Program logic bugs vs input/environmental errors

[Walter Bright via Digitalmars-d]

On 9/28/2014 9:23 AM, Sean Kelly wrote:
> Also, I think the idea that a program is created and shipped to an end user is
> overly simplistic.  In the server/cloud programming world, when an error occurs,
> the client who submitted the request will get a response appropriate for them
> and the system will also generate log information intended for people working on
> the system.  So things like stack traces and assertion failure information is
> useful even for production software.  Same with any critical system, as I'm sure
> you're aware.  The systems are designed to handle failures in specific ways, but
> they also have to leave a breadcrumb trail so the underlying problem can be
> diagnosed and fixed.  Internal testing is never perfect, and achieving a high
> coverage percentage is nearly impossible if the system wasn't designed from the
> ground up to be testable in such a way (mock frameworks and such).

Then use assert(). That's just what it's for.