[Bug]: 1.63 regression - Locator.highlight does not work with custom selector engines that rely on global variables #42849

import { test as base } from '@playwright/test'

declare global {
    interface Window {
        selectorEngineEnabled?: true | undefined
    }
}

export const test = base.extend<{}, { selectorRegistration: void }>({
    selectorRegistration: [
        async ({ playwright }, use) => {
            await playwright.selectors.register('tag', () => ({
                queryAll: (root: Element | Document, selector: string) => {
                    if (typeof window.selectorEngineEnabled === 'boolean') {
                        return Array.from(root.querySelectorAll(selector))
                    }
                    return []
                },
                query: (root: Element | Document, selector: string) => {
                    if (typeof window.selectorEngineEnabled === 'boolean') {
                        return root.querySelector(selector)
                    }
                    return []
                },
            }))
            await use()
        },
        { scope: 'worker', auto: true },
    ],
})

test('selector engine test', async ({ page }) => {
    await page.evaluate(() => (window.selectorEngineEnabled = true))
    await page.setContent('<button>asdf</button>')
    const button = page.locator('tag=button')
    await button.highlight() // doesn't work
    await button.click() // does work
})