cause a Test Crash

https://docs.fabric.io/apple/crashlytics/test-crash.html

when used crash() to view how it logged, it doesn’t logged at first. Second try(after the connection from Xcode to simulator is ended) succeeded

Crashlytics.sharedInstance().crash()

Crashlytics.sharedInstance().throwException()

How to read userInfo of error

on Keys / logs button

set to the Keys!

Crashlytics log non-fatal errors

https://docs.fabric.io/apple/crashlytics/logged-errors.html

• logged errors are grouped by the NSError domain and code
• For any individual app session, only the most recent 8 logged NSErrors are stored.
• When a crash occurs and the app is relaunched, the logs we retrieve from disk are those that were written right up to the time of the crash. When you log an NSError, though, the app does not immediately terminate. Because we will only send the logged error report on the next app launch, and because we must limit the amount of space allocated for logs on disk, it is possible to log enough after an NSError is recorded so that all relevant logs are rotated out by the time we send the report from the device.
• counting the number of times an event is occurring->  Answers custom events.