Strange Hydration action

[slava-lu]

Describe the bug

When using Broadcast Channel API with 'channel.postMessage()' function and running some action upon receiving the message an unnecessary Hydration action is fired. in 8.0 it overwritten my store. In 8.1 seems it does not but still makes me uneasy.

My app uses only 'getInitialProps' so I do not expect any Hydration actions apart from the first action on the client.

To Reproduce

Difficult to reproduce as you need to have some setup with Broadcast Channel API

Expected behavior

I expect that no Hydration action is triggered if there is no SSR.

Screenshots