fluentassert | Extensible fluent API for assertions | Assertion library

As suggested by @canton7, after reviewing the 'Call Stack' and 'Breakpoint' windows, I found there was a breakpoint on a non-existent file called 'TestClass.cs'. Deleting all breakpoints fixed this issue.

The short answer is - Yes, AutoFixture can help you reduce the boilerplate and keep your tests DRY. Below is what you tests could potentially look like with AutoFixture. For more details on using AutoFixture, you can visit the documentation, check out the Pluralsight course, read about AutoFixture on Mark Seeman's blog, or seek help on AutoFixture's GitHub Q&A section.

To put it simply, you end up with a different mock instance for the Int2 property, after you set the return value for the Prop1 property. To fulfill your request Moq will generate a new mock, that will return the expected value for Prop1.

You can look at it as being equivalent to the following test:

If you want to directly access the extension method on a double object, and not on a DoubleAssertion object, why introduce the complexity of even creating a new type DoubleAssertion. Instead, define an extension method directly for NumericAssertions.

Have you tried using the options.ComparingByMembers

Try changing your test to be: partnerDto.Address.Should().BeEquivalentTo(partner.Address, o => o.ComparingByMembers

You are using the SpecFlow+ Runner, which per default uses process isolation for separating the threads. Because of this, the working directory is not the output directory.

You have two options:

1. Getting the folder via API from SpecFlow+ Runner

We have an API to get the output folder. Get an instance of TestRunContext via context injection and use the TestDirectory property (https://docs.specflow.org/projects/specflow-runner/en/latest/Usage/SpecFlow-Runner-APIs.html#string-testdirectory-get).

1. Switch to shared appdomain

I would only do this, if you don't need an isolation between your test threads.

Put in your Default.srProfile this

You mention that it only works in Debug mode and only when the expression is written in a single line. Indeed exception stacktraces in Debug mode contain the full path to the source file and the line number of every stack frame leading up to the place where the exception occurred.

The library can therefore read that line from the file and examine it. It might do a full expression parse of the line, but it’s more likely they went for the quick-and-dirty route of using regular expressions. All it really needs to do in all of the examples you quoted is to remove .Should() and everything after it.

In your position I would modify the source files slightly (e.g. vary the spacing and/or add some /* comments */ in the middle of the line) to see if the exception message retains those. If it does, we know that it reads from the source file. If it doesn’t, I’m willing to bet that it still reads from the source file but performs a syntactic parse of the relevant line and reconstructs it.

Your hypothetical GetSyntacticContext method might do something similar: obtain the current stack frame with its file name/line number information and read that line from the file. Something like this:

You need to bump Microsoft.AspNetCore.TestHost to a compatible 3.x version (PR submitted).

There's no magic for this. Your properties are private, hence FluentAssertions will ignore them. In fact, observing the internal details of an object in a test is IMHO bad practice. You should only assert the observable behavior of a class.