The Fluent Assertions library written in Dart.

It uses Dart's Extension Functions to provide a fluent wrapper around test assertions.

Usage

Basic Assertions

These assertions are available for all objects.

Equality

'Hello'.shouldBeEqualTo('Hello');

'Hello'.shouldNotBeEqualTo('Word');

Reference equality

final me = Person(name: 'Karol');
final someoneElse = Person(name: 'Karol');
me.shouldBe(me);
me.shouldNotBe(someoneElse);

Subtypes

const num numberOfGirlsIAttract = 0;
numberOfGirlsIAttract.shouldBeInstanceOf<int>();
numberOfGirlsIAttract.shouldNotBeInstanceOf<double>();

Nullability

const hello = 'Hello';
hello.shouldNotBeNull();

const hello = null;
hello.shouldBeNull();

Booleans

const hasChildren = true;
hasChildren.shouldBeTrue();
hasChildren.shouldNotBeFalse();

const hasChildren = false;
hasChildren.shouldBeFalse();
hasChildren.shouldNotBeTrue();

Numerical Assertions

2.shouldBeGreaterOrEqualTo(2);

2.shouldBeGreaterThan(1);

2.shouldBeLessOrEqualTo(2);

1.shouldBeLessThan(2);

1.shouldBePositive();
1.shouldNotBeNegative();

(-1).shouldBeNegative();
(-1).shouldNotBePositive();

0.shouldBeZero();
1.shouldNotBeZero();

0.999.shouldBeNear(1, delta: 0.01);

0.shouldNotBeInRange(lowerBound: 1, upperBound: 6);
1.shouldBeInRange(lowerBound: 1, upperBound: 6);

String Assertions

'Flutter'.shouldBeEqualToIgnoringCase('FLUTTER');
'Flutter'.shouldNotBeEqualToIgnoringCase('Xamarin');

'Flutter rules'.shouldStartWith('Flutter');
'Flutter rules'.shouldNotStartWith('Xamarin');

'Flutter rules'.shouldStartWithIgnoringCase('FLUTTER');
'Flutter rules'.shouldNotStartWithIgnoringCase('Xamarin');

'I love Flutter'.shouldEndWith('Flutter');
'I love Flutter'.shouldNotEndWith('Xamarin');

'I love Flutter'.shouldEndWithIgnoringCase('flutter');
'I love Flutter'.shouldNotEndWithIgnoringCase('xamarin');

'I love Flutter'.shouldContain('love');
'I love Flutter'.shouldNotContain('hate');

'I love Flutter'.shouldContainIgnoringCase('LOVE');
'I love Flutter'.shouldNotContainIgnoringCase('HATE');

'I love Flutter'.shouldContainAll(['Flutter', 'love']);
'I love Flutter'.shouldContainAllIgnoringCase(['flutter', 'love']);

'I love Flutter'.shouldContainAllInOrder(['love', 'Flutter']);
'I love Flutter'.shouldContainAllInOrderIgnoringCase(['Love', 'Flutter']);

'12345'.shouldMatch(r'\d');
'Hello'.shouldNotMatch(r'\d');

''.shouldBeEmpty()
'name'.shouldNotBeEmpty()

''.shouldBeNullOrEmpty()
'name'.shouldNotBeNullOrEmpty()

' '.shouldBeBlank()
'name'.shouldNotBeBlank()

' '.shouldBeNullOrBlank()
'name'.shouldNotBeNullOrBlank()

Iterable Assertions

['Flutter', 'React Native', 'Jetpack Compose'].shouldContain('Flutter');
['Flutter', 'React Native', 'Jetpack Compose'].shouldContainIgnoringCase('flutter');

['Flutter', 'React Native', 'Jetpack Compose'].shouldNotContain('Vue');
['Flutter', 'React Native', 'Jetpack Compose'].shouldNotContainIgnoringCase('vue');

['Flutter', 'React Native', 'Jetpack Compose'].shouldContainAny(['Flutter', 'Vue']);
['Flutter', 'React Native', 'Jetpack Compose'].shouldContainAnyIgnoringCase(['react native']);

['Flutter', 'React Native', 'Jetpack Compose'].shouldContainNone(['Angular', 'Vue'])
['Flutter', 'React Native', 'Jetpack Compose'].shouldContainNoneIgnoringCase(['angular', 'vue']);

['Flutter', 'React Native', 'Jetpack Compose'].shouldContainAll(['Jetpack Compose', 'React Native']);
['Flutter', 'React Native', 'Jetpack Compose'].shouldContainAllIgnoringCase(['jetpack compose', 'react native']);

['Flutter', 'React Native', 'Jetpack Compose'].shouldContainAllInOrder(['Flutter', 'React Native']);
['Flutter', 'React Native', 'Jetpack Compose'].shouldContainAllInOrderIgnoringCase(['flutter', 'react native']);

['Flutter', 'React Native', 'Jetpack Compose'].shouldContainAllThat((framework) => framework.startsWith(RegExp('[A-Z]')));
['Flutter', 'React Native', 'Jetpack Compose'].shouldContainAnyThat((framework) => framework.contains('React'));
['Flutter', 'React Native', 'Jetpack Compose'].shouldContainNoneThat((framework) => framework.isEmpty);

Features and bugs

Please file feature requests and bugs at the issue tracker.

Author

• Karol Lisiewicz