Steckbrett.SpecsSupport is a library of helper “steps” to easily generate model instances in SpecFlow specifications. It integrates AutoPoco and AutoMapper libraries.
Apart from configuring the model, there is only one extra requirement to use these helpers in specifications: In order to activate the model mapping configurations, you have to tag the feature with @model_mapping
Let's see the whole thing in action using a project that provides sample usage features. In App.config, SpecFlow is instructed to include steps defined in Steckbrett.SpecsSupport.dll assembly (<stepAssemblies> section). A simple sample model is configured in ModelMappingEvents.cs . Below you can see some sample scenarios: the steps shown in red are helpers defined in Steckbrett.SpecsSupport.dll ; underscored fragments are step arguments.
A sample scenario of (pseudo-)random instance generation (see more in AutoPoco.feature):
Scenario: Generating a consecutive number of random instances
Given 3 random instances of Customer
Given 2 random instances of Customer
Then I should have 5 random instances of Customer
Some sample scenarios of table mappings (see more in AutoMapper.feature):
Scenario: Mapping table to Customer
Given the following instance of Customer:
| FirstName | LastName |
| John | Doe |
Then I should have a Customer called John Doe
Scenario: Mapping tables to Order and Details, add to parent list with implicit typing
Given the following instance of Order:
| Id |
| 1 |
And the following instances added to Details of Order 1:
| Price | Quantity |
| 150 | 2 |
| 200 | 1 |
When I calculate Order 1 total
Then I should get total 500 in Order 1
Scenario: Mapping self-referencing table to Customer
Given the following instance of Customer:
| Id | FirstName | LastName | Parent |
| 1 | John | Doe | null |
| 2 | John | Doe | 1 |
Then I should have Customer 1 referencing to no parent customer
And I should have Customer 2 referencing to parent customer 1
Scenario: Mapping from file
Given instances of Customer from file Data\Customers.gherkin
Then I should have 15 instances of Customer
You can access the model instances from your steps using extension methods on ScenarioContext. For example:
[Then(@"I should get total (.+) in Order (\d+)")]
public void ThenIShouldGetTotalInOrder(decimal total, int orderId)
{
var order = ScenarioContext.Current.InstanceById<Order>(orderId);
Assert.That(order.Total, Is.EqualTo(total));
}
[Then(@"the first instance of Customer should have Id (\d+)")]
public void ThenTheFirstInstanceOfCustomerShouldHaveId(int id)
{
var customer = ScenarioContext.Current.InstancesOf<Customer>().FirstOrDefault();
Assert.That(customer, Is.Not.Null);
Assert.That(customer.Id, Is.EqualTo(id));
}
That's all folks! All the trickiness of model instantiation is hidden behind the helper steps so you can focus on writing gorgeous specs.
Your feedback is welcome.
_______________________________________________________
UPDATE 2010-05-27: Inspired by Pickle (thanks to Jonas Bandi for the tip), I’ve just added some assertions steps. See Assertions.feature for examples.
_______________________________________________________
PS: "Steckbrett" is the name of the in-house framework we use in our company. It's German for "plugboard". :-)
