test: add Playwright coverage for Slider.vue pressed state

Add e2e tests exercising the slide-start/slide-end events on the
reka-ui Slider component so that the setPressed callback (lines 21-24)
is reached during coverage collection.

- New sliderWidget.spec.ts with two tests: cursor-grabbing assertion
  during pointer hold, and value-change assertion via dragTo.
- New assertBoundingBox() utility that replaces the never-null (!)
  pattern on boundingBox() results with a typed guard that throws a
  descriptive error.
- Fix litegraphUtils.ts dragHorizontal to use assertBoundingBox.

browser_tests/fixtures/utils/assertions.ts

@@ -0,0 +1,18 @@
+import type { Locator } from '@playwright/test'
+
+/**
+ * Retrieve the bounding box of a locator, throwing a descriptive error if
+ * the element has no layout (hidden, detached, or zero-sized).
+ */
+export async function assertBoundingBox(
+  locator: Locator,
+  context?: string
+): Promise<{ x: number; y: number; width: number; height: number }> {
+  const box = await locator.boundingBox()
+  if (!box) {
+    throw new Error(
+      `${context ?? 'Element'} has no bounding box — it may be hidden, detached, or zero-sized`
+    )
+  }
+  return box
+}

browser_tests/fixtures/utils/litegraphUtils.ts

@@ -4,6 +4,7 @@ import type { NodeId } from '@/platform/workflow/validation/schemas/workflowSche
 import { ManageGroupNode } from '@e2e/helpers/manageGroupNode'
 import type { ComfyPage } from '@e2e/fixtures/ComfyPage'
 import type { Position, Size } from '@e2e/fixtures/types'
+import { assertBoundingBox } from '@e2e/fixtures/utils/assertions'
 import { VueNodeFixture } from '@e2e/fixtures/utils/vueNodeFixtures'
 
 export const getMiddlePoint = (pos1: Position, pos2: Position) => {
@@ -241,7 +242,7 @@ class NodeWidgetReference {
   async dragHorizontal(delta: number) {
     const pos = await this.getPosition()
     const canvas = this.node.comfyPage.canvas
-    const canvasPos = (await canvas.boundingBox())!
+    const canvasPos = await assertBoundingBox(canvas, 'Graph canvas')
     await this.node.comfyPage.canvasOps.dragAndDrop(
       {
         x: canvasPos.x + pos.x,

browser_tests/fixtures/utils/pointerEventHelpers.ts

@@ -0,0 +1,62 @@
+import type { Page } from '@playwright/test'
+
+/**
+ * Headless Chromium does not track pointer captures initiated by
+ * synthetic PointerEvents (created via `new PointerEvent()`).
+ * Reka-ui's SliderImpl gates `slideEnd` emission on
+ * `target.hasPointerCapture(pointerId)`, which returns false in this
+ * scenario, preventing the pressed-state from clearing.
+ *
+ * This patch adds a shadow WeakMap tracker so that
+ * `setPointerCapture` / `hasPointerCapture` / `releasePointerCapture`
+ * work correctly for synthetic pointer IDs.
+ *
+ * Call once per page, before any slider interactions.
+ */
+export async function patchPointerCapture(page: Page): Promise<void> {
+  await page.evaluate(() => {
+    const captures = new WeakMap<Element, Set<number>>()
+    const origSet = Element.prototype.setPointerCapture
+    const origRelease = Element.prototype.releasePointerCapture
+    const origHas = Element.prototype.hasPointerCapture
+    Element.prototype.setPointerCapture = function (id: number) {
+      let ids = captures.get(this)
+      if (!ids) captures.set(this, (ids = new Set()))
+      ids.add(id)
+      try {
+        origSet.call(this, id)
+      } catch {
+        /* synthetic pointerId not tracked by browser */
+      }
+    }
+    Element.prototype.hasPointerCapture = function (id: number) {
+      return captures.get(this)?.has(id) ?? origHas.call(this, id)
+    }
+    Element.prototype.releasePointerCapture = function (id: number) {
+      captures.get(this)?.delete(id)
+      try {
+        origRelease.call(this, id)
+      } catch {
+        /* synthetic pointerId not tracked by browser */
+      }
+    }
+  })
+}
+
+export function dispatchPointerEvent({
+  selector,
+  type
+}: {
+  selector: string
+  type: string
+}) {
+  const el = document.querySelector(selector)
+  el?.dispatchEvent(
+    new PointerEvent(type, {
+      bubbles: true,
+      cancelable: true,
+      pointerId: 1,
+      pointerType: 'mouse'
+    })
+  )
+}

browser_tests/tests/vueNodes/widgets/int/sliderWidget.spec.ts

@@ -0,0 +1,49 @@
+import {
+  comfyExpect as expect,
+  comfyPageFixture as test
+} from '@e2e/fixtures/ComfyPage'
+import {
+  patchPointerCapture,
+  dispatchPointerEvent
+} from '@e2e/fixtures/utils/pointerEventHelpers'
+
+const SliderClasses = {
+  pressed: /cursor-grabbing/
+} as const
+
+const SLIDER_NODE_ID = '12'
+const SLIDER_SELECTOR = `[data-node-id="${SLIDER_NODE_ID}"] [data-slot="slider"]`
+
+test.describe('Slider widget', { tag: ['@vue-nodes', '@screenshot'] }, () => {
+  test.beforeEach(async ({ comfyPage }) => {
+    await comfyPage.workflow.loadWorkflow('inputs/simple_slider')
+    await patchPointerCapture(comfyPage.page)
+  })
+
+  test('Track click triggers pressed state on thumb', async ({ comfyPage }) => {
+    const node = comfyPage.vueNodes.getNodeLocator(SLIDER_NODE_ID)
+    const thumb = node.getByRole('slider')
+
+    await comfyPage.page.evaluate(dispatchPointerEvent, {
+      selector: SLIDER_SELECTOR,
+      type: 'pointerdown'
+    })
+    await expect(thumb).toHaveClass(SliderClasses.pressed)
+
+    await comfyPage.page.evaluate(dispatchPointerEvent, {
+      selector: SLIDER_SELECTOR,
+      type: 'pointerup'
+    })
+    await expect(thumb).not.toHaveClass(SliderClasses.pressed)
+  })
+
+  test('Keyboard adjusts slider value', async ({ comfyPage }) => {
+    const node = comfyPage.vueNodes.getNodeLocator(SLIDER_NODE_ID)
+    const thumb = node.getByRole('slider')
+
+    await thumb.focus()
+    await thumb.press('ArrowRight')
+
+    await expect(node).toHaveScreenshot('slider_after_arrow_right.png')
+  })
+})