Numeric Testing

server_testing provides comprehensive numeric testing capabilities through extensions and assertions on AssertableJson.

Basic Numeric Assertions

response.assertJson((json) {
  json
    // Basic comparisons
    .isGreaterThan('age', 18)
    .isLessThan('price', 100)
    .isGreaterOrEqual('quantity', 1)
    .isLessOrEqual('discount', 50)
    
    // Range testing
    .isBetween('score', 0, 100)
    
    // Mathematical checks
    .isDivisibleBy('quantity', 5)
    .isMultipleOf('price', 10)
    .isPerfectSquare('area')  // e.g., 16, 25, 36
    
    // Sign testing
    .isPositive('balance')
    .isNegative('debt')
    .isZero('count')
    
    // Number properties
    .isEven('evenNumber')
    .isOdd('oddNumber')
    .isPrime('primeNumber')  // Tests if number is prime
});

Mathematical Functions

response.assertJson((json) {
  json
    // Square root
    .where('sqrt', (value) => value.sqrt() == 5)  // value = 25
    
    // Power
    .where('squared', (value) => value.pow(2) == 25)  // value = 5
    
    // Custom calculations
    .where('total', (value) {
      final number = value as num;
      return number.isGreaterThan(100) && 
             number.isDivisibleBy(10);
    });
});

Array Operations

response.assertJson((json) {
  json
    // Array length
    .count('items', 5)
    .countBetween('items', 1, 10)
    
    // Array items
    .scope('numbers', (numbers) {
      numbers.each((num) {
        num
          .isGreaterThan(0)
          .isLessThan(100)
          .isDivisibleBy(5);
      });
    });
});

Numeric Validation in Schema

response.assertJson((json) {
  json.matchesSchema({
    'id': int,
    'score': double,
    'metrics': {
      'count': int,
      'average': double,
      'values': List<num>
    }
  });
});

Error Margins

response.assertJson((json) {
  json
    // Approximate equality
    .where('pi', (value) => (value - 3.14159).abs() < 0.00001)
    
    // Range checks with tolerance
    .where('temperature', (value) {
      final temp = value as num;
      return temp.isBetween(36.5, 37.5);
    });
});

Conditional Testing

response.assertJson((json) {
  json
    // Test conditionally
    .when(isPremiumUser, (json) {
      json
        .isGreaterThan('credits', 1000)
        .isPositive('bonus');
    })
    
    // Test numeric ranges
    .where('score', (value) {
      final score = value as num;
      if (isDifficultMode) {
        return score.isBetween(80, 100);
      } else {
        return score.isBetween(60, 100);
      }
    });
});