This repo exists to demonstrate a bug.

nmp run dev and browse to: http://localhost:3000/en-us/z/a.html

You will see that the getStaticProps runs on the server and produces the correct props on initial render:

{ product :  {aye: 'bar'} }

But then Next makes another XHR request to en-us/z/a.html.json. The server 308-redirects this to /en-us/z/a.html, which returns a response in html format.

The client side of Next attempts to parse this response as JSON and winds up with {}, which then becomes the Page's new props. In effect, all props are wiped out.

This bug goes away if any of the following things change:

• rename middleware.ts (which does nothing) to another filename
• change trailingSlash in the config to false.
• request http://localhost:3000/en-us/z/a/ instead of using the .html suffix.

Unfortunately, our app requires all of these things. So we have to deal with this Next bug.