Why doesn't simple test pass using AutoFixture Freeze, SemanticComparison Likeness and CreateProxy?

autofixture, semantic-comparison

Solution

If you assign the values on the proxied instance (after calling the `CreateProxy` method) the test passes:

[Fact]
public void Equality_Behaves_As_Expected()
{
    // AutoMoqCustomization is not necessary.
    var original = new Fixture().Create<Band>();

    var likeness = original
        .AsSource()
        .OfLikeness<Band>()
        .Without(x => x.Brass)
        .CreateProxy();

    likeness.Brass = "foo"; // Ignored.
    likeness.Strings = original.Strings;

    Assert.True(likeness.Equals(original));
    likeness.Should().Be(original);
    likeness.ShouldBeEquivalentTo(original);
}

Keep in mind that `Likeness` creates a proxy on the target type and only that type's instance overrides `Equals`.

Since the source type remains intact, the following assertions will not succeed:

`Assert.True(original.Equals(likeness));` `original.Should().Be(likeness);` `original.ShouldBeEquivalentTo(likeness);`

Update

From version 3.0.4 and above the values are automatically copied to the proxy instance (which means, `likeness.Strings = original.Strings;` is going to happen automatically).

Problem

I'm trying to understand how to use the `CreateProxy()` feature of `Likeness<T>()` using two instances of a simple class. ``` public class Band { public string Strings { get; set; } public string Brass { get; set; } } ``` With the following test, I use a `Fixture` to `Create<T>` a `Band` instance with values for the two string properties. ``` [Fact] public void Equality_Behaves_As_Expected() { // arrange var fixture = new Fixture(); fixture.Customize(new AutoMoqCustomization()); var original = fixture.Create<Band>(); // Brass something like --> "Brass65756b89-d9f3-42f8-88fc-ab6de5ae65cd" // Strings something like --> "Strings7439fa1b-014d-4544-8428-baea66858940" // act var dupe = new Band {Brass = original.Brass, Strings = original.Strings}; // Brass same as original's like --> "Brass65756b89-d9f3-42f8-88fc-ab6de5ae65cd" // Strings same as original's like --> "Strings7439fa1b-014d-4544-8428-baea66858940" ``` I've tried many different assertions, but the crux of the matter seems to be that the `CreateProxy` method is not populating the properties of `Band`, so that even when I try to compare two instances of `Band` with the same property values, the instance from the `CreateProxy` method always has null values. ``` // assert var likeness = dupe.AsSource().OfLikeness<Band>() .Without(x => x.Brass).CreateProxy(); // Brass & String properties are null using dupe as source of likeness (!) //var likeness = original.AsSource().OfLikeness<Band>() // .Without(x => x.Brass).CreateProxy(); // Brass & String properties are null using original as source of likeness (!) //Assert.True(likeness.Equals(original)); // Fails //Assert.True(original.Equals(likeness)); // Fails // below are using FluentAssertions assembly //likeness.Should().Be(original); // Fails (null properties) //original.Should().Be(likeness); // Fails (null properties) //likeness.ShouldBeEquivalentTo(original); // Fails (null properties) //original.ShouldBeEquivalentTo(likeness); // Fails (null properties) } ``` I've gotta be doing something wrong, but I've read everything I can find on the Ploeh blog and SO, and can't find an example suitably simple enough to compare to what I'm doing. Any ideas?

Original source

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