= Error Handling Guidelines

== Exception Handling

* **Log or Rethrow**: When catching exceptions, either rethrow them or log them. Include the root cause.
+
[source,java]
----
catch (SomeException e) {
    throw new AnotherException("..details..", e);
    // OR
    LOG.error("...context...", e);
}
----

* **No Empty Catch Blocks**: Completely empty catch blocks are VERY suspicious. Do not "swallow" exceptions unless you are absolutely sure.
    * Such "normal exceptions" are often indications of using the wrong API (e.g., throwing an exception for an expected condition instead of returning empty/optional).

* **Tests**: In tests, typically propagate exceptions (`throws SomeException`) so the test fails if it occurs.
    * To test for an exception, use `Assert.assertThrows()`.

* **NullPointer**: Never catch `NullPointerException`. Fix the code instead.