One year after switching from Java to Go

I've been using Go for a while now. The biggest headache is error handling. I don't care what the "experts" say, having exception handling is so, so, so much cleaner in terms of error handling. Checking for err is simply bad, and trickling errors back up the call stack is one of the dumbest experiences in programming I've endured in multi-decades. If they are willing to add generics, they should add exception handling as well.

To each their own. I'm not going to claim to be an expert, but as somebody who's been coding since the 80s it was a breath of fresh air to see Go do what I wanted languages to do all long instead of ramming exceptions down my throat. I have problems with Go (examples: slice behavior and nil type interfaces) but error handling is not one of them.

What challenge did you run into with exception handling?

I'm curious because I've never felt it being onerous nor felt like there was much friction. Perhaps because I've primarily built web applications and web APIs, it's very common to simply let the exception bubble up to global middleware and handle it at a single point (log, wrap/transform). Then most of the code doesn't really care about exceptions.

The only case where I might add explicit exception handling probably falls into a handful of use cases when there is a desire to a) retry, b) log some local data at the site of failure, c) perform earlier transform before rethrowing up, d) some cleanup, e) discard/ignore it because the exception doesn't matter.

In Go, b) is really common. Most of my code will annotate a lower error with the context of the operation that was happening. You’ll ideally see errors at the top level like: “failed to process item ‘foo’: unable to open user database at ‘/some/path’: file does not exist” as an example.

Here, the lowest level IO error (which could be quite unhelpful, because at best it can tell you the name of the file, but not WHY it’s being opened) is wrapped with the exact type of the file being opened (a user database) and why the database is being opened (some part of processing ‘foo’, could even generate better error message here).

Although this is a bit of work (but in the grand scheme of things, not that much), it generates much better debugging info than a stack trace in a lot of situations, especially for non-transient errors because you can annotate things with method arguments.

I think the common complaint of ‘if err != nil { return err }’ is generally not the case because well-written Go will usually prepend context to why the operation was being performed.