test(vue3): add VirtualList coverage

Signed-off-by: Vitor Mattos <1079143+vitormattos@users.noreply.github.com>

Author: vitormattos

src/tests/views/FilesList/VirtualList.spec.ts

@@ -0,0 +1,121 @@
+/**
+ * SPDX-FileCopyrightText: 2026 LibreCode coop and contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import { mount } from '@vue/test-utils'
+import { markRaw } from 'vue'
+
+import VirtualList from '../../../views/FilesList/VirtualList.vue'
+
+const filesStoreMock = {
+	loading: false,
+	getAllFiles: vi.fn(),
+	filesSorted: vi.fn(() => [] as Array<{ id: number, name: string }>),
+}
+
+const userConfigStoreMock = {
+	files_list_grid_view: false,
+}
+
+const subscribeMock = vi.fn()
+const unsubscribeMock = vi.fn()
+
+class IntersectionObserverMock {
+	observe = vi.fn()
+	disconnect = vi.fn()
+
+	constructor(public callback: IntersectionObserverCallback) {}
+}
+
+vi.mock('@nextcloud/l10n', () => ({
+	t: vi.fn((_app: string, text: string) => text),
+	translate: vi.fn((_app: string, text: string) => text),
+	translatePlural: vi.fn((_app: string, singular: string, plural: string, count: number) => (count === 1 ? singular : plural)),
+	n: vi.fn((_app: string, singular: string, plural: string, count: number) => (count === 1 ? singular : plural)),
+	getLanguage: vi.fn(() => 'en'),
+	getLocale: vi.fn(() => 'en'),
+	isRTL: vi.fn(() => false),
+}))
+
+vi.mock('debounce', () => ({
+	default: vi.fn((fn: (...args: unknown[]) => unknown) => fn),
+}))
+
+vi.mock('@nextcloud/event-bus', () => ({
+	subscribe: vi.fn((...args: unknown[]) => subscribeMock(...args)),
+	unsubscribe: vi.fn((...args: unknown[]) => unsubscribeMock(...args)),
+}))
+
+vi.mock('../../../store/files.js', () => ({
+	useFilesStore: vi.fn(() => filesStoreMock),
+}))
+
+vi.mock('../../../store/userconfig.js', () => ({
+	useUserConfigStore: vi.fn(() => userConfigStoreMock),
+}))
+
+describe('VirtualList.vue', () => {
+	beforeEach(() => {
+		vi.clearAllMocks()
+		filesStoreMock.loading = false
+		filesStoreMock.getAllFiles.mockReset()
+		filesStoreMock.filesSorted.mockReturnValue([])
+		userConfigStoreMock.files_list_grid_view = false
+		globalThis.IntersectionObserver = IntersectionObserverMock as unknown as typeof IntersectionObserver
+	})
+
+	function createWrapper() {
+		return mount(VirtualList, {
+			props: {
+				dataComponent: markRaw({
+					name: 'RowComponent',
+					props: ['source', 'loading'],
+					template: '<tr class="row-component"><td>{{ source.name }}</td></tr>',
+				}),
+				loading: false,
+				caption: 'Files table',
+			},
+			global: {
+				stubs: {
+					transition: false,
+				},
+			},
+			slots: {
+				empty: '<div class="empty-slot">Nothing here</div>',
+				header: '<tr class="header-slot"><th>Name</th></tr>',
+				footer: '<tr class="footer-slot"><td>Footer</td></tr>',
+			},
+		})
+	}
+
+	it('renders the empty slot when there are no files', () => {
+		const wrapper = createWrapper()
+
+		expect(wrapper.find('.files-list__empty').exists()).toBe(true)
+		expect(wrapper.find('.empty-slot').text()).toBe('Nothing here')
+		expect(wrapper.find('.files-list__table').classes()).toContain('files-list__table--hidden')
+	})
+
+	it('renders rows and grid body class when files exist in grid mode', () => {
+		filesStoreMock.filesSorted.mockReturnValue([
+			{ id: 1, name: 'first.pdf' },
+			{ id: 2, name: 'second.pdf' },
+		])
+		userConfigStoreMock.files_list_grid_view = true
+		const wrapper = createWrapper()
+
+		expect(wrapper.findAll('.row-component')).toHaveLength(2)
+		expect(wrapper.find('.files-list').classes()).toContain('files-list--grid')
+		expect(wrapper.find('.files-list__tbody').classes()).toContain('files-list__tbody--grid')
+	})
+
+	it('loads more files immediately when not currently loading', () => {
+		const wrapper = createWrapper()
+
+		wrapper.vm.getFilesIfNotLoading()
+
+		expect(filesStoreMock.getAllFiles).toHaveBeenCalledTimes(1)
+	})
+})