Unexpect behavior when text node with single character

[Benbinbin]

record.mp4

because the property $pos.textOffset will be zero when the positions that point between nodes, it causes the unexpect behavior(show in the video) when text node with single character

maybe we can change the conditional as follow to tell if the position point into the first charater of the textNode and press ArrowLeft

const nodeBefore = $pos.nodeBefore;

if (event.key === 'ArrowLeft' && nodeBefore.isText && nodeBefore.nodeSize === 1) {
  // ...
}