubGlobal('IntersectionObserver', FakeIntersectionObserver)
+
+describe('viewMode boot persistence', () => {
+  beforeEach(() => {
+    vi.resetModules()
+    localStorage.clear()
+    localStorage.setItem('user-token', 'test-token')
+    localStorage.setItem('user-id', '7')
+  })
+
+  afterEach(() => {
+    localStorage.clear()
+  })
+
+  it('boots into article view when localStorage says so, surviving the mount fetch/sync', async () => {
+    localStorage.setItem('viewMode', 'article')
+
+    const axios = (await import('axios')).default
+    axios.get.mockResolvedValue({
+      data: {
+        feeds: [
+          {
+            title: 'My Feed',
+            items: [
+              { id: 1, title: 'Article one', content: '<p>hi</p>', url: 'https://example.test/1', timestamp: '2026-01-01 10:00:00' },
+            ],
+          },
+        ],
+      },
+    })
+    axios.post.mockResolvedValue({ status: 200 })
+    axios.put.mockResolvedValue({ status: 200 })
+
+    // Import AFTER setting storage — module-scope refs initialize at import.
+    const { useFeeds } = await import('../useFeeds')
+    const { viewMode } = useFeeds()
+    expect(viewMode.value).toBe('article')
+
+    const RssFeeds = (await import('../../components/RssFeeds.vue')).default
+    const wrapper = mount(RssFeeds)
+    await flushPromises()
+
+    expect(viewMode.value).toBe('article')
+    expect(wrapper.find('.article-single').exists()).toBe(true)
+    expect(wrapper.find('#article').exists()).toBe(false)
+
+    wrapper.unmount()
+  })
+
+  it('boots into list view when the key is absent', async () => {
+    const axios = (await import('axios')).default
+    axios.get.mockResolvedValue({ data: { feeds: [] } })
+    axios.post.mockResolvedValue({ status: 200 })
+
+    const { useFeeds } = await import('../useFeeds')
+    const { viewMode } = useFeeds()
+    expect(viewMode.value).toBe('list')
+  })
+})