Testing UI is usually tricky and is generally done only on the final application as validation tests.
Nevertheless a pure Eclipse 4 UI plugin (that can easily be mixed with other legacy Eclipse 3 plugins), provides POJOs that do not depend on any Eclipse RCP stack. In these conditions it is possible to mix different UI POJOs in a simple way so as to test their interactions (as integration tests).
Akuiteo is a french company that publishes Akuiteo ERP, a software management platform for services companies.
Our main front-end product is an Eclipse RCP-based application. This product was launched in 2007, and our last technical migration (from RCP 3.5 to RCP 3.7) occured in 2012.
After 5 years, it was time to enter in a new era by changing the engine and migrating to e4 !
I'll present the different steps, the doubts, the pitfalls and eventually the success !