How to unit test Durable Functions with CallActivityWithRetryAsync - unit-testing

Question

I've read Microsoft documentation on Unit Testing
Unit testing: https://learn.microsoft.com/en-us/azure/azure-functions/durable/durable-functions-unit-testing
So for example, based on the MS documentation, if this is my orchestrator:
[FunctionName("SagaToTestOrchestrator")]
public static async Task<ShippingPrice> RunOrchestrator(
[OrchestrationTrigger] IDurableOrchestrationContext context)
{
var input = context.GetInput<SagaContext>();
RetryOptions _retryOptions = RetryConfiguration.GetActivityRetryOptions();
// activity to get proper orchestrator for continent for shipping partner
var supplierOrchestratorToRun = await context.CallActivityWithRetryAsync<string>("GetSupplierOrchestratorForContinent", _retryOptions, input.Continent);
// orchestrator to get the price for the shipping address
var priceForShipment =
await context.CallSubOrchestratorAsync<decimal>($"{supplierOrchestratorToRun}Orchestrator", input);
// activity to publish event for Sales / marketing
await context.CallActivityWithRetryAsync("PublishCalculatedPriceActivity", _retryOptions,(input, priceForShipment));
return new ShippingPrice()
{
Shippable = true,
Price = priceForShipment
};
}
[FunctionName("CourierAOrchestrator")]
public static async Task<decimal> CourierAOrchestrator([OrchestrationTrigger] IDurableOrchestrationContext context)
{
return 100;
}
[FunctionName("CourierBOrchestrator")]
public static async Task<decimal> CourierBOrchestrator([OrchestrationTrigger] IDurableOrchestrationContext context)
{
return 120;
}
[FunctionName("IsContinentSupported")]
public static async Task<bool> IsContinentSupported([ActivityTrigger] string continent, ILogger log)
{
var supportedContinents = new List<string>
{
"North America", "South America", "Europe",
};
return supportedContinents.Contains(continent);
}
[FunctionName("GetSupplierOrchestratorForContinent")]
public static async Task<string> GetSupplierOrchestratorForContinent([ActivityTrigger] string continent, ILogger log)
{
var courier = "";
switch (continent)
{
case "South America":
case "North America":
courier = "CourierA";
break;
case "Europe":
courier = "CourierB";
break;
}
return courier;
}
[FunctionName("PublishCalculatedPriceActivity")]
public static async Task PublishCalculatedPriceActivity([ActivityTrigger] (SagaContext context, decimal price) input, ILogger log)
{
log.LogInformation($"{input.context.Continent}: {input.price}");
}
public class ShippingPrice
{
public bool Shippable { get; set; }
public decimal Price { get; set; }
public string Message { get; set; }
}
public class SagaContext
{
public string Street { get; set; }
public string City { get; set; }
public string Country { get; set; }
public string Continent { get; set; }
}
And my test would be something like this:
public async Task CalculatePriceForAmerica()
{
// Arrange / Given
var orchContext = new SagaContext
{
Continent = "North America"
};
var context = new Mock<IDurableOrchestrationContext>();
// mock the get input
context.Setup(m =>
m.GetInput<SagaContext>()).Returns(orchContext);
// set-up mocks for activity
context.Setup(m
=> m.CallActivityWithRetryAsync<string>("GetSupplierOrchestratorForContinent", _retryOptions, It.IsAny<object>()))
.ReturnsAsync("CourierA");
// set-up mocks for suborchstrators
context.Setup(m =>
m.CallSubOrchestratorAsync<decimal>("CourierAOrchestrator", It.IsAny<string>(), It.IsAny<object>()))
.ReturnsAsync(100);
// ACT / When
var price = await SagaToTestOrchestrator.RunOrchestrator(context.Object);
// Assert / Then
Assert.True(price.Shippable);
Assert.Equal(100, price.Price);
}
Here the issue I am facing is
setup mock data for the GetSupplierOrchestratorForContinent Activity , so ideally it should return "CourierA" as output when the actual Orchestrator method is called but it is returning null.