We are working on a new version of a website. The current version is indexed by google, everything looks fine. The new version will have more or less the same content & links, but we are changing the design slightly & implement a new architecture (eg. using AngularJS etc). We want to test the new version which is still under development to see how google will fetch it. We added a robots.txt file to 'disallow /' because we don't want google to index our development server.
Is it safe or recommended to use the "fetch as google" tool before the release of the new version?
PS: I think this post suggests to wait until the release: Manual "Fetch as Google" or better wait? But then, how could we test that google will see all the content correctly?