test: migrate 132 test files from @vue/test-utils to @testing-library/vue (#10965)

## Summary

Migrate 132 test files from `@vue/test-utils` (VTU) to
`@testing-library/vue` (VTL) with `@testing-library/user-event`,
adopting user-centric behavioral testing patterns across the codebase.

## Changes

- **What**: Systematic migration of component/unit tests from VTU's
`mount`/`wrapper` API to VTL's `render`/`screen`/`userEvent` API across
132 files in `src/`
- **Breaking**: None — test-only changes, no production code affected

### Migration breakdown

| Batch | Files | Description |
|-------|-------|-------------|
| 1 | 19 | Simple render/assert tests |
| 2A | 16 | Interactive tests with user events |
| 2B-1 | 14 | Interactive tests (continued) |
| 2B-2 | 32 | Interactive tests (continued) |
| 3A–3E | 51 | Complex tests (stores, composables, heavy mocking) |
| Lint fix | 7 | `await` on `fireEvent` calls for `no-floating-promises`
|
| Review fixes | 15 | Address CodeRabbit feedback (3 rounds) |

### Review feedback addressed

- Removed class-based assertions (`text-ellipsis`, `pr-3`, `.pi-save`,
`.skeleton`, `.bg-black\/15`, Tailwind utilities) in favor of
behavioral/accessible queries
- Added null guards before `querySelector` casts
- Added `expect(roots).toHaveLength(N)` guards before indexed NodeList
access
- Wrapped fake timer tests in `try/finally` for guaranteed cleanup
- Split double-render tests into focused single-render tests
- Replaced CSS class selectors with
`screen.getByText`/`screen.getByRole` queries
- Updated stubs to use semantic `role`/`aria-label` instead of CSS
classes
- Consolidated redundant edge-case tests
- Removed manual `document.body.appendChild` in favor of VTL container
management
- Used distinct mock return values to verify command wiring

### VTU holdouts (2 files)

These files intentionally retain `@vue/test-utils` because their
components use `<script setup>` without `defineExpose`, making internal
computed properties and methods inaccessible via VTL:

1. **`NodeWidgets.test.ts`** — partial VTU for `vm.processedWidgets`
2. **`WidgetSelectDropdown.test.ts`** — full VTU for heavy
`wrapper.vm.*` access

## Follow-up

Deferred items (`ComponentProps` typing, camelCase listener props)
tracked in #10966.

## Review Focus

- Test correctness: all migrated tests preserve original behavioral
coverage
- VTL idioms: proper use of `screen` queries, `userEvent`, and
accessibility-based selectors
- The 2 VTU holdout files are intentional, not oversights

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-10965-test-migrate-132-test-files-from-vue-test-utils-to-testing-library-vue-33c6d73d36508199a6a7e513cf5d8296)
by [Unito](https://www.unito.io)

---------

Co-authored-by: Amp <amp@ampcode.com>
Co-authored-by: Christian Byrne <cbyrne@comfy.org>

src/components/common/TextTickerMultiLine.test.ts

@@ -1,8 +1,7 @@
-import { mount } from '@vue/test-utils'
+import { render, screen } from '@testing-library/vue'
 import { nextTick } from 'vue'
 import { afterEach, describe, expect, it, vi } from 'vitest'
 
-import MarqueeLine from './MarqueeLine.vue'
 import TextTickerMultiLine from './TextTickerMultiLine.vue'
 
 type Callback = () => void
@@ -41,23 +40,38 @@ function mockElementSize(
 }
 
 describe(TextTickerMultiLine, () => {
-  let wrapper: ReturnType<typeof mount>
+  let unmountFn: () => void
 
   afterEach(() => {
-    wrapper?.unmount()
+    unmountFn?.()
     resizeCallbacks.length = 0
     mutationCallbacks.length = 0
   })
 
-  function mountComponent(text: string) {
-    wrapper = mount(TextTickerMultiLine, {
+  function renderComponent(text: string) {
+    const result = render(TextTickerMultiLine, {
       slots: { default: text }
     })
-    return wrapper
+    unmountFn = result.unmount
+    return {
+      ...result,
+      container: result.container as HTMLElement
+    }
   }
 
-  function getMeasureEl(): HTMLElement {
-    return wrapper.find('[aria-hidden="true"]').element as HTMLElement
+  function getMeasureEl(container: HTMLElement): HTMLElement {
+    // eslint-disable-next-line testing-library/no-node-access
+    return container.querySelector('[aria-hidden="true"]') as HTMLElement
+  }
+
+  function getVisibleLines(container: HTMLElement): HTMLElement[] {
+    /* eslint-disable testing-library/no-node-access */
+    return Array.from(
+      container.querySelectorAll<HTMLElement>(
+        'div.overflow-hidden:not([aria-hidden])'
+      )
+    )
+    /* eslint-enable testing-library/no-node-access */
   }
 
   async function triggerSplitLines() {
@@ -66,40 +80,42 @@ describe(TextTickerMultiLine, () => {
   }
 
   it('renders slot content', () => {
-    mountComponent('Load Checkpoint')
-    expect(wrapper.text()).toContain('Load Checkpoint')
+    renderComponent('Load Checkpoint')
+    expect(
+      screen.getAllByText('Load Checkpoint').length
+    ).toBeGreaterThanOrEqual(1)
   })
 
-  it('renders a single MarqueeLine when text fits', async () => {
-    mountComponent('Short')
-    mockElementSize(getMeasureEl(), 200, 100)
+  it('renders a single line when text fits', async () => {
+    const { container } = renderComponent('Short')
+    mockElementSize(getMeasureEl(container), 200, 100)
     await triggerSplitLines()
 
-    expect(wrapper.findAllComponents(MarqueeLine)).toHaveLength(1)
+    expect(getVisibleLines(container)).toHaveLength(1)
   })
 
-  it('renders two MarqueeLines when text overflows', async () => {
-    mountComponent('Load Checkpoint Loader Simple')
-    mockElementSize(getMeasureEl(), 100, 300)
+  it('renders two lines when text overflows', async () => {
+    const { container } = renderComponent('Load Checkpoint Loader Simple')
+    mockElementSize(getMeasureEl(container), 100, 300)
     await triggerSplitLines()
 
-    expect(wrapper.findAllComponents(MarqueeLine)).toHaveLength(2)
+    expect(getVisibleLines(container)).toHaveLength(2)
   })
 
   it('splits text at word boundary when overflowing', async () => {
-    mountComponent('Load Checkpoint Loader')
-    mockElementSize(getMeasureEl(), 100, 200)
+    const { container } = renderComponent('Load Checkpoint Loader')
+    mockElementSize(getMeasureEl(container), 100, 200)
     await triggerSplitLines()
 
-    const lines = wrapper.findAllComponents(MarqueeLine)
-    expect(lines[0].text()).toBe('Load')
-    expect(lines[1].text()).toBe('Checkpoint Loader')
+    const lines = getVisibleLines(container)
+    expect(lines[0].textContent).toBe('Load')
+    expect(lines[1].textContent).toBe('Checkpoint Loader')
   })
 
   it('has hidden measurement element with aria-hidden', () => {
-    mountComponent('Test')
-    const measureEl = wrapper.find('[aria-hidden="true"]')
-    expect(measureEl.exists()).toBe(true)
-    expect(measureEl.classes()).toContain('invisible')
+    const { container } = renderComponent('Test')
+    const measureEl = getMeasureEl(container)
+    expect(measureEl).toBeInTheDocument()
+    expect(measureEl).toHaveClass('invisible')
   })
 })