LowFile-scopeDart Plug & play

Handle StateError from firstWhere operations

Always provide `orElse` to firstWhere (or use a safe helper) when the match may not exist.

Why this matters

Avoids StateError at runtime and makes absence explicit.

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

Avoid

final user = users.firstWhere((u) => u.id == id);

Prefer

final user = users.firstWhere(
  (u) => u.id == id,
  orElse: () => defaultUser,
);

Bad

list.firstWhere(test)

Good

list.firstWhere(test, orElse: () => fallback)

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