App shouldn't exit if error doesn't implement ExitCoder

[awsmsrc]

Current behavior:

Even if the error returned doesn't implement ExitCoder the app exits with an exit status of 1

• introduced here: e9688813
• further info here: How to Run without exiting on error? #565

Expected behavior

the app will return the error but not exit so it can be introspected as follows

err := app.Run()
if err != nil {
  if err.IsInterestingToMe() {
    reportInterestingData()
  } else {
    exit(1)
  }
}

Usecase

if the users token has expired, prompt for a email/password, generate a new token and re run the command

Alternative option

Allow for a custom HandleExitCoder to be specified

[awsmsrc]

Happy to help with whatever implementation is decided here, if it can help get things moving :)

[jszwedko]

@awsmsrc 👍 thanks for filing this -- it reminded me to take a deeper dive into #565 and I came to the same conclusion you did. #595 adjusts this behavior to only exit for ExitCoders.

[kklipsch]

So #595 has the effect of ignoring errors coming out of the action function unless they meet the ExitCoder interface? That seems weird and wrong. Why not change the action function to explicitly require an ExitCoder?

For the record, both behaviors introduce regressions. If someone is programming against the current release changing this behavior breaks their code.

[jszwedko]

@kklipsch it doesn't ignore the errors, rather it propagates them up to the App.Run() method so that the caller can decide what to do. You can use App.RunAndExitOnError as a convenience to exit with a code of 1 if desired.

I agree that #595 breaks the interface, but #565 broke it initially and I think the least harmful approach is to put the behavior back to not surprise people who are upgrading (as well as not removing the previously supported feature of deciding what to do with errors).

Closing this since #595 has been merged in.