My employer has a fair amount of Apex code that was written for us three to five years ago. We haven't been updating the API versions of the older classes and new code has been added, so we have quite a mix of API versions out there (versions 13-30).
This question got me to thinking about how best to bring the versions up to date. How should we approach this?
- Update everything to the latest version all at once.
- Update the oldest classes to some intermediate version(s) first. (if so, which)
- Update classes to the latest version one at a time (recognizing that dependencies may force other updates)
- Some other process not listed here
Note: Alan Morey has compiled a list of where to find the past Salesforce release notes here.