text: 
  import assert from 'assert'
  
  export default function (state) {
    const { startText, selection } = state
    const props = {
      anchorKey: startText.key,
      anchorOffset: 0,
      focusKey: startText.key,
      focusOffset: startText.length,
    }
  
    const sel = selection.merge(props)
    const next = state
      .transform()
      .select(props)
      .apply()
  
    assert.deepEqual(
      next.selection.toJS(),
      sel.toJS()
    )
  }
  