I have a client who insisted that we keep our new development separate from the main branches for the entirety of 2016. They had 3-4 other teams working on the application in various capacities. Numerous large changes have been made (switching how dependency injection is done, cleaning up code with ReSharper, etc). It has now fallen on me to merge main into our new dev branch to prepare to push our changes up the chain.
Is there an approach I can take that will make this easier for me?
To clarify, I expressed much concern with this approach multiple times along the way. The client was and is aware of the difficulties with this. Because they chose to short on QA staff (1 tester for 4 devs, no automated testing, little regression testing), they insisted that we keep our branch isolated from the changes in the main branch under the pretense that this would reduce the need for our tester to know about changes being made elsewhere.
One of the bigger issues here is an upgrade to the angular version and some of the other third party softwares --unfortunately we have no come up with a good way to build this solution until all the pieces are put back into place.