How to unit test Azure Functions in Visual Studio - visual-studio

Question

I am using Visual Studio to create Azure Functions. I can create, publish and run functions manually. If I set my Function project to Start Up and run, I host starts. How do I get the Host to start when using MSTest ?
I want to write a test using RestSharp and invoke the functions during the tests - the way the actual applicaion will work. It seems I need a way to get MSTest to start the Azure Function Host.

Answer 1

I was hoping to find an approach similar to debugging Asp.Net/SOAP in older versions of VS where the MSTest engine would start the IISExpress and attach VS to the Asp.Net projects. Edit and continue was supported.
I have worked out the following approaches, so far:
RestSharp Code:
var url = $"http://localhost:7071/api";
var functionKey = "this value is ignored by 'Azure Functions Core Tools' ";
var client = new RestSharp.RestClient(url);
var request = new RestSharp.RestRequest("GetConnectionString", RestSharp.Method.POST);
request.AddHeader("x-functions-key", functionKey);
var response = client.Execute<string>(request);
Option 1:
Run 2nd instance of VS and run the Functions.
Update code to reflect url paths displayed by Azure Functions Core Tools.
Edit and continue works.
Option 2:
Add this class to UnitTest project:
Attach to func.exe process to debug functions
Edit and continue do not work.
[TestClass]
public class Initializer
{
static System.Diagnostics.Process process { get; set; }
[AssemblyInitialize]
public static void Initialize(TestContext context)
{
//process does not use the WorkingDirectory properly with %userprofile%
var userprofile = Environment.GetFolderPath(Environment.SpecialFolder.UserProfile);
var path = $#"{userprofile}\source\repos\mypro\...\myproj.Functions\bin\Debug\netcoreapp3.1";
var startInfo = new ProcessStartInfo
{
FileName = #"cmd.exe",
Arguments = #"/C ""%localappdata%\AzureFunctionsTools\Releases\3.2.0\cli_x64\func.exe host start --port 7071 --pause-on-error""",
//RedirectStandardInput = true,
//RedirectStandardOutput = true,
//RedirectStandardError = true,
//UseShellExecute = false,
UseShellExecute = true,
WorkingDirectory = path
};
process = new System.Diagnostics.Process()
{
StartInfo = startInfo
};
process.Start();
// Thread.Sleep(3000);
}
[AssemblyCleanup]
public static void Cleanup()
{
process.CloseMainWindow();
}
}
Option 3:
Start func.exe process
Working Folder: ...\source\repos\xxx\xxx\xxx.Functions\bin\Debug\netcoreapp3.1\
Command Line:
"C:\Users\username\AppData\Local\AzureFunctionsTools\Releases\3.2.0\cli_x64\func.exe" host start --port 7071 --pause-on-error
Attach to func.exe process.
Edit and continue does not work.