Vfrdtyky

I'm going to write some unit tests for my method:

using System.Linq;

...

public int CountEnabledEvents(IEnumerable<Event> events) 

{

    return events.Count(e => e.IsEnabled);

}

As you can see the input of this method is a IEnumerable<Event> collection.

The Event class looks like

public class Event

{

    public Guid Id { get;set; }

    public bool IsEnabled { get;set; }

    public string SomeOtherProp { get;set; }

    ...

}

So I was about to create some dummy events on my test class:

var event1 = new Event() {

    Id = new Guid("..."),

    IsEnabled = true

}

var event2 = new Event() {

    Id = new Guid("xxx"),

    IsEnabled = false

}

The thing is A) this is very tedious, and B) I actually have a ton of real events in my database, and I would like to use the real events on my unit test as testing with real data will make our test more accurate.

¿Is there any kind of software or method to create those dummy Event objects out of real data I have in the database in a automagical way?

Thank you for your time.

EDIT

I thought it was obvius that the code I've provided is a simplification of the actual code. The real method I would like to Unit-test is more complex, as is the actual Event.

So yes, its quite tedious to write down the N^N possibilities for the real event object. And no, I'm not trying to test the integration with the database or anything like that. What I'm trying to do is create static instances coded in the actual test with the data I've got in the database. Not at the testing run-time, but earlier.

I really dont get what's tedious or why using real data would make the test more accurate. You are only looking at the IsEnabled property anyway. A few hard-coded events would do it, but if you want just generated randomized events where the unit test setup tracks how many IsEnabled = true were generated and compare that with the result of calling CountEnabledEvents(randomizedEvents).

The code I shown is just a simplification of the actual one, where
there are lot of possible combinations.

If you want real data as a static unit testing sample there's 2 things that comes to my mind:

1. Create a C# program that reads events from the DB and generates the C# code to instantiate these events, which you then copy in your unit testing setup.




2. You probably already have a mechanism for serializing/de-serializing your events (e.g. from/to JSON). You could read events from the DB in their serialized form, copy that in your unit testing setup, which will also de-serialize the events at runtime.

There are probably a couple of ways to approach this:

You seem to be after state-based unit tests but the test data is extensively represented in a data store. You could use that data store to churn out some state (objects) in c# by generating the relevant "data sets" and then use that.

Another option may be to ring-fence the data in a test data store that serves as the relevant data set and then have some factory/repository/DAO produce the required objects directly from the data store. The data set could be extracted into a much smaller data base that is saved somewhere that is accessible or it may even be extracted into some other format (xml, json) and retrieved from there.

I'm note aware of any mapping software that is going to produce data from a database but I'm thinking that it is probably not too much effort to just write something yourself as this is probably a rather specific bit of data that you are referring to.

I really don't see anything wrong with obtaining the test data from a database for state-based testing; especially if it covers a decent number of possibilities.

You may event go as far as creating an attribute that injects the test values but retrieves them via some implementation of an interface. Along the lines of the TestCase Attribute. It will be slightly more involved than the TestCase attribute and may be a specific attributes that know how to retrieve the data.

update:

I just read the answer provided by p|a|x and we seem to be thinking along the same lines :)

I think you are on the wrong way. Maybe you misunderstood the meaning of a unit test.

• A unit test is just for verifing your code still have the same behaviour after changes.

You will need to search for integration testing for your purposes. If you would like to use it with entity framework 6. Maybe you should have a look to this : https://github.com/zzzprojects/EntityFramework-Effort ( be aware they are also mixing unit and integration tests)