Hi,
The library hasn't been designed for that, but the actual exception class that is thrown upon a verification failure was designed to be pluggable. Unfortunately, the AssertionHelper class is internal. You could file a change request or fork the repository and create a pull request that we could incorporate in the library.
lets say i have the following xml
<contacts><contact><name>Bob</name><addresspostalAddress="true"><street>123 Smith st</street><address></contact></contacts>
How do i assert that the content of the Street element is "123 Smith st"?
I have a couple of object graph comparison cases that I'm struggling to set up with the Fluent Assertions library. Both involve some level of advanced mapping from an object (and Entity Framework entity in this case) to its corresponding DTO.
Case 1: Using the documentation's example of Order and OrderDto, let's say that Product as an associated Manufacturer with a Name property (o.Product.Manufacturer.Name). The ProductDto, though, just has a ManufacturerName property on it instead of an associated ManufacturerDto (i.e. dto.Product.ManufacturerName = o.Product.Manufacturer.Name).
Case 2: Assume that CustomerDto has a name property on it. The underlying Customer object, though, is split into a FirstName and LastName that are combined when creating the DTO (i.e. dto.Customer.Name = o.Customer.FirstName + " " + o.Customer.LastName).
It looks like these cases can be handled by creating appropriate IMatchingRule and IAssertionRule classes and plugging them in with the Using() method. Is there some more (for lack of a better word) "fluent" way to do this? Something like:
orderDto.ShouldBeEquivalentTo(order,
opt => opt
.MappingProperty(dto => dto.Product.ManufacturerName).ToProperty(o => o.Product.Manufacturer.Name)
.MappingProperty(dto => dto.Customer.Name).ToValue(o => o.Customer.FirstName + " "+ o.Customer.LastName));Or maybe:
orderDto.ShouldBeEquivalentTo(order,
opt => opt
.WhereProperty(dto => dto.Product.ManufacturerName, (val, o) => val.Should().Be(o.Product.Manufacturer.Name))
.WhereProperty(dto => dto.Customer.Name, (val, o) => val.Should().Be(o => o.Customer.FirstName + " "+ o.Customer.LastName)));I may have just missed something obvious, so I figured I would ask before I start writing extensions or forking and hacking.
Many thanks for the library. I wish I had discovered it a year ago.
Hi leoghann,
Thanks for taking the time to properly formulate your question. What you might want to do is use theUsing-When methods of the options object. The EquivalencySpecs you'll find some examples like these:
Action act = () => subject.ShouldBeEquivalentTo(expectation, options => options
.Using<DateTime>(ctx => ctx.Subject.Should().BeCloseTo(ctx.Expectation, 1000))
.When(info => info.PropertyPath.EndsWith("Date")));or
Action act = () => subject.ShouldBeEquivalentTo(expectation, options =>
options
.Using<DateTime>(ctx => ctx.Subject.Should().BeCloseTo(ctx.Expectation, 1000))
.WhenTypeIs<DateTime>());If you really want to make it fluent, I would rewrite your example as
orderDto.ShouldBeEquivalentTo(order,
opt => opt
.Where(dto => dto.Product.ManufacturerName).ShouldMapTo(o => o.Product.Manufacturer.Name)
.Where(dto => dto.Customer.Name).ShouldHaveValue(o => o.Customer.FirstName + " " + o.Customer.LastName));Hi nitro52,
Sorry for the delayed response. Unfortunately, it is not yet possible to verify the contents of a particular element. As an alternative, you could do something similar by finding the XElement that represents its state and invoke an ordinary string assertion streetElement.Value.Should().Be("123 Smith st");
Regards,
Dennis
You can provide some context about the subject-under-test you are asserting by setting the static Verification.SubjectName property. However, you must make sure you set that property to null to prevent influencing another assertion. To actually change the 'object' into something more specific a code change is required.
Let me know what you think...
Dennis
Don't worry about that. As long as you're a happy user ;-)
I did see the Using-When examples. For a single object, it looks I could do something like this:
orderDto.ShouldBeEquivalentTo(order, options =>
options
.Using<string>(ctx => ctx.Subject.Should.Be(order.Product.Manufacturer.Name))
.When(info => info.PropertyPath.EndsWith("ManufacturerName")));
I have cases, though, where I'm going to be comparing collections of objects. That left me trying to figure out how to get to the individual objects being compared during a ShouldAllBeEquivalentTo call. Having looked at it again, though, it looks like I could just manually iterate the collections and use something like the above example to compare them.
for (var i = 0; i < results.Count; i++) { orderDtos[i].ShouldBeEquivalentTo(orders[i], options => options /* Using-When code here */); }
(I'd need to compare the counts of the two collections as well, but for some reason the code editor keeps having problems when I try to put in ShouldHaveCount.)
Edit: That doesn't seem to work like I thought it would. If I try to run it as written, I get an exception that subject has a property the other object doesn't have. If I add in .ExcludeMissingProperties() the test gives a false success.
I have a class, let's call it Foo, that is a value type and hence overrides the Equals/GetHashCode() methods. In a separate test fixture, I want to assert thatall the properties on Foo have been set properly, not just the properties used for equality. For this reason, my test assertion specifically uses the ShouldBeEquivalentTo method, which the documentation suggests will consider two objects to be equivalent if "both object graphs have equally named properties with the same value, irrespective of the type of those objects."
However, it appears that ShouldBeEquivalentTo invokes Foo.Equals method, gets a true result and then proceeds to short-circuit the reflection based property matching that ShouldBeEquivalentTo promises.
Is this expected behavior? If so, in inspecting the FA source, I saw no easy way to alter this behavior (IEquivalencyStep is declared internal). Are there any other ways to alter this behaviour?
I'm trying to use FluentAssertions together with SpecFlow.
And I want to be able to have statements which say:
the <propertyName> should have <value>
As such I want to compare 2 objects to make sure they have matching properties where the propertyName is specified using a string.
Is this possible?