HighFile-scopeC# Plug & play

Use specific exception types over generic Exception

Throw and catch the most specific exception type available; avoid catching or throwing System.Exception unless rethrowing.

Why this matters

Specific types enable precise handling, better logging, and safer retries.

Side-by-side examples engineers can pattern-match during review.

Avoid

catch (Exception ex) { /* handle all */ }

Prefer

catch (InvalidOperationException ex) { /* corrective action */ }
catch (HttpRequestException ex) { /* retry/backoff */ }

Bad

throw new Exception("failed");

Good

throw new InvalidOperationException("invalid state");

From the same buckets as this rule.

Critical
Avoid equality operators in loop termination conditions
Check if loops use equality operators (== or !=) in termination conditions. These can lead to infinite loops if the condition is never met exactly. Instead, use relational operators like < or > for safer loop termination.
error-handlingreadability-refactor
Critical
Avoid Returning Null in Non-Async Task Methods
Returning null from a Task or Task<T> method causes a NullReferenceException if awaited. Use Task.CompletedTask or Task.FromResult<T>(null) instead.
error-handlingreadability-refactor+1
Critical
Avoid Using Boolean Expressions in `except` Statements
Detect `except` clauses that use `or` or `and` to catch multiple exceptions. This does not work as intended. Recommend using a tuple of exceptions instead.
error-handlingstack-python