assertNegative method

void assertNegative({
  1. String? message,
})

Asserts that this number is negative (less than zero).

Throws a test failure if this number is not negative.

Example:

(-5).assertNegative(); // Passes
0.assertNegative();    // Fails
5.assertNegative();    // Fails
  • message: Optional custom message for the failure reason.

Implementation

void assertNegative({String? message}) {
  expect(this < 0, isTrue,
      reason: message ?? 'Expected $this to be negative');
}