Fix usage of custom favicon

[jeffcarbs]

Fixes #581

This line (https://github.com/kadirahq/react-storybook/blob/master/src/server/index.js#L69) hard-codes the favicon to be pulled from /node_modules/@kadira/storybook/dist/server/public/favicon.ico.

This update first checks the specified static files for a favicon.ico and uses that if one is found. Otherwise, it falls back to using the default storybook favicon. The tricky part here is that it seems that the first call to app.use(favicon) wins, so we need to do the default last.

[thani-sh]

Awesome! I'll just check it out locally in a few hours and merge

[arunoda]

Is this something documented?
I mean it's better to have a variable called hasCustomFavicon and act accordingly.

[jeffcarbs]

It's just something I noticed, but you're right that it's not super clear. I'll update this to use hasCustomFavicon based on your feedback.

[arunoda]

@jcarbo I think we need to do the same in the build.js as well.
See: https://github.com/kadirahq/react-storybook/blob/8610bca7b0cbba93fa6c770dad4404325be6e549/src/server/build.js#L56

[jeffcarbs]

@arunoda - Looks like that line just copies the favicon from /public/favicon.ico into the main outputDir directory. If you define a static dir, all those assets will then be copied into that same directory afterward (https://github.com/kadirahq/react-storybook/blob/8610bca7b0cbba93fa6c770dad4404325be6e549/src/server/build.js#L65-L74) so if you've defined a favicon.ico it will override the default.

Given that, it looks like this is only an issue in development which is using express. When the build is compiled statically your custom favicon.ico will be the one that gets built.

[jeffcarbs]

Updated! I built and tested this in my app and it works as expected.

[arunoda]

@jcarbo yep. You've a solid point in that.