Fix shadow DOM - drag-and-drop text throws error

[Hentuloo]

Fix an error when dragging and dropping text in a Slate editor inside a Shadow DOM, resulting in:
Error: Cannot resolve a Slate point from DOM point: [object HTMLDivElement],0.

Issue
Fixes: [Link to issue]

Context

The existing support for the third parameter options in caretPositionFromPoint is limited. To address this problem, additional logic was implemented to find the nearest character next to the cursor at the time of the drop event.

Checks

• The new code matches the existing patterns and styles.
• The tests pass with yarn test.
• The linter passes with yarn lint. (Fix errors with yarn fix.)
• The relevant examples still work. (Run examples with yarn start.)
• You've added a changeset if changing functionality. (Add one with yarn changeset add.)

[changeset-bot]

⚠️ No Changeset found

Latest commit: 1b53ae2

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[Hentuloo]

I also tried it in a slightly different way, but unfortunately, it didn't work with Firefox.

import { test, expect } from '@playwright/test'

test.describe('shadow-dom example', () => {
  test.beforeEach(async ({ page }) => {
    await page.goto('http://localhost:3000/examples/shadow-dom')
  })

  test('drag and drop text above the textbox', async ({ page }) => {
    const outerShadow = page.locator('[data-cy="outer-shadow-root"]')
    const innerShadow = outerShadow.locator('> div')

    // Locate the textbox within the shadow DOM
    const textbox = innerShadow.getByRole('textbox')
    await textbox.fill('test1 test2')

    await page.waitForTimeout(1500)
    // Locate the span element that contains "test1 test2"
    const textSpan = innerShadow.locator('span[data-slate-string="true"]')

    // Wait for the content to be available
    await textSpan.waitFor()
    await textSpan.hover()

    await page.waitForTimeout(100)

    // Locate the text nodes for "test1" and "test2"
    const test1 = textSpan.locator('text=test1')

    const test1BoundingBox = await test1.boundingBox()
    console.log('test1BoundingBox:', test1BoundingBox)
    // Check if the bounding box was retrieved successfully
    if (test1BoundingBox) {
      // Drag "test1" and drop it after "test2"
      await page.mouse.click(
        test1BoundingBox.x,
        test1BoundingBox.y + test1BoundingBox.height / 2,
        { force: true }
      )

      await page.mouse.down()

      await page.waitForTimeout(100)

      await page.waitForTimeout(100)
      await page.mouse.move(
        test1BoundingBox.x + test1BoundingBox.width / 2,
        test1BoundingBox.y + test1BoundingBox.height / 2
      )
      await page.mouse.up()

      await page.waitForTimeout(100)

      await page.mouse.move(
        test1BoundingBox.x,
        test1BoundingBox.y + test1BoundingBox.height / 2
      )
      await page.mouse.down()

      await page.waitForTimeout(100)
      await page.mouse.move(
        test1BoundingBox.x + test1BoundingBox.width,
        test1BoundingBox.y + test1BoundingBox.height / 2
      )
      await page.mouse.up()

      await page.waitForTimeout(100)

      await expect(textbox).toHaveText('test2test1')
    }
  })
})```