Fix slow NCrunch build

NCrunch is a great unit test runner and has been part of my developer toolbox for many years.

Recently I was having an issue on a medium-sized project where the NCrunch’s Build step was taking almost 2 minutes to complete. That spinning “B” was taking forever!

NCrunch progress

The tests themselves would run in under one minute.

The problem was we use a custom Autofixture [AutoData] attribute on every test.

Our attribute’s constructor creates a TestServer for running the web tests against.
We then inject the test server into each test, i.e.

[Scenario]
[WebHostAutoData]
public void CreateJob_ShouldCreateSuccessfully(
    WebApiClientFixture apiFixture

As it turns out, NCrunch enumerates all test attributes during Analysis, so you should not have any expensive code in your attribute’s constructor.

In my case, I fixed this by introducing a base class for all of my tests, which creates the TestServer (during test run). I then dropped our custom [AutoData] attribute.

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