Fixed crawling of projects with publicPath != "/"

[kantenkugel]

As connect-history-api-fallback would try to serve /200.html file for any non-found request, it would just fail and return a 404 page as pages generated with publicPath other than "/" would have the 200.html file within the publicPath subdirectory, not root. This commit wraps the historyApiFallback inside the publicPath route.

There is an additional optional step that I didn't implement here:
Switching the order of express.static() and the historyApiFallback.
Currently, it tries to serve the 200.html file first (if there is a GET request for text/html). Only after that fails (for non-html requests), files out of the static dir are served. This might be the wrong order as some static html-files (inside of the public folder) will never get served. Best would be to reorder those 2 to first serve existing static files, and only then fall back to the 200.html file

[kantenkugel]

if requested i can swap the order of the 2 middlewares (as described above) and add the commit to this PR

[geelen]

Yeah i've been having real trouble with the order of the loaders. This is where some proper tests would be super handy. I think this is good to merge, but let's leave the order of the loaders for now—I'll have a play with it soon and make sure it works on my two manual test projects

[kantenkugel]

Ok I'll leave the PR as it is then

[kantenkugel]

After thinking about it a little more:

You probably don't need to serve static html files anyway, as those are not from react and don't need to be snapshotted by react-snapshot. You only need external resources for your 200.html file (the built main.js file for example) and those are fine being served after the static 200.html for all html request.

Then again: if you have a link inside your react-driven app to a static html, react-snapshot will open the 200.html with the incorrect URL and will probably render some 404 site of your app which will replaces the static file in the output.

One option would be to re-enable the dot-rule for connect-history-api-fallback, as react normally doesn't generate *.html routes.
Only problem then is that the error message about render() not being called is printed out.

[geelen]

Yeah I'm not sure if that's better. Potentially adding data-react-snapshot-nofollow attribute to links or adding paths to the exclude (you can use wildcard matches there too) is enough...

[geelen]

Let's move that discussion elsewhere for now. I wanna merge & release this.