Exception Handling for NoSuchElementException in Collection.first()

[hussainmohd-a]

While working with the Collection.first() method, there is a potential risk of encountering a NoSuchElementException. This can lead to unexpected runtime errors, and it's important to handle this exception gracefully.

Below is one such case

Abort message: 'JNI DETECTED ERROR IN APPLICATION: JNI CallStaticVoidMethod called with pending exception java.util.NoSuchElementException: List is empty.
  at java.lang.Object kotlin.collections.CollectionsKt___CollectionsKt.first(java.util.List) (_Collections.kt:214)
  at boolean com.celzero.bravedns.service.BraveVPNService.boundNetworkMeteredCheck(com.celzero.bravedns.data.ConnTrackerMetaData) (BraveVPNService.kt:658)
  at boolean com.celzero.bravedns.service.BraveVPNService.isConnectionMetered(com.celzero.bravedns.data.ConnTrackerMetaData) (BraveVPNService.kt:646)
  at intra.Mark com.celzero.bravedns.service.BraveVPNService.flow(int, long, java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String) (BraveVPNService.kt:2526)

    in call to CallStaticVoidMethod'
      #10 pc 00000000002c7f18  /data/app/~~9d4WHB26aQz9Q1V3QaFyLQ==/com.celzero.bravedns-3ABWzm5SGa1ZKhlF54M0IQ==/base.apk

[hussainmohd-a]

To mitigate the risk of a NoSuchElementException, it's recommended to check if the collection is not empty before calling first(). This ensures that the operation is safe and won't result in an exception.

[ignoramous]

mitigate the risk of a NoSuchElementException, it's recommended to check if the collection is not empty before calling first().

This won't mitigate it but merely reduce the occurrences due to TOCTOU (time-of-check to time-of-use; that is, at the time of checking for Collection.isEmpty it is not empty, but at the time of using it Collection.first it may be empty due to data races). The only way is to catch the Exception.

[hussainmohd-a]

The issue of NoSuchElementException in the code has been resolved by replacing first with firstOrNull, ensuring safe handling of potentially empty collections throughout the app.