Test.cs

[TestMethod]
public async Task TestSending()
{
    var clientMock = new Mock<DurableOrchestrationClientBase>();
    var logMock = new Mock<ILogger>();
    var orchestrationId = "testId";
    // Mock return value of an orchestration
    clientMock.Setup(context => context.StartNewAsync("O_SendEmail", It.IsAny<object>())).Returns(Task.FromResult(orchestrationId));
    
    var input = new MyClass();
    var requestMessage = new HttpRequestMessage();
    requestMessage.Content = new StringContent(JsonConvert.SerializeObject(input), Encoding.UTF8, "application/json");
    requestMessage = TestHelpers.SetupHttp(requestMessage);

    var result = await MyStarter.Run(requestMessage, this.clientMock.Object, this.logMock.Object);

    Assert.AreEqual(result.StatusCode, HttpStatusCode.OK);
}