+++
title = "Things I Learnt The Hard Way - It's Better To Let The Application Crash Than Do Nothing"
date = 2019-06-24
[taxonomies]
tags = ["en-au", "books", "things i learnt", "exceptions", "error handling"]
+++
Although that sounds weird, it's better to not add any error handling than
silently capturing errors and doing nothing.
<!-- more -->
For example, a (sadly common) example of Java code:
```java
try {
something_that_can_raise_exception()
} catch (Exception ex) {
System.out.println(ex);
}
```
This does nothing to deal with the exception -- besides printing it, that is.
The example may be a bit bad, 'cause Java forces capturing exceptions on
functions that throw exceptions and it forces functions to mark themselves as
throwing exceptions if there a `throw` in them.
But Python doesn't have this restriction and people _still_ try to capture
exceptions for doing absolutely nothing -- and, worse, just keep the execution
going.
If the language allows it, you should let the application crash due the lack
of error handling -- as long as you don't have any idea on how to handle it.
Then, when they crash, you can think of a way to deal with it, instead of
silently capturing it and doing nothing.
Also, keep in mind to not go forth and capture _every_ exception/error in a
single take -- like the example above, which will capture every exception, or
like `except Exception` in Python. This last example actually happened to me
when another developer added this "broad except"[^1] in a network code and, at
some point, the code would get into the capture all the time. We checked every
cable, every connection, every interface, till I noticed there was a syntax
error in the code. In Python, syntax errors raise exceptions and, because we
had a "capture all exceptions", we lost some pretty good time looking for the
problem in the wrong place.
[^1]: As called by Pylint.
{{ chapters(prev_chapter_link="/books/things-i-learnt/interface-changes", prev_chapter_title="Beware of Interface Changes", next_chapter_link="/books/things-i-learnt/handle-it", next_chapter_title="If You Know How To Handle It, Handle It") }}
