Swallowed exception

What it looks like

• An empty catch, or one that only logs.
• A rethrow deleted from a catch block.
• catch { return partial; } where partial is whatever had been built so far.

Why it survives review

The code looks more robust, not less: there is a try, there is a catch, somebody clearly thought about failure. And on every input that does not fail — which is nearly all of them — it behaves identically. The damage is that a partial result propagates as though it were complete.

How to see it

1. For every catch, ask what the caller now believes. If the answer is 'that it worked', the catch is a defect.
2. Distinguish handling an error from hiding one. Logging is not handling.
3. Check that the value returned from a catch is distinguishable from a real result.

A minimal pair

On a failing input the correct build throws; the defective one returns the half-built result.

Practise it

1 diff in the corpus carry this class. They are not listed, because knowing which diff contains what would make finding it a comprehension question about this page.