Hello,
I have a similar problem now using Vaadin 14.0.0 with Spring Boot (e.g. the standard starter app or a simple app only using the flow components).
The same application itself starts normally (like it did using Vaadin 13), but then there are the following steps that really take too much time:
... dev-updater : Scanning classes to find frontend configurations and dependencies...
... dev-updater : Visited 7144 classes. Took 6957 ms.
… and most of all …
... dev-webpack : Starting webpack-dev-server, port: 58435 dir: C:\development\workspace\...
...
... ----------------- Frontend compiled successfully. -----------------
...
... a.e.p....Application : Started ...Application in 18.609 seconds (JVM running for 19.57)
To me it seems that there are dev-updater and dev-webpack doing much work to compile/transpile the standard Vaadin frontend stuff every time - even if I do not use any custom front end code until now and i did not change anything on the frontend side from one start to the next.
Putting the vaadin.whitelisted-packages property into my dev property file seemed to help as before all took around a minute before, but I see no point in waiting nearly 20 seconds every time i want to start a small standard Vaadin Spring Boot app out of the IDE.
Could it be that it will get better when going to Version 14.0.0.1?
Is this version already officially released?
Or is there a way to tell webpack not to do all of this this everytime I start the application while developing, like it also already skips “npm install” after the first time…?
I remember Vaadin 8 having the same possibility to transpile frontend code from es6 to es5 or similar, but it was possible to let it do this only when using the Maven profile “production-mode” and to switch it off somehow for other cases…