如何针对dotnet核心控制台应用程序运行验收测试？

Question

I am trying to run some acceptance tests against a dotnet core console application. My test continually fails because the console application is not properly started. By properly started I mean the the System.Diagnostics.Process I spawn to run the console app is not doing what I would like.

Here is how I setup the scenario:

Create the console application by running:

dotnet new console -o myconsoleapp

Then modify Program.Main to return a -1 exit code via Environment.Exit(-1)

Create the test project by running:

dotnet new xunit -o myconsoleapp.tests

Add myconsoleapp as a reference in the tests projects:

dotnet add ./myconsoleapp.tests reference ./myconsoleapp

Write the acceptance test:

[Fact]
public void AppExistsWithProperExitCode(){
  var @params = "myconsoleapp.dll";
  using(var sut = Process.Start("dotnet", @params))
  {
    sut.WaitForExit();
    var actual = sut.ExitCode;
    Assert.Equal(-1,actual);
  }
}

After the scenario is setup I run the test:

dotnet test ./myconsoleapp.tests

Running the tests always results in a failure. In an attempt to diagnose the problem I run:

dotnet build ./myconsoleapp.tests
dotnet ./myconsoleapp.tests/bin/Debug/netcoreapp2.2/myconsoleapp.dll

Running those two commands returns the following error message:

A fatal error was encountered. The library 'hostpolicy.dll' required to execute the application was not found in 'myconsoleapp.tests/bin/Debug/netcoreapp2.2/'.
Failed to run as a self-contained app. If this should be a framework-dependent app, add the myconsoleapp.tests/bin/Debug\netcoreapp2.2/myconsoleapp.runtimeconfig.json file specifying the appropriate framework.

The error message is pretty explanatory of what is required, but I am not well versed enough in dotnet core to accomplish my task.

Answer 1

You can create a self contained executable with dotnet publish -c Release -r win10-x64 (for a Windows exe) and then change your test code to

using(var sut = Process.Start(@"<path-to-the-executable>"))
{
  sut.WaitForExit();
  var actual = sut.ExitCode;
  Assert.Equal(-1,actual);
}

This worked on my Windows 10 pc with the preview version of dotnet core 3.

Answer 2

I have determined that there isn't any one answer. Context is key here. I ended up doing something similar to what @Fabio suggested, but @Marius had a reasonable answer as well. Just depends on what exactly you are trying to test.

I wanted to test that the executable ran accordingly. I believe I phrased the original question wrong by saying this was an acceptance test, but it seems more akin to a functional test. The effort to produce a run-able executable within the test was more than I was looking for. I went with testing Program.Main instead.