[Bug] Focus guides: url(#id) paints ignore idPrefix #211

import { expect, it } from 'vitest'
import { scaleLinear } from 'd3-scale'
import { areaY } from './area'
import { crosshair } from './crosshair'
import { motion } from './motion'
import { createChartScene, defineChart } from './scene'

const make = (end: number, top: number) =>
  createChartScene(defineChart({
    marks: [
      areaY([{ x: 0, y: 1 }, { x: 1, y: top }, { x: 2, y: 2 }], { x: 'x', y: 'y', fill: 'url(#fade)' }),
      crosshair({ y: false, stroke: 'url(#fade)' }),
    ],
    scales: { x: { scale: scaleLinear().domain([0, 2]) }, y: { scale: scaleLinear().domain([0, 4]) } },
    gradients: [{ id: 'fade', stops: [
      { offset: 0, color: '#2563eb', opacity: 0.6 }, { offset: end, color: '#2563eb', opacity: 0 }] }],
  }), { width: 320, height: 200 })
const opts = { ariaLabel: 't', idPrefix: 'a' }

it('url(#id) in a focus-guide node is scoped by idPrefix', () => {
  const el = document.createElement('div')
  const surface = motion({ initial: false }).mount(el, () => {})
  const scene = make(1, 3)
  surface.render(scene, opts)
  const p = scene.points[0]!
  surface.paintFocus({ primary: p, group: [p], source: 'pointer', pinned: false })
  const rule = el.querySelector('[data-ts-focus-guide-layer] [data-ts-key$=":x-rule"]')!
  console.log('gradient id:', el.querySelector('linearGradient')?.id, '| guide stroke:', rule.getAttribute('stroke'))
  expect(rule.getAttribute('stroke')).toBe('url(#a-fade)')
})