If you are looking at migrating your code from Ionic Framework version 4 to the soon to be released Ionic Framework version 5, then I have some good news for you: it should require almost no work.
The Ionic Framework team has been maintaining a breaking changes document. However, these changes have also been expressed via deprecation warnings that show in the console when you are running your app. The end result being that the Ionic Framework team has been building your migration path right in to the framework.
Here is what I suggest you do:
- Make sure your application is using the latest version if Ionic Framework version 4 (currently 4.11.10).
- If your application is using Angular, make sure you are on the latest Angular 8 patch level. If your application is currently using Angular 7, please see our release notes for tips on upgrading to Angular 8.
- Run the application with the appropriate browser's developer tools connected and pay attention to the console tab.
- Take note of any deprecation warning coming from your application. It will contain examples of the deprecated code along with instructions on how to fix them.
- Follow those instructions until you no longer receive deprecation warnings.
At that point, your code should be ready for version 5 of the Ionic Framework. Of course, code is complex, and there might be an edge case that the team has not anticipated fully. If you run into that, please let us know.