app environment_variables are invoked every time a new tap is chosen under the Application screens

[jcvrabo]

When viewing an application, every time a new tab is chosen (Summary, Log Stream, Revisions, Routes, Variables, Services or Events), it seems like the environment_variables app endpoint is being invoked, issuing a new audit.app.environment.show event for the app every time.

This seems unnecessary and ends up "polluting" the events for the app.

Reproducing

Simply click on an app, going to its details screens and click around any of the side tabs to visualize its screen (logs, revisions, etc.). Finally click on the events tab and you will see one audit.app.environment.show event reported for every single tab click done.

Expected behaviour

It would be expected that only when clicking the Variables tab the event would be issued (meaning, only then would the environment_variables call be executed)

Observed behaviour

/v3/apps/:guid/environment_variables seems to be called every time a tab in application is clicked.

[norman-abramovitz]

triaging

[norman-abramovitz]

My CF testing environment is down. Please test in your local environment.

[nabramovitz]

Reopening: the merged fix (41d4352) turned out to be ineffective in the running app — live verification showed the app-detail shell still remounts on every tab switch. Root cause found one level up: the reuse strategy returns false for the root ActivatedRouteSnapshot node (component null vs. absent marker undefined), which makes Angular recreate the whole route tree on every navigation and silences the reuseRoute markers. Follow-up fix incoming.

[nabramovitz]

This should be reopened: the merged fix (41d4352) turned out to be ineffective in the running app — live verification shows the app-detail shell still remounts on every tab switch (component instance replaced, env-vars re-fetched each click).

Root cause is one level above the markers: CustomReuseStrategy.shouldReuseRoute returns false for the root ActivatedRouteSnapshot node (component is null there, while an absent reuseRoute marker is undefined, and null === undefined is false). Angular then recreates the entire ActivatedRoute tree on every navigation, so every router-outlet below rebuilds and the new reuseRoute markers never get a say. Follow-up fix (normalize the comparison) incoming.