{"id":25996,"date":"2019-07-17T16:21:55","date_gmt":"2019-07-17T20:21:55","guid":{"rendered":"https:\/\/mjtsai.com\/blog\/?p=25996"},"modified":"2019-07-17T16:23:02","modified_gmt":"2019-07-17T20:23:02","slug":"branches-and-continuous-integration","status":"publish","type":"post","link":"https:\/\/mjtsai.com\/blog\/2019\/07\/17\/branches-and-continuous-integration\/","title":{"rendered":"Branches and Continuous Integration"},"content":{"rendered":"

Soroush Khanlou<\/a> (tweet<\/a>):<\/p>\n

A problem presents itself, however. You need to build a feature that takes 1,000 lines of code, but you’d like to merge it in in smaller chunks. How can you merge the code in if it’s not finished?<\/p>

Broadly, the strategy is called “branch by abstraction”. You “branch” your codebase, not using git branches, but rather branches in the code itself. There’s is no one way to do branch by abstraction, but many techniques that are all useful in different situations.<\/p>

[…]<\/p>

Of course, the humble if<\/code> statement is also a great way to apply this technique; use it liberally with feature flags to turn features on and off. (A feature flag doesn’t have to be complicated. A global constant boolean gets you pretty far. Feature flags don’t have to come from a remote source! However, I would recommend against compile-time #if<\/code> statements, however. Code that doesn’t get compiled might as well be dead.)<\/p><\/blockquote>\n\n

Branches are just not very useful for managing features or major releases for which development will take a long time (during which you will keep working on the shipping version). They’re great when you want to make a bug fix release based on an old version, and thereafter plan for the branch to die. But, otherwise, you spend a lot of time merging changes back and forth between two active branches and still end up with a potentially difficult integration at the end. It’s better to use feature flags and potentially extra Info.plist<\/tt> files and Xcode targets to support simultaneous development of multiple versions.<\/p>\n\n

Previously:<\/p>\n