Migrating from Objective-C to Swift. Learnings and Pitfalls

I’ll start with what Apple says about “Swift”.

“Swift is a new programming language for iOS, macOS, watchOS, and tvOS apps that builds on the best of C and Objective-C, without the constraints of C compatibility.”

The elegance of swift compelled almost every developer to try it out in at least one of his apps. And considering its benefits it has already become the developer’s first choice. Hence as a team, we took a courageous decision to migrate to Swift completely. Courageous because the task of migration has the number of challenges (some of them were unknown to us at that time). Known were as follows:

• Every member of the team was new to the language.

• Codebase which was to be migrated was of more than 100000 LOC.

• Migration has to happen for a very stable live app code into a completely new language which involves a lot of effort and bandwidth from the dev team thereby depleting the pace of Product Pipeline.

We decided to take this challenge and moved to almost complete code to swift. Why “Almost”? You’ll come to know as you read on.