HighFile-scopeC# Plug & play

Use TryParse for string conversions

Prefer TryParse-style APIs for user/IO input instead of Parse, and validate culture/format where applicable.

Why this matters

Avoids exceptions as control flow and handles invalid input gracefully.

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

Avoid

var n = int.Parse(value);

Prefer

if (!int.TryParse(value, out var n)) return BadRequest("invalid number");

Bad

DateTime.Parse(s)

Good

DateTime.TryParse(s, out var dt)

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