JedWatson
Check `document` is not undefined before requiring `hammerjs` for SSR
@bradleyflood You've made a bunch of statements without any backing... I'm not sure why you think "Checking for only window is quite standard." I see no evidence behind that.
On the contrary, I've frequently seen that document is what's checked. window may be mocked for many reasons such as when using webpack's require.ensure. Obviously I have no stats for whether window + document or window or document are more commonly used, but here are at least a number of SSR blog examples that use document alone, without window. It's not the best evidence, but at least shows the community does in fact check for document
https://medium.com/front-end-hacking/preparing-react-components-for-server-side-rendering-18901d09784c https://survivejs.com/webpack/output/server-side-rendering/ http://jxnblk.com/writing/posts/static-site-generation-with-react-and-webpack/ https://github.com/markdalgleish/static-site-generator-webpack-plugin
Also, not sure what this problem is: Another team may even be mocking document = {} on their server side and then they will be in the same scenario you are too.
Suppose you were expecting require('hammerjs') to not be called. This means you previously had typeof(window) === 'undefined'. Regardless of whether you mocked document, this still happens post-PR.
Now suppose you were expecting require('hammerjs') to be called. This means you previously mocked window. If you have also mocked document={}, then the require statement is still called.
So I'm not sure what the problem you're stating is.
The only scenario that has a breaking change is if they were expecting require('hammerjs') to be called, had mocked window and did NOT mock document. I'm not entirely sure this scenario is a frequent use case IMHO...
@JedWatson I submitted this PR over 3 months ago. Any chance you could spend 10 minutes to review and let me know if this is mergeable? Thanks!