HighFile-scopeJava Plug & play

Add comprehensive null checks for parameters

Validate method inputs up front with null checks or use Objects.requireNonNull and meaningful messages.

Why this matters

Prevents NullPointerException, documents preconditions, and fails fast near the source.

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

Avoid

String cityLower = city.toLowerCase();

Prefer

Objects.requireNonNull(city, "city required");
String cityLower = city.toLowerCase();

Bad

user.getAddress().getCity().toLowerCase()

Good

String city = Optional.ofNullable(user)
    .map(User::getAddress).map(Address::getCity)
    .orElse("unknown");

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