HighFile-scopeKotlin Plug & play

Replace null assertions with explicit null handling

Avoid the !! operator. Prefer safe calls, Elvis (?:), early returns, or explicit exceptions with a clear message.

Why this matters

Null assertions crash at runtime and hide intent. Explicit handling makes failure modes predictable and testable.

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

Avoid

val len = name!!.length

Prefer

val len = name?.length ?: return Result.failure(IllegalArgumentException("name is required"))

Bad

user!!.email

Good

val email = user?.email ?: throw IllegalStateException("missing email")

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