How to Test a Logic App

TimeForCoffee.feature

Scenario: TimeForCoffee noon test
	Given I send a POST request to 'TimeForCoffee' with the body
	| currentTime |
	| 12:00       |

This is the Given SpecFlow step definition to trigger the POST endpoint of the app. ‘TimeForCoffee’ is an alias to my app’s endpoint and the table is converted to the POST body.

HttpBindings.cs

Given(@"I send a POST request to '(.*)' with the body")]
public void GivenISendAPOSTRequestToWithTheBody(string uriKey, Table table)
{
    var json = JsonConvert.SerializeObject(table.Rows.First());
    var content = new StringContent(json, Encoding.UTF8, "application/json");
    _ = _client.PostAsync(HttpTriggerUris[uriKey], content).Result;
}

We convert the Table rows directly to JSON, then POST it to the app’s endpoint to trigger execution.

LogicAppBindings.cs

[BeforeTestRun]
public static void Initialize()
{
    var credentials = SdkContext.AzureCredentialsFactory
        .FromServicePrincipal(EnvVariables.AzureClientId,
            EnvVariables.AzureClientSecret,
            EnvVariables.AzureTenantId,
            AzureEnvironment.AzureGlobalCloud);
    _retriever = new LogicAppExecutionRetriever(new LogicManagementClient(credentials)
    {
        SubscriptionId = EnvVariables.SubscriptionId
    }, EnvVariables.ResourceGroup);
}

Here, we are creating the credentials required for the LogicManagementClient. The LogicManagementClient is the package we’ll be using to query the Logic App execution history.

LogicAppExecutionRetriever.cs

private WorkflowRun GetLatestWorkflowRun(string logicApp)
{
    return _client
        .WorkflowRuns
        .ListWithHttpMessagesAsync(_resourceGroup, logicApp)
        .Result.Body.First();
}

private IEnumerable<WorkflowRunAction> GetWorkflowRunActions(string logicApp, string workflowRunId)
{
    return _client
        .WorkflowRunActions
        .ListWithHttpMessagesAsync(_resourceGroup, logicApp, workflowRunId)
        .Result.Body.OrderBy(x => x.StartTime);
}

These are the calls we’ll be using to retrieve the WorkflowRun and WorkflowRunActions from our most recent execution. The _client here is the LogicAppManagementClient.

LogicAppExecutionRetriever.cs

public IList<LogicAppEvent> GetLatestExecutionEvents(string logicApp)
{
    var events = new List<LogicAppEvent>();

    var workflowRun = GetLatestWorkflowRun(logicApp);
    events.Add(new LogicAppEvent(workflowRun.Trigger.Name, workflowRun.Trigger.Status));

    var workflowRunActions = GetWorkflowRunActions(logicApp, workflowRun.Name);
    events.AddRange(workflowRunActions.Select(action => new LogicAppEvent(action.Name, action.Status)));

    return events;
}

There are two different major pieces to this:

One, is when we query for the latest workflow run (GetLatestWorkflowRun). The query returns the trigger information so we go ahead and parse that into a LogicAppEvent using workflow.Trigger.Name and workflow.Trigger.Status.

Two, is when we query for the workflow run actions (GetWorkflowRunActions). We iterate over the returned actions and pull the action.Name and action.Status into our list of LogicAppEvents.

TimeForCoffee.feature

Scenario: TimeForCoffee noon test
	When I send a POST request to 'TimeForCoffee' with the body
	| currentTime |
	| 12:00       |
	And I wait '5' seconds for execution to complete
	Then I can verify the following logic app events for 'TimeForCoffee'
	| StepName                       | Status    |
	| manual                         | Succeeded |
	| Initialize_CupsOfCoffeeToDrink | Succeeded |
	| Get_hour_from_currentTime      | Succeeded |
	| Should_get_a_cup_of_coffee     | Succeeded |
	| Determine_number_of_cups       | Succeeded |
	| Number_of_cups_to_drink        | Succeeded |
	| Set_CupsOfCoffeeToDrink        | Succeeded |
	| Until                          | Succeeded |
	| Drink_cup_of_coffee            | Succeeded |
	| Decrement_CupsOfCoffeeToDrink  | Succeeded |
	| Too_late_for_coffee            | Skipped   |

This is the final SpecFlow feature test. As you can see, we have a Then binding that evaluates a table of expected logic app events. These expected steps were extracted from our ‘TimeForCoffee’ Logic App execution.

As you can see, we are able to evaluate each and every step that the Logic App performed. This provides us the insight we need to confirm that certain events executed as expected.

LogicAppBindings.cs

[Then(@"I can verify the following logic app events for '(.*)'")]
public void ThenICanVerifyTheFollowingLogicAppEventsFor(string logicApp, IList<LogicAppEvent> expectedEvents)
{
    var actualEvents = _retriever.GetLatestExecutionEvents(logicApp);
    for (var i = 0; i < expectedEvents.Count; i++)
    {
        var expectedEvent = expectedEvents.ElementAt(i);
        LogicAppEvent actualEvent = null;
        try
        {
            actualEvent = actualEvents.ElementAt(i);
        }
        catch
        {
            Assert.Fail($"Expected to find ({expectedEvent}) and there were no more!");
        }
        Assert.AreEqual(expectedEvent.ToString(), actualEvent.ToString());
    }
}

Here is the code behind the Then step. We get the latest events, then iterate the List of expectedEvents. With each expectedEvent we see if there’s a matching actualEvent.

One thing that does happen behind the scenes is we convert the raw input table into a List of LogicAppEvents using a custom SpecFlow Step Argument Transformation.