Call Local Function action

This is an example of JSON request and response message content for a mocked Call a Local Function action.

Request

The name of the function is located in the functionName field and the input parameters are included in the parameters field.

{
    "functionName": "WeatherForecast",
    "parameters": {
        "zipCode": "13579",
        "temperatureScale": "Fahrenheit"
    }
}

The structure of the JSON in the parameters field will match the request signature of the function that is being called.

Successful Response

The structure of the JSON response must match the response signature of the function that is being called. For example, this JSON response matches a typed response using a class called Weather:

{
    "ZipCode": "13579",
    "CurrentWeather": "The current weather is 41 Fahrenheit",
    "DayLow": "The low for the day is 31 Fahrenheit",
    "DayHigh": "The high for the day is 51 Fahrenheit"
}

where the Weather class is defined as follows:

public class Weather
{
    public int ZipCode { get; set; }
    public string CurrentWeather { get; set; }
    public string DayLow { get; set; }
    public string DayHigh { get; set; }
}

You can easily mock this request and response using the Fluent API:

testRunner
    .AddMockResponse(
        MockRequestMatcher.Create())
    .RespondWith(
        MockResponseBuilder.Create()
        .WithSuccess()
        .WithContentAsJson(new {
            ZipCode = "13579",
            CurrentWeather = "The current weather is 41 Fahrenheit",
            DayLow = "The low for the day is 31 Fahrenheit",
            DayHigh = "The high for the day is 51 Fahrenheit"
        }));

Failed Response

The Call a Local Function action cannot return a HTTP status code indicating a failure because the action does not use the HTTP protocol to invoke the function. Instead, the called function can throw an exception which is caught by the Logic App runtime and presented to the workflow as a failed action.

You can simulate the throwing of an exception in the called function using the Fluent API:

testRunner
    .AddMockResponse(
        MockRequestMatcher.Create())
    .RespondWith(
        MockResponseBuilder.Create()
        .ThrowsException(new InvalidOperationException("Something went bang!")));

In this scenario the HTTP action (that is added by the testing framework and replaces the mocked Call a Local Function action) will return a HTTP 500 (Internal Server Error) status code which is presented to the workflow as a failed action, just like the mocked Call a Local Function action would have done.

If you are using a delegate function to create responses, you can simply throw an exception in the delegate function to acheive the same result.