This is the old Assert way:
Assert.That(contestant.Points, Is.EqualTo(1337));
For your troubles, you get this message, when it fails:
Expected 1337 but was 0
How it Should be:
contestant.Points.ShouldBe(1337);
Which is just syntax, so far, but check out the message when it fails:
contestant.Points should be 1337 but was 0
It might be easy to underestimate how useful this is. Another example, side by side:
Assert.That(map.IndexOfValue("boo"), Is.EqualTo(2)); // -> Expected 2 but was 1
map.IndexOfValue("boo").ShouldBe(2); // -> map.IndexOfValue("boo") should be 2 but was 1
Shouldly uses the variables within the ShouldBe statement to report on errors, which makes diagnosing easier.
Another example, if you compare two collections:
(new[] { 1, 2, 3 }).ShouldBe(new[] { 1, 2, 4 });
and it fails because they're different, it'll show you the differences between the two collections:
should be
[1, 2, 4]
but was
[1, 2, 3]
difference
[1, 2, *3*]
If you want to check that a particular call does/does not throw an exception, it's as simple as:
Should.Throw<ArgumentOutOfRangeException>(() => widget.Twist(-1));
Then if it chucks a wobbly, you have access to the exception to help debug what the underlying cause was.
Other Shouldly features:
####Equality
[ShouldBe] (#equalityShouldBeExample)
[ShouldBeOneOf] (#equalityShouldBeOneOfExample)
[ShouldNotBe] (#equalityShouldNotBeExample)
[ShouldNotBeOneOf] (#equalityShouldNotBeOneOfExample)
[ShouldBeGreaterThan(OrEqualTo)] (#equalityShouldBeGreaterThanExample)
[ShouldBeLessThan(OrEqualTo)] (#equalityShouldBeLessThanExample)
[ShouldBeOfType - Exact type match] (#equalityShouldBeOfTypeExample)
[ShouldBeAssignableTo] (#equalityShouldBeAssignableToExample)
[ShouldBeInRange] (#equalityShouldBeInRangeExample)
[ShouldNotBeInRange] (#equalityShouldNotBeInRangeExample)
####Enumerable
[ShouldBe(optional Tolerance/Ignore order)] (#enumerableShouldBeExample)
[ShouldAllBe(predicate)] (#enumerableShouldAllBeExample)
[ShouldContain] (#enumerableShouldContainExample)
[ShouldContain(predicate)] (#enumerableShouldContainExample)
[ShouldNotContain] (#enumerableShouldNotContainExample)
[ShouldNotContain(predicate)] (#enumerableShouldNotContainExample)
[ShouldBeEmpty] (#enumerableShouldBeEmptyExample)
[ShouldNotBeEmpty] (#enumerableShouldNotBeEmptyExample)
[ShouldBeOneOf(params)] (#enumerableShouldBeOneOfExample)
[ShouldBeSubsetOf] (#enumerableShouldBeSubsetOfExample)
####String
[ShouldStartWith] (#stringShouldStartWithExample)
[ShouldNotStartWith] (#stringShouldNotStartWithExample)
[ShouldEndWith] (#stringShouldEndWithExample)
[ShouldNotEndWith] (#stringShouldNotEndWithExample)
[ShouldContain] (#stringShouldContainExample)
[ShouldNotContain] (#stringShouldNotContainExample)
[ShouldContainWithoutWhitespace] (#stringShouldContainWithoutWhitespaceExample)
[ShouldMatch] (#stringShouldMatchExample)
[ShouldBeNullOrEmpty] (#stringShouldBeNullOrEmptyExample)
[ShouldNotBeNullOrEmpty] (#stringShouldNotBeNullOrEmptyExample)
####Dictionary
[ShouldContainKey] (#dictionaryShouldContainKeyExample)
[ShouldContainKeyAndValue] (#dictionaryShouldContainKeyAndValueExample)
[ShouldNotContainKey] (#dictionaryShouldNotContainKeyExample)
[ShouldNotContainValueForKey] (#dictionaryShouldNotContainValueForKeyExample)
####Exceptions
[Should.Throw(Action)] (#exceptionsShouldThrowActionExample)
[Should.NotThrow(Action)] (#exceptionsShouldNotThrowActionExample)
[Should.Throw(Func[, Timeout])] (#exceptionsShouldThrowFuncExample)
[Should.NotThrow(Func[, Timeout])] (#exceptionsShouldNotThrowFuncExample)
Task overloads for Should.Throw are blocking and will automatically timeout after 10 seconds (specified in ShouldlyConfiguration.DefaultTaskTimeout)
[CompleteIn] (#tasksCompleteInExample)
[ShouldHaveProperty] (#dynamicShouldHaveProperty)
All the example use the following classes.
namespace Simpsons
{
public abstract class Pet
{
public abstract string Name { get; set; }
}
}
namespace Simpsons
{
public class Cat : Pet
{
public override string Name { get; set; }
}
}
namespace Simpsons
{
public class Dog : Pet
{
public override string Name { get; set; }
}
}
namespace Simpsons
{
public class Person
{
public string Name { get; set; }
public int Salary { get; set; }
}
}Using the classes defined here, the following test ...
[Test]
public void ShouldBe()
{
var theSimpsonsCat = new Cat() { Name = "Santas little helper" };
theSimpsonsCat.Name.ShouldBe("Snowball 2");
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
theSimpsonsCat.Name
should be
"Snowball 2"
but was
"Santas little helper"
Using the classes defined here, the following test ...
[Test]
public void ShouldBeOneOf()
{
var apu = new Person() { Name = "Apu" };
var homer = new Person() { Name = "Homer" };
var skinner = new Person() { Name = "Skinner" };
var barney = new Person() { Name = "Barney" };
var theBeSharps = new List<Person>() { homer, skinner, barney };
apu.ShouldBeOneOf(theBeSharps.ToArray());
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
apu
should be one of
[Simpsons.Person, Simpsons.Person, Simpsons.Person]
but was
Simpsons.Person
Using the classes defined here, the following test ...
[Test]
public void ShouldNotBe()
{
var theSimpsonsCat = new Cat() { Name = "Santas little helper" };
theSimpsonsCat.Name.ShouldNotBe("Santas little helper");
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
theSimpsonsCat.Name
should not be
"Santas little helper"
but was
"Santas little helper"
Using the classes defined here, the following test ...
[Test]
public void ShouldNotBeOneOf()
{
var apu = new Person() { Name = "Apu" };
var homer = new Person() { Name = "Homer" };
var skinner = new Person() { Name = "Skinner" };
var barney = new Person() { Name = "Barney" };
var wiggum = new Person() { Name = "Wiggum" };
var theBeSharps = new List<Person>() { apu, homer, skinner, barney, wiggum };
wiggum.ShouldNotBeOneOf(theBeSharps.ToArray());
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
wiggum
should not be one of
[Simpsons.Person, Simpsons.Person, Simpsons.Person, Simpsons.Person, Simpsons.Person]
but was
Simpsons.Person
Using the classes defined here, the following tests ...
[Test]
public void ShouldBeGreaterThan_Example_1()
{
1.ShouldBeGreaterThan(2);
}
[Test]
public void ShouldBeGreaterThan_Example_2()
{
var mrBurns = new Person() { Name = "Mr. Burns", Salary = 30000 };
mrBurns.Salary.ShouldBeGreaterThan(300000000);
}... shows the following messages on failure ...
Shouldly.ChuckedAWobbly :
1
should be greater than
2
but was
1
Shouldly.ChuckedAWobbly :
mrBurns.Salary
should be greater than
300000000
but was
30000
Using the classes defined here, the following test ...
[Test]
public void ShouldBeLessThan()
{
var homer = new Person() { Name = "Homer", Salary = 300000000 };
homer.Salary.ShouldBeLessThan(30000);
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
homer.Salary
should be less than
30000
but was
300000000
Using the classes defined here, the following test ...
[Test]
public void ShouldBeOfType()
{
var theSimpsonsDog = new Cat() { Name = "Santas little helper" };
theSimpsonsDog.ShouldBeOfType<Dog>();
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
theSimpsonsDog
should be of type
Simpsons.Dog
but was
Simpsons.Cat
Using the classes defined here, the following test ...
[Test]
public void ShouldBeAssignableTo()
{
var theSimpsonsDog = new Person() { Name = "Santas little helper" };
theSimpsonsDog.ShouldBeAssignableTo<Pet>();
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
theSimpsonsDog
should be assignable to
Simpsons.Pet
but was
Simpsons.Person
Using the classes defined here, the following test ...
[Test]
public void ShouldBeInRange()
{
var homer = new Person() { Name = "Homer", Salary = 300000000 };
homer.Salary.ShouldBeInRange(30000, 40000);
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
homer.Salary
should be in range
{ from = 30000, to = 40000 }
but was
300000000
Using the classes defined here, the following test ...
[Test]
public void ShouldNotBeInRange()
{
var mrBurns = new Person() { Name = "Mr. Burns", Salary = 30000 };
mrBurns.Salary.ShouldNotBeInRange(30000, 40000);
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
mrBurns.Salary
should not be in range
{ from = 30000, to = 40000 }
but was
30000
Using the classes defined here, the following test ...
[Test]
public void IEnumerable_ShouldBe()
{
var apu = new Person() { Name = "Apu" };
var homer = new Person() { Name = "Homer" };
var skinner = new Person() { Name = "Skinner" };
var barney = new Person() { Name = "Barney" };
var theBeSharps = new List<Person>() { homer, skinner, barney };
theBeSharps.ShouldBe(new[] {apu, homer, skinner, barney});
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
theBeSharps
should be
[Simpsons.Person, Simpsons.Person, Simpsons.Person, Simpsons.Person]
but was
[Simpsons.Person, Simpsons.Person, Simpsons.Person]
difference
[*Simpsons.Person*, *Simpsons.Person*, *Simpsons.Person*, *]
Using the classes defined here, the following test ...
[Test]
public void IEnumerable_ShouldAllBe_Predicate()
{
var mrBurns = new Person() { Name = "Mr.Burns", Salary=3000000};
var kentBrockman = new Person() { Name = "Homer", Salary = 3000000};
var homer = new Person() { Name = "Homer", Salary = 30000};
var millionares = new List<Person>() {mrBurns, kentBrockman, homer};
millionares.ShouldAllBe(m => m.Salary > 1000000);
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
millionares
should all be an element satisfying the condition
(m.Salary > 1000000)
but does not
Using the classes defined here, the following test ...
[Test]
public void IEnumerable_ShouldContain()
{
var mrBurns = new Person() { Name = "Mr.Burns", Salary=3000000};
var kentBrockman = new Person() { Name = "Homer", Salary = 3000000};
var homer = new Person() { Name = "Homer", Salary = 30000};
var millionares = new List<Person>() {kentBrockman, homer};
millionares.ShouldContain(mrBurns);
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
millionares
should contain
Simpsons.Person
but was
[Simpsons.Person, Simpsons.Person]
Using the classes defined here, the following test ...
[Test]
public void IEnumerable_ShouldContain_Predicate()
{
var homer = new Person() { Name = "Homer", Salary = 30000};
var moe = new Person() { Name = "Moe", Salary=20000};
var barney = new Person() { Name = "Barney", Salary = 0};
var millionares = new List<Person>() {homer, moe, barney};
// Check if at least one element in the IEnumerable satisfies the predicate
millionares.ShouldContain(m => m.Salary > 1000000);
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
millionares
should contain an element satisfying the condition
(m.Salary > 1000000)
but does not
Using the classes defined here, the following test ...
[Test]
public void IEnumerable_ShouldNotContain()
{
var homerSimpson = new Person() { Name = "Homer"};
var homerGlumplich = new Person() { Name = "Homer"};
var lenny = new Person() { Name = "Lenny"};
var carl = new Person() { Name = "carl"};
var clubOfNoHomers = new List<Person>() {homerSimpson, homerGlumplich, lenny, carl };
clubOfNoHomers.ShouldNotContain(homerSimpson);
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
clubOfNoHomers
should not contain
Simpsons.Person
but was
[Simpsons.Person, Simpsons.Person, Simpsons.Person, Simpsons.Person]
Using the classes defined here, the following test ...
[Test]
public void IEnumerable_ShouldNotContain_Predicate()
{
var mrBurns = new Person() { Name = "Mr.Burns", Salary=3000000};
var kentBrockman = new Person() { Name = "Homer", Salary = 3000000};
var homer = new Person() { Name = "Homer", Salary = 30000};
var millionares = new List<Person>() {mrBurns, kentBrockman, homer};
millionares.ShouldNotContain(m => m.Salary < 1000000);
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
millionares
should not contain an element satisfying the condition
(m.Salary < 1000000)
but does
Using the classes defined here, the following test ...
[Test]
public void IEnumerable_ShouldBeEmpty()
{
var homer = new Person() { Name = "Homer"};
var powerPlantOnTheWeekend = new List<Person>() {homer};
powerPlantOnTheWeekend.ShouldBeEmpty();
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
powerPlantOnTheWeekend
should be empty
but was [Simpsons.Person]
Using the classes defined here, the following test ...
[Test]
public void IEnumerable_ShouldNotBeEmpty()
{
var moesTavernOnTheWeekend = new List<Person>() {};
moesTavernOnTheWeekend.ShouldNotBeEmpty();
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
moesTavernOnTheWeekend
should not be empty
but was
Using the classes defined here, the following test ...
[Test]
public void IEnumerable_ShouldBeOneOf()
{
var moe = new Person() { Name = "Moe"};
var lenny = new Person() { Name = "Lenny"};
var carl = new Person() { Name = "carl"};
var stoneCutters = new List<Person>() { moe, lenny, carl };
var clubOfNoHomers = new List<Person>() { moe, lenny, carl };
stoneCutters.ShouldBeOneOf(clubOfNoHomers);
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
stoneCutters
should be one of
[[Simpsons.Person, Simpsons.Person, Simpsons.Person]]
but was
[Simpsons.Person, Simpsons.Person, Simpsons.Person]
difference
[*Simpsons.Person*, *Simpsons.Person*, *Simpsons.Person*]
Using the classes defined here, the following test ...
[Test]
public void IEnumerable_ShouldBeSubsetOf()
{
var lisa = new Person() { Name = "Lisa"};
var bart = new Person() { Name = "Bart"};
var maggie = new Person() { Name = "Maggie"};
var homer = new Person() { Name = "Homer"};
var marge = new Person() { Name = "Marge"};
var ralph = new Person() { Name = "Ralph"};
var simpsonsKids = new List<Person>() { bart, lisa, maggie, ralph };
var simpsonsFamily = new List<Person>() {lisa, bart, maggie, homer, marge};
simpsonsKids.ShouldBeSubsetOf(simpsonsFamily);
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
simpsonsKids
should be subset of
[Simpsons.Person, Simpsons.Person, Simpsons.Person, Simpsons.Person, Simpsons.Person]
but does not
Using the classes defined here, the following test ...
[Test]
public void ShouldStartWith()
{
var lenny = new Person() { Name = "Carl"};
lenny.Name.ShouldStartWith("Len");
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
lenny.Name
should start with
"Len"
but was
"Carl"
Using the classes defined here, the following test ...
[Test]
public void ShouldNotStartWith()
{
var lenny = new Person() { Name = "Carl"};
lenny.Name.ShouldNotStartWith("Car");
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
lenny.Name
should not start with
"Car"
but was
"Carl"
Using the classes defined here, the following test ...
[Test]
public void ShouldEndWith()
{
var lenny = new Person() { Name = "Carl"};
lenny.Name.ShouldEndWith("nny");
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
lenny.Name
should end with
"nny"
but was
"Carl"
Using the classes defined here, the following test ...
[Test]
public void ShouldNotEndWith()
{
var lenny = new Person() { Name = "Carl"};
lenny.Name.ShouldNotEndWith("arl");
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
lenny.Name
should not end with
"arl"
but was
"Carl"
Using the classes defined here, the following test ...
[Test]
public void ShouldContain()
{
var lenny = new Person() { Name = "Carl"};
lenny.Name.ShouldContain("enn");
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
lenny.Name
should contain
"enn"
but was
"Carl"
Using the classes defined here, the following test ...
[Test]
public void ShouldNotContain()
{
var lenny = new Person() { Name = "Carl"};
lenny.Name.ShouldNotContain("ar");
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
lenny.Name
should not contain
"ar"
but was
"Carl"
Using the classes defined here, the following test ...
[Test]
public void ShouldContainWithoutWhitespace()
{
var simpsonDog = new Dog() { Name = "SantasLittleHelperS"};
simpsonDog.Name.ShouldContainWithoutWhitespace("Santas Little Helper");
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
simpsonDog.Name
should contain without whitespace
"Santas Little Helper"
but was
"SantasLittleHelperS"
Using the classes defined here, the following test ...
[Test]
public void ShouldMatch()
{
var simpsonDog = new Dog() { Name = "Santas little helper" };
simpsonDog.Name.ShouldMatch("Santas Little Helper");
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
simpsonDog.Name
should match
"Santas Little Helper"
but was
"Santas little helper"
Using the classes defined here, the following test ...
[Test]
public void ShouldBeNullOrEmpty()
{
var anonymousClanOfSlackJawedTroglodytes = new Person() {Name = "The Simpsons"};
anonymousClanOfSlackJawedTroglodytes.Name.ShouldBeNullOrEmpty();
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
anonymousClanOfSlackJawedTroglodytes.Name
should be null or empty
Using the classes defined here, the following test ...
[Test]
public void ShouldNotBeNullOrEmpty()
{
var troyMcClure = new Person() {};
troyMcClure.Name.ShouldNotBeNullOrEmpty();
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
troyMcClure.Name
should not be null or empty
Using the classes defined here, the following test ...
[Test]
public void ShouldContainKey()
{
var websters = new Dictionary<string, string>();
websters.Add("Embiggen", "To empower or embolden.");
websters.ShouldContainKey("Cromulent");
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
Dictionary
"websters"
should contain key
"Cromulent"
but does not
Using the classes defined here, the following test ...
[Test]
public void ShouldContainKeyAndValue()
{
var websters = new Dictionary<string, string>();
websters.Add("Cromulent", "I never heard the word before moving to Springfield.");
websters.ShouldContainKeyAndValue("Cromulent", "Fine, acceptable.");
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
Dictionary
"websters"
should contain key
"Cromulent"
with value
"Fine, acceptable."
but value was "I never heard the word before moving to Springfield."
Using the classes defined here, the following test ...
[Test]
public void ShouldNotContainKey()
{
var websters = new Dictionary<string, string>();
websters.Add("Chazzwazzers", "What Australians would have called a bull frog.");
websters.ShouldNotContainKey("Chazzwazzers");
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
Dictionary
"websters"
should not contain key
"Chazzwazzers"
but does
Using the classes defined here, the following test ...
[Test]
public void ShouldNotContainValueForKey()
{
var websters = new Dictionary<string, string>();
websters.Add("Chazzwazzers", "What Australians would have called a bull frog.");
websters.ShouldNotContainValueForKey("Chazzwazzers", "What Australians would have called a bull frog.");
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
Dictionary
"websters"
should not contain key
"Chazzwazzers"
with value
"What Australians would have called a bull frog."
but does
Using the classes defined here, the following test ...
[Test]
public void ShouldThrow()
{
var homer = new Person() { Name = "Homer", Salary = 30000};
var denominator = 1;
Should.Throw<DivideByZeroException>(() => {
var y = homer.Salary/denominator;
});
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
Should
throw
System.DivideByZeroException
but does not
Using the classes defined here, the following test ...
[Test]
public void ShouldNotThrow()
{
var homer = new Person() { Name = "Homer", Salary = 30000};
var denominator = 0;
Should.NotThrow(() => {
var y = homer.Salary/denominator;
});
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
Should
not throw
System.DivideByZeroException
but does
Using the classes defined here, the following test ...
[Test]
public void ShouldThrowFuncOfTask()
{
var homer = new Person() { Name = "Homer", Salary = 30000};
var denominator = 1;
Should.Throw<DivideByZeroException>(() =>
{
var task = Task.Factory.StartNew(() => { var y = homer.Salary/denominator; });
return task;
});
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
Should
throw
System.DivideByZeroException
but does not
Using the classes defined here, the following test ...
[Test]
public void ShouldNotThrowFuncOfTask()
{
var homer = new Person() { Name = "Homer", Salary = 30000};
var denominator = 0;
Should.NotThrow(() =>
{
var task = Task.Factory.StartNew(() => { var y = homer.Salary/denominator; });
return task;
});
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
Should
not throw
System.DivideByZeroException
but does
Using the classes defined here, the following test ...
// NOTE: Currently not in the latest Nuget version of Shouldly (version - 2.1.1 )
[Test]
public void CompleteIn()
{
var homer = new Person() { Name = "Homer", Salary = 30000 };
var denominator = 1;
Should.CompleteIn(() =>
{
Thread.Sleep(2000);
var y = homer.Salary / denominator;
}, TimeSpan.FromSeconds(1));
}... shows the following message on failure ...
System.TimeoutException : The operation has timed out.
Using the classes defined here, the following test ...
// NOTE: Currently not in the latest Nuget version of Shouldly (version - 2.1.1 )
[Test]
public void DynamicShouldHavePropertyTest()
{
var homerThinkingLikeFlanders = new ExpandoObject();
DynamicShould.HaveProperty(homerThinkingLikeFlanders, "IAmABigFourEyedLameO");
}... shows the following message on failure ...
Shouldly.ChuckedAWobbly :
Dynamic Object
"homerThinkingLikeFlanders"
should contain property
"IAmABigFourEyedLameO"
but does not.