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dennisdoomen merged 1 commit into from
Mar 30, 2020
Merged

Allows using an IEqualityComparer<T> with BeEquivalentTo #1284

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40 changes: 40 additions & 0 deletions Src/FluentAssertions/Equivalency/EqualityComparerEquivalencyStep.cs
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@@ -0,0 +1,40 @@
using System;
using System.Collections.Generic;
using FluentAssertions.Execution;

namespace FluentAssertions.Equivalency
{
public class EqualityComparerEquivalencyStep<T> : IEquivalencyStep
{
private readonly IEqualityComparer<T> comparer;

public EqualityComparerEquivalencyStep(IEqualityComparer<T> comparer)
{
this.comparer = comparer ?? throw new ArgumentNullException(nameof(comparer));
}

public bool CanHandle(IEquivalencyValidationContext context, IEquivalencyAssertionOptions config)
{
return config.GetExpectationType(context) == typeof(T);
}

public bool Handle(IEquivalencyValidationContext context, IEquivalencyValidator parent, IEquivalencyAssertionOptions config)
{
Execute.Assertion
.BecauseOf(context.Because, context.BecauseArgs)
.ForCondition(context.Subject is T)
.FailWith("Expected {context:object} to be of type {0}{because}, but found {1}", typeof(T), context.Subject)
.Then
.ForCondition(comparer.Equals((T)context.Subject, (T)context.Expectation))
.FailWith("Expected {context:object} to be equal to {1} according to {0}{because}, but {2} was not.",
comparer.ToString(), context.Expectation, context.Subject);

return true;
}

public override string ToString()
{
return $"Use {comparer} for objects of type {typeof(T)}";
}
}
}
21 changes: 21 additions & 0 deletions Src/FluentAssertions/Equivalency/SelfReferenceEquivalencyAssertionOptions.cs
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Expand Up @@ -422,6 +422,27 @@ public TSelf Using(IEquivalencyStep equivalencyStep)
return AddEquivalencyStep(equivalencyStep);
}

/// <summary>
/// Ensures the equivalency comparison will create and use an instance of <typeparamref name="TEqualityComparer"/>
/// that implements <see cref="IEqualityComparer{T}"/>, any time
/// when a property is of type <typeparamref name="T"/>.
/// </summary>
public TSelf Using<T, TEqualityComparer>() where TEqualityComparer : IEqualityComparer<T>, new()
{
return Using(new TEqualityComparer());
}

/// <summary>
/// Ensures the equivalency comparison will use the specified implementation of <see cref="IEqualityComparer{T}"/>
/// any time when a property is of type <typeparamref name="T"/>.
/// </summary>
public TSelf Using<T>(IEqualityComparer<T> comparer)
{
userEquivalencySteps.Insert(0, new EqualityComparerEquivalencyStep<T>(comparer));

return (TSelf)this;
}

/// <summary>
/// Causes all collections to be compared in the order in which the items appear in the expectation.
/// </summary>
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10 changes: 10 additions & 0 deletions Tests/Approval.Tests/ApprovedApi/FluentAssertions/net47.approved.txt
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Expand Up @@ -611,6 +611,13 @@ namespace FluentAssertions.Equivalency
public bool CanHandle(FluentAssertions.Equivalency.IEquivalencyValidationContext context, FluentAssertions.Equivalency.IEquivalencyAssertionOptions config) { }
public bool Handle(FluentAssertions.Equivalency.IEquivalencyValidationContext context, FluentAssertions.Equivalency.IEquivalencyValidator parent, FluentAssertions.Equivalency.IEquivalencyAssertionOptions config) { }
}
public class EqualityComparerEquivalencyStep<T> : FluentAssertions.Equivalency.IEquivalencyStep
{
public EqualityComparerEquivalencyStep(System.Collections.Generic.IEqualityComparer<T> comparer) { }
public bool CanHandle(FluentAssertions.Equivalency.IEquivalencyValidationContext context, FluentAssertions.Equivalency.IEquivalencyAssertionOptions config) { }
public bool Handle(FluentAssertions.Equivalency.IEquivalencyValidationContext context, FluentAssertions.Equivalency.IEquivalencyValidator parent, FluentAssertions.Equivalency.IEquivalencyAssertionOptions config) { }
public override string ToString() { }
}
public enum EqualityStrategy
{
Equals = 0,
Expand Down Expand Up @@ -811,6 +818,9 @@ namespace FluentAssertions.Equivalency
public TSelf Using(FluentAssertions.Equivalency.IMemberMatchingRule matchingRule) { }
public TSelf Using(FluentAssertions.Equivalency.IMemberSelectionRule selectionRule) { }
public FluentAssertions.Equivalency.SelfReferenceEquivalencyAssertionOptions<TSelf>.Restriction<TProperty> Using<TProperty>(System.Action<FluentAssertions.Equivalency.IAssertionContext<TProperty>> action) { }
public TSelf Using<T>(System.Collections.Generic.IEqualityComparer<T> comparer) { }
public TSelf Using<T, TEqualityComparer>()
where TEqualityComparer : System.Collections.Generic.IEqualityComparer<T>, new () { }
public TSelf WithAutoConversion() { }
public TSelf WithAutoConversionFor(System.Linq.Expressions.Expression<System.Func<FluentAssertions.Equivalency.IMemberInfo, bool>> predicate) { }
public TSelf WithStrictOrdering() { }
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10 changes: 10 additions & 0 deletions Tests/Approval.Tests/ApprovedApi/FluentAssertions/netcoreapp2.1.approved.txt
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Expand Up @@ -611,6 +611,13 @@ namespace FluentAssertions.Equivalency
public bool CanHandle(FluentAssertions.Equivalency.IEquivalencyValidationContext context, FluentAssertions.Equivalency.IEquivalencyAssertionOptions config) { }
public bool Handle(FluentAssertions.Equivalency.IEquivalencyValidationContext context, FluentAssertions.Equivalency.IEquivalencyValidator parent, FluentAssertions.Equivalency.IEquivalencyAssertionOptions config) { }
}
public class EqualityComparerEquivalencyStep<T> : FluentAssertions.Equivalency.IEquivalencyStep
{
public EqualityComparerEquivalencyStep(System.Collections.Generic.IEqualityComparer<T> comparer) { }
public bool CanHandle(FluentAssertions.Equivalency.IEquivalencyValidationContext context, FluentAssertions.Equivalency.IEquivalencyAssertionOptions config) { }
public bool Handle(FluentAssertions.Equivalency.IEquivalencyValidationContext context, FluentAssertions.Equivalency.IEquivalencyValidator parent, FluentAssertions.Equivalency.IEquivalencyAssertionOptions config) { }
public override string ToString() { }
}
public enum EqualityStrategy
{
Equals = 0,
Expand Down Expand Up @@ -811,6 +818,9 @@ namespace FluentAssertions.Equivalency
public TSelf Using(FluentAssertions.Equivalency.IMemberMatchingRule matchingRule) { }
public TSelf Using(FluentAssertions.Equivalency.IMemberSelectionRule selectionRule) { }
public FluentAssertions.Equivalency.SelfReferenceEquivalencyAssertionOptions<TSelf>.Restriction<TProperty> Using<TProperty>(System.Action<FluentAssertions.Equivalency.IAssertionContext<TProperty>> action) { }
public TSelf Using<T>(System.Collections.Generic.IEqualityComparer<T> comparer) { }
public TSelf Using<T, TEqualityComparer>()
where TEqualityComparer : System.Collections.Generic.IEqualityComparer<T>, new () { }
public TSelf WithAutoConversion() { }
public TSelf WithAutoConversionFor(System.Linq.Expressions.Expression<System.Func<FluentAssertions.Equivalency.IMemberInfo, bool>> predicate) { }
public TSelf WithStrictOrdering() { }
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10 changes: 10 additions & 0 deletions Tests/Approval.Tests/ApprovedApi/FluentAssertions/netcoreapp3.0.approved.txt
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Expand Up @@ -611,6 +611,13 @@ namespace FluentAssertions.Equivalency
public bool CanHandle(FluentAssertions.Equivalency.IEquivalencyValidationContext context, FluentAssertions.Equivalency.IEquivalencyAssertionOptions config) { }
public bool Handle(FluentAssertions.Equivalency.IEquivalencyValidationContext context, FluentAssertions.Equivalency.IEquivalencyValidator parent, FluentAssertions.Equivalency.IEquivalencyAssertionOptions config) { }
}
public class EqualityComparerEquivalencyStep<T> : FluentAssertions.Equivalency.IEquivalencyStep
{
public EqualityComparerEquivalencyStep(System.Collections.Generic.IEqualityComparer<T> comparer) { }
public bool CanHandle(FluentAssertions.Equivalency.IEquivalencyValidationContext context, FluentAssertions.Equivalency.IEquivalencyAssertionOptions config) { }
public bool Handle(FluentAssertions.Equivalency.IEquivalencyValidationContext context, FluentAssertions.Equivalency.IEquivalencyValidator parent, FluentAssertions.Equivalency.IEquivalencyAssertionOptions config) { }
public override string ToString() { }
}
public enum EqualityStrategy
{
Equals = 0,
Expand Down Expand Up @@ -811,6 +818,9 @@ namespace FluentAssertions.Equivalency
public TSelf Using(FluentAssertions.Equivalency.IMemberMatchingRule matchingRule) { }
public TSelf Using(FluentAssertions.Equivalency.IMemberSelectionRule selectionRule) { }
public FluentAssertions.Equivalency.SelfReferenceEquivalencyAssertionOptions<TSelf>.Restriction<TProperty> Using<TProperty>(System.Action<FluentAssertions.Equivalency.IAssertionContext<TProperty>> action) { }
public TSelf Using<T>(System.Collections.Generic.IEqualityComparer<T> comparer) { }
public TSelf Using<T, TEqualityComparer>()
where TEqualityComparer : System.Collections.Generic.IEqualityComparer<T>, new () { }
public TSelf WithAutoConversion() { }
public TSelf WithAutoConversionFor(System.Linq.Expressions.Expression<System.Func<FluentAssertions.Equivalency.IMemberInfo, bool>> predicate) { }
public TSelf WithStrictOrdering() { }
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10 changes: 10 additions & 0 deletions Tests/Approval.Tests/ApprovedApi/FluentAssertions/netstandard2.0.approved.txt
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Expand Up @@ -610,6 +610,13 @@ namespace FluentAssertions.Equivalency
public bool CanHandle(FluentAssertions.Equivalency.IEquivalencyValidationContext context, FluentAssertions.Equivalency.IEquivalencyAssertionOptions config) { }
public bool Handle(FluentAssertions.Equivalency.IEquivalencyValidationContext context, FluentAssertions.Equivalency.IEquivalencyValidator parent, FluentAssertions.Equivalency.IEquivalencyAssertionOptions config) { }
}
public class EqualityComparerEquivalencyStep<T> : FluentAssertions.Equivalency.IEquivalencyStep
{
public EqualityComparerEquivalencyStep(System.Collections.Generic.IEqualityComparer<T> comparer) { }
public bool CanHandle(FluentAssertions.Equivalency.IEquivalencyValidationContext context, FluentAssertions.Equivalency.IEquivalencyAssertionOptions config) { }
public bool Handle(FluentAssertions.Equivalency.IEquivalencyValidationContext context, FluentAssertions.Equivalency.IEquivalencyValidator parent, FluentAssertions.Equivalency.IEquivalencyAssertionOptions config) { }
public override string ToString() { }
}
public enum EqualityStrategy
{
Equals = 0,
Expand Down Expand Up @@ -810,6 +817,9 @@ namespace FluentAssertions.Equivalency
public TSelf Using(FluentAssertions.Equivalency.IMemberMatchingRule matchingRule) { }
public TSelf Using(FluentAssertions.Equivalency.IMemberSelectionRule selectionRule) { }
public FluentAssertions.Equivalency.SelfReferenceEquivalencyAssertionOptions<TSelf>.Restriction<TProperty> Using<TProperty>(System.Action<FluentAssertions.Equivalency.IAssertionContext<TProperty>> action) { }
public TSelf Using<T>(System.Collections.Generic.IEqualityComparer<T> comparer) { }
public TSelf Using<T, TEqualityComparer>()
where TEqualityComparer : System.Collections.Generic.IEqualityComparer<T>, new () { }
public TSelf WithAutoConversion() { }
public TSelf WithAutoConversionFor(System.Linq.Expressions.Expression<System.Func<FluentAssertions.Equivalency.IMemberInfo, bool>> predicate) { }
public TSelf WithStrictOrdering() { }
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10 changes: 10 additions & 0 deletions Tests/Approval.Tests/ApprovedApi/FluentAssertions/netstandard2.1.approved.txt
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Expand Up @@ -611,6 +611,13 @@ namespace FluentAssertions.Equivalency
public bool CanHandle(FluentAssertions.Equivalency.IEquivalencyValidationContext context, FluentAssertions.Equivalency.IEquivalencyAssertionOptions config) { }
public bool Handle(FluentAssertions.Equivalency.IEquivalencyValidationContext context, FluentAssertions.Equivalency.IEquivalencyValidator parent, FluentAssertions.Equivalency.IEquivalencyAssertionOptions config) { }
}
public class EqualityComparerEquivalencyStep<T> : FluentAssertions.Equivalency.IEquivalencyStep
{
public EqualityComparerEquivalencyStep(System.Collections.Generic.IEqualityComparer<T> comparer) { }
public bool CanHandle(FluentAssertions.Equivalency.IEquivalencyValidationContext context, FluentAssertions.Equivalency.IEquivalencyAssertionOptions config) { }
public bool Handle(FluentAssertions.Equivalency.IEquivalencyValidationContext context, FluentAssertions.Equivalency.IEquivalencyValidator parent, FluentAssertions.Equivalency.IEquivalencyAssertionOptions config) { }
public override string ToString() { }
}
public enum EqualityStrategy
{
Equals = 0,
Expand Down Expand Up @@ -811,6 +818,9 @@ namespace FluentAssertions.Equivalency
public TSelf Using(FluentAssertions.Equivalency.IMemberMatchingRule matchingRule) { }
public TSelf Using(FluentAssertions.Equivalency.IMemberSelectionRule selectionRule) { }
public FluentAssertions.Equivalency.SelfReferenceEquivalencyAssertionOptions<TSelf>.Restriction<TProperty> Using<TProperty>(System.Action<FluentAssertions.Equivalency.IAssertionContext<TProperty>> action) { }
public TSelf Using<T>(System.Collections.Generic.IEqualityComparer<T> comparer) { }
public TSelf Using<T, TEqualityComparer>()
where TEqualityComparer : System.Collections.Generic.IEqualityComparer<T>, new () { }
public TSelf WithAutoConversion() { }
public TSelf WithAutoConversionFor(System.Linq.Expressions.Expression<System.Func<FluentAssertions.Equivalency.IMemberInfo, bool>> predicate) { }
public TSelf WithStrictOrdering() { }
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179 changes: 179 additions & 0 deletions Tests/FluentAssertions.Specs/Equivalency/BasicEquivalencySpecs.cs
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Expand Up @@ -2237,6 +2237,185 @@ public void
act.Should().NotThrow();
}

[Fact]
public void When_a_nested_property_is_equal_based_on_equality_comparer_it_should_not_throw()
{
// Arrange
var subject = new
{
Timestamp = 22.March(2020).At(19, 30)
};

var expectation = new
{
Timestamp = 1.January(2020).At(7, 31)
};

// Act
Action act = () => subject.Should().BeEquivalentTo(expectation,
opt => opt.Using<DateTime, DateTimeByYearComparer>());


// Assert
act.Should().NotThrow();
}

[Fact]
public void When_a_nested_property_is_unequal_based_on_equality_comparer_it_should_throw()
{
// Arrange
var subject = new
{
Timestamp = 22.March(2020)
};

var expectation = new
{
Timestamp = 1.January(2021)
};

// Act
Action act = () => subject.Should().BeEquivalentTo(expectation,
opt => opt.Using(new DateTimeByYearComparer()));

// Assert
act.Should()
.Throw<XunitException>()
.WithMessage("Expected*equal*2021*DateTimeByYearComparer*2020*");
}

[Fact]
public void When_the_subjects_property_type_is_different_from_the_equality_comparer_it_should_throw()
{
// Arrange
var subject = new
{
Timestamp = 1L
};

var expectation = new
{
Timestamp = 1.January(2021)
};

// Act
Action act = () => subject.Should().BeEquivalentTo(expectation,
opt => opt.Using(new DateTimeByYearComparer()));

// Assert
act.Should()
.Throw<XunitException>()
.WithMessage("Expected*Timestamp*1L*");
}

private class DateTimeByYearComparer : IEqualityComparer<DateTime>
{
public bool Equals(DateTime x, DateTime y)
{
return x.Year == y.Year;
}

public int GetHashCode(DateTime obj) => obj.GetHashCode();
}

[Fact]
public void When_an_invalid_equality_comparer_is_provided_it_should_throw()
{
// Arrange
var subject = new
{
Timestamp = 22.March(2020)
};

var expectation = new
{
Timestamp = 1.January(2021)
};

IEqualityComparer<DateTime> equalityComparer = null;

// Act
Action act = () => subject.Should().BeEquivalentTo(expectation,
opt => opt.Using(equalityComparer));

// Assert
act.Should()
.Throw<ArgumentNullException>()
.WithMessage("*comparer*");
}

[Fact]
public void When_the_compile_time_type_does_not_match_the_equality_comparer_type_it_should_use_the_default_mechanics()
{
// Arrange
var subject = new
{
Property = (IInterface)new ConcreteClass("SomeString")
};

var expectation = new
{
Property = (IInterface)new ConcreteClass("SomeOtherString")
};

// Act
Action act = () => subject.Should().BeEquivalentTo(expectation, opt =>
opt.Using<ConcreteClass, ConcreteClassEqualityComparer>());

// Assert
act.Should().NotThrow();
}

[Fact]
public void When_the_runtime_type_does_match_the_equality_comparer_type_it_should_use_the_default_mechanics()
{
// Arrange
var subject = new
{
Property = (IInterface)new ConcreteClass("SomeString")
};

var expectation = new
{
Property = (IInterface)new ConcreteClass("SomeOtherString")
};

// Act
Action act = () => subject.Should().BeEquivalentTo(expectation, opt => opt
.RespectingRuntimeTypes()
.Using<ConcreteClass, ConcreteClassEqualityComparer>());

// Assert
act.Should().Throw<XunitException>().WithMessage("*ConcreteClassEqualityComparer*");
}

private interface IInterface
{

}

private class ConcreteClass : IInterface
{
private string property;

public ConcreteClass(string propertyValue)
{
property = propertyValue;
}

public string GetProperty() => property;
}

private class ConcreteClassEqualityComparer : IEqualityComparer<ConcreteClass>
{
public bool Equals(ConcreteClass x, ConcreteClass y)
{
return x.GetProperty().Equals(y.GetProperty());
}

public int GetHashCode(ConcreteClass obj) => obj.GetProperty().GetHashCode();
}

#endregion

#region Member Conversion
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1 change: 1 addition & 0 deletions docs/_pages/releases.md
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Expand Up @@ -16,6 +16,7 @@ sidebar:
* The `Using`/`When` option on `BeEquivalentTo` will now use the conversion rules when trying to match the predicate - [#1257](https://github.com/fluentassertions/fluentassertions/pull/1257).
* Added `NotBeWritable` to `PropertyInfoSelectorAssertions` to be able to assert that properties are not writable - [#1269](https://github.com/fluentassertions/fluentassertions/pull/1269).
* Added extension to assert `TaskCompletionSource<T>` - [#1267](https://github.com/fluentassertions/fluentassertions/pull/1267).
* Added the ability to pass an `IEqualityComparer<T>` through `BeEquivalentTo(x => x.Using<MyComparer>())` - [#1284](https://github.com/fluentassertions/fluentassertions/pull/1284).

**Fixes**
* Reported actual value when it contained `{{{{` or `}}}}` - [#1234](https://github.com/fluentassertions/fluentassertions/pull/1234).
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