Git for iOS Developers

First given at iOS Dev UK, Aberystwyth, 2013

1. Git for iOS Developers Simon Whitaker, @s1mn
2. // TODO • Enhance your daily Git skills • Learn some tips for coping with diff and merge problems • Look at some workflow options for small teams • If we have time, some lulz
3. In the beginning there is Xcode...
4. Git in Xcode • Basic git support • Check out • Commit • Branch • Push/Pull
7. Dedicated Git GUIs SourceTree Tower
8. Dedicated Git GUIs SourceTree
10. The best Git client Terminal
11. Terminal Advantages • Greater flexibility • Add custom git commands • Third-party add-ons
12. Specifying revisions git checkout master git checkout v1.2 git checkout 6a54bc0 git checkout master@{yesterday} git checkout master@{2 hours ago}
13. git bisect • Binary search for bugs • Give it a “good” and “bad” ref, it’ll pick a commit half way between the two for you to test • Test, mark it good or bad, repeat
14. $ git bisect start $ git bisect good @{yesterday} $ git bisect bad Bisecting: 14 revisions left to test after this (roughly 4 steps) [368c20e61b675494d6274afe6c6ddfb9 30f3e290] Make awesome change to teh codez
15. $ git bisect bad Bisecting: 6 revisions left to test after this (roughly 3 steps) [8c20e61b675494d6274afe6c6ddfb930 f3e29036] Added new design assets
16. Automating git bisect $ git bisect start $ git bisect good @{3 days ago} $ git bisect bad $ git bisect run command args
17. $ git bisect start $ git bisect bad $ git bisect good @{yesterday} $ git bisect run xctool clean test Who broke the tests? facebook/xctool
18. Aborting git bisect $ git bisect reset
19. Add git commands • Write a script, save it somewhere • Make it executable • Add entry to [alias] section of ~/.gitconfig
20. Example: release notes $ git release-notes 1.1 - Add new app icon - Fix Facebook SDK issue - Add Korean localization simonwhitaker/dotfiles
21. Example: is ancestor $ git is-ancestor ba6d524 827dd3a ba6d524 is an ancestor of 827dd3a simonwhitaker/dotfiles
22. hub $ brew install hub $ alias git=hub $ git clone user/project [ Clones git://github.com/user/project.git ] $ git create [ Creates repo on GitHub, sets remote ] github/hub
23. version.sh • Set the version number of a build at build time, based on git tags • http://stuff.bondo.net/post/7769890357/ using-build-and-version-numbers-and-the- art-of gist.github.com/osteslag/1089407
24. Difficult Diffs and Murderous Merges
25. .strings files Binary files a/MyApp/en.lproj/ Localizable.strings and b/MyApp/ en.lproj/Localizable.strings differ
26. .strings files • Unicode text, stored as UTF-16 • Use a third-party diffing tool • Vimdiff: git difftool -t vimdiff • Kaleidoscope: git difftool -t ksdiff • Store as UTF-8
27. .pbxproj, .xcdatamodel • Merges are hell :-( • Kaleidoscope does a good job
28. .pbxproj, .xcdatamodel • Google “git merge pbxproj” • http://stackoverflow.com/questions/2729109/ • “Should I merge .pbxproj files with git using merge=union [in .gitattributes]?”
29. No
30. .xib • Can merge in Xcode 5! (Thanks, iOS Dev Weekly) • http://nilsou.com/blog/2013/08/07/xcode-5- finally-makes-interface-builder-a-viable- option-for-teams/
31. Workflows for small teams
32. Git workflows • Everything on master • git-flow • github-flow
33. Everything on master • Fine if you’re a sole developer • Still worth using branches for experimental stuff • Don’t forget, it’s easy to branch retrospectively
34. git-flow • master, develop, feature & release branches • CLI tool hides the complexity • Fine if you have a periodic release cycle • In small teams, often better to have a formal process than an informal one nvie/gitflow
35. GitHub Flow • What GitHub do • master is always deployable • Develop on a branch, merge to master via pull request then immediately deploy • Great for web-based stuff like GitHub • Do clients want a new adhoc build after every feature?
36. Thanks! simon@blackpixel.com @s1mn