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avoid-self-compare

added in: 1.1.0
warning
Free+
preset: recommended

Warns when a comparison has both sides exactly the same.

Example​

❌ Bad:

void main() {
  final val = '1';

  // LINT: Both sides of this comparison are equal. Try checking it for a potential mistake.
  if (val == val) {
    return;
  }

  // LINT: Both sides of this comparison are equal. Try checking it for a potential mistake.
  if (val.length == val.length) {
    return;
  }

  // LINT: Both sides of this comparison are equal. Try checking it for a potential mistake.
  if (val > val) {
    return;
  }

  // LINT: Both sides of this comparison are equal. Try checking it for a potential mistake.
  if (val < val) {
    return;
  }
}

✅ Good:

void main() {
  final val = '1';
  final anotherVal = '2';

  if (val == anotherVal) { // Correct, another variable
    return;
  }

  if (val.length == anotherVal.length) {
    return;
  }

  if (val > anotherVal) {
    return;
  }

  if (val < anotherVal) {
    return;
  }
}

Additional Resources​