Numeric Extensions

server_testing provides powerful numeric extensions for both conditions and assertions when testing numeric values with AssertableJson.

Numeric Conditions

The NumericConditions extension provides boolean methods for checking numeric properties:

void main() {
  final number = 25;
  
  // Comparison operations
  print(number.isGreaterThan(20));     // true
  print(number.isLessThan(30));        // true
  print(number.isGreaterOrEqual(25));  // true
  print(number.isLessOrEqual(25));     // true
  print(number.isBetween(20, 30));     // true
  
  // Mathematical checks
  print(number.isDivisibleBy(5));      // true
  print(number.isMultipleOf(5));       // true
  print(number.isPerfectSquare());     // true (5 * 5 = 25)
  
  // Sign checks
  print(number.isPositive());          // true
  print(number.isNegative());          // false
  print(number.isZero());             // false
  
  // Number properties
  print(number.isEven());             // false
  print(number.isOdd());              // true
  print(number.isPrime());            // false
  
  // Mathematical operations
  print(number.sqrt());               // 5.0
  print(number.pow(2));               // 625
}

Numeric Assertions

For testing, use the NumericAssertions extension to assert numeric conditions:

void main() {
  test('numeric validations', () {
    final number = 25;
    
    // Basic assertions
    number.assertGreaterThan(20);
    number.assertLessThan(30);
    number.assertGreaterOrEqual(25);
    number.assertLessOrEqual(25);
    
    // Range assertions
    number.assertBetween(20, 30);
    
    // Mathematical assertions
    number.assertDivisibleBy(5);
    number.assertMultipleOf(5);
    number.assertPerfectSquare();
    
    // Sign assertions
    number.assertPositive();
    
    // Properties
    number.assertOdd();
  });
}

Custom Error Messages

You can provide custom error messages for assertions:

test('custom errors', () {
  final age = 15;
  
  // Custom error message
  age.assertGreaterThan(
    18,
    message: 'Age must be at least 18 years'
  );
  
  // Default message would be:
  // "Expected 15 to be greater than 18"
});

Chaining Assertions

Assertions can be chained using cascade notation:

test('chained assertions', () {
  final number = 25;
  
  number
    ..assertGreaterThan(0)
    ..assertLessThan(100)
    ..assertDivisibleBy(5)
    ..assertOdd()
    ..assertPerfectSquare();
});

Prime Number Testing

Built-in prime number validation:

test('prime numbers', () {
  // Check if numbers are prime
  17.assertPrime();
  23.assertPrime();
  
  // Will fail for non-prime numbers
  expect(
    () => 25.assertPrime(),
    throwsA(isA<TestFailure>())
  );
  
  // Prime conditions
  expect(17.isPrime(), isTrue);
  expect(25.isPrime(), isFalse);
});