Version Control

1. Version Control TFS Without Fear

2. Getting To Know You • Who here uses version control? • What tools do you use? • Why do you use it?

3. Why Talk About Version Control • Most colleges don’t teach it • Is an integral part of a programmers daily life • Should be using it multiple times per hour • Many people do not take full advantage • Many people use it wrong

4. What it is and does • A repository containing a project’s history • Tracks project artifacts’ history • What does that mean? • It keeps a record of each change to a project’s artifacts • The first step to CI

5. What it isn’t • Backup system

6. Why We Use It • Track changes throughout product life • task completion • bug fixes • Story/feature completion • Allows Teamwork • multiple people collaborate on project • Can recover from faulty commits • rollback

7. Why Track History? • Frequently need to know • When was feature added? • When was bug fixed? • When did we release?

8. Why would we need to know that? • Where are we in development? • Release notes • What was included in release? • When was bug introduced? • Hot-Fixes

9. How we use it • We commit (check in) code that is “done”, along with the associated tests • Tests all pass (not just the new ones) • Code is refactored

10. What we store • Whatever we need to successfully build the system • Source code • Test code • Build files • Project definitions • Configuration files

11. What we do not store • Anything the build process can create • NuGet packages • Compiler generated artifacts • dlls • exes • Etc.

12. How version control works • Various implementations • Distributed • E.g., GIT, Mercurial • Out of scope for this presentation • Centralized • E.g., CVS, Svn, TFS • Server based workspace • Local workspace

13. Centralized Repository • Repository on some server holds history • Server based workspace • The server tracks all changes you make • Requires connection to server while working • Local workspace • Your local workspace tracks all changes you make • No connection necessary until commit • We discuss centralized local workspace

14. TFS Local Workspace • Maps repository location local folder • Adds hidden folder to local machine • $tf • Tracks changes in $tf • Commit moves changes to repository

15. When to Commit • When TASK is done • When BUG is fixed • Do not wait until Story is done

16. Do NOT End Day Without Commit • Why Not??? • If can’t finish in a day, task too big • You probably don’t fully understand problem • Your code will be too complex • Other problems exist

17. Example • Jane works on big task • Doesn’t finish, goes home • Code is on her work station • Does not work next day • Got sick, hit by bus, … • Team is stuck waiting on task

18. Solution • Delete all of your code • Start over tomorrow • Break task into effort < 1 day • Complete manageable tasks • Commit completed task before leaving • Some would assign task to different person

19. Commit – What it Means • Your code is done • For the current task • Your code is tested • You put your seal of guarantee on the code • Now you check in to repository • Code is available to team

20. Commitment to Your Team • You make a promise to your team that your code is tested and works to specification

21. Interesting Observation • You should be able to deploy a working subset of the system from any commit

22. How to Commit • Select files to commit • Usually 2: test, production • If more, probably have poorly defined tasks • Link to task • Write good comment

23. Write Good Commit Comment • A. K. A. – Log message • To help a programmer in the FUTURE • Task description does part • Depends on GOOD task description • What you did • Why you did it

24. Workflow – The College Way • Write some code • Run the code to see if it works • Fix as necessary • Repeat until assignment is done

25. Workflow – Single Professional Programmer • Refresh from repository • Write test code • Edit production code • Run tests • Loop to 3 until all tests pass • Loop to 2 until task is complete • Commit to repository Some might swap 6 & 7

26. Things to Notice – Working Alone • Refresh from repository • Your local workspace matches the latest in repository exactly • You do your work as described above • You commit • your local workspace matches the latest in repository exactly • Life is Good

27. Workflow – Multiple Professional Programmers • Refresh from repository • Write test code • Edit production code • Run tests • Loop to 3 until tests pass • Loop to 2 until task is complete Now what? Ready to commit?

28. Things to Notice – Working on Team • Refresh from repository • Your local workspace matches the latest in repository exactly • You work as though you are alone • You commit • Your local workspace might not match repository • Code in repository might not even compile • What the ???

29. You Need Extra Steps • Other programmers make changes • Possibly including your current file • Facilitates team projects

30. Workflow – Multiple Professional Programmers - Continued • refresh from repository • merge as necessary • run tests • edit production code to pass tests • run tests • loop to 10 until all tests pass • loop to 7 until all tests pass • commit to repository

31. 1st Step to CI? • What is CI? • Continuous Integration • On Commit • Build server builds code • Runs unit tests • Reports results • If your code breaks the build, but is in VC your team is dead in the water

32. TFS Solution • Gated Build • Shelves changes • Builds shelveset • IFF build passes – commits • Else – reports error

33. Demo • CI Build • CI Build w/ error • Gated Build • Gated Build w/ error

34. Try It • MSDN subscription • Visual Studio Online - free • http://www.visualstudio.com/products/visual-studio-online-overview-vs

35. Learn More • http://msdn.microsoft.com/en-us/library/vstudio/ms181237.aspx • Contact • CAndersen@planetds.com • Blog: http://geekswithblogs.net/ChuckAndersen