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avoid-excessive-expressions

added in: 1.14.0
warning
Pro+
preset: recommended

Warns when a condition has excessive expressions.

Excessive expressions do not affect the result of the condition and can be simply removed.

Example​

❌ Bad:

void fn() {
  final num = 1;
  final anotherNum = 2;

  // LINT: This expression is redundant. Try updating this expression or replacing it with a different expression.
  if (anotherNum == 3 && anotherNum != 4) {}

  // LINT: This non-null check is redundant since the next expression implicitly checks for a non-null value. Try removing this expression or replacing it with a different expression.
  if (num != null && num is int) {}

  // LINT: This null check is redundant since the next expression implicitly checks for a null value. Try removing this expression or replacing it with a different expression.
  if (num == null || num is! int) {}

  // LINT: This expression is redundant. Try updating this expression or replacing it with a different expression.
  if (5 < anotherNum && anotherNum > 4) {}
}

✅ Good:

void fn() {
  final num = 1;
  final anotherNum = 2;

  if (anotherNum != 3 && anotherNum != 4) {} // Correct, different condition
  if (num is int) {}
  if (num is! int) {}
  if (2 < anotherNum && anotherNum < 4) {}
}

Additional Resources​