Arrange

# Arrange

The Arrange part of a test case can be quite complex to setup. For example:

Run schema changes
Clean the database
Clean caches and sessions
Clean directories
Create basic seed data (e.g. users)
Create the test scenario (e.g. entities, mocks returns, and etc)

Miru makes the Arrange part a bit easy.

Most of all features presented in this article can be configured globally

# Infrastructure

By default, Miru comes configured to arrange infrastructure services, like database, files, etc:

public static void TestingDefault(this TestRunConfig run)
{
    run.BeforeSuite(_ =>
    {
        _.MigrateDatabase();
    });

    run.BeforeCase(_ =>
    {
        _.Logout();
        
        _.ClearFabricator();
        _.ClearDatabase();
        _.ClearQueue();
    });
}

This configuration is applied globally

Miru uses Respawn to clean the database.

# Fabrication

Arranging objects like Entities or Requests can be time-consuming and verbose. Miru comes with a module called Fabrication which makes it easy to create these objects with some real-world fake data using Bogus.

Create these objects can be done through Make and MakeMany:

// arrange
var owner = _.Make<User>();

// Owner:
// Display: Leopoldo30@gmail.com
// Email: Leopoldo30@gmail.com
// Name: Elinor

var project = _.Make<Project>(m => m.User = owner);

// Project:
// Name: Tianna
// Description: Magni nisi animi rem quis quibusdam. Sapiente quod eum. Vitae...
// User:
//   Display: Leopoldo30@gmail.com
//   Email: Leopoldo30@gmail.com
//   Name: Elinor
// Goal: 83
// TotalDonations: 169
// Category:
//   Name: Violet
// IsActive: true
// ...

# Configuring

It's possible to configure conventions for how Fabricator make objects. The configurations are set at /tests/{AppName.Tests}/{AppName}Fabricator.cs:

public class SupportreonFabricator : Fabricator
{
    public SupportreonFabricator(FabSupport context) : base(context)
    {
        Fixture.AddConvention(conv =>
        {
            conv
              .IfPropertyIs<Project>(p => p.MinimumDonation)
              .Use(f => f.Finance.Amount(max: 10));
        }
    }
}

In the code above, f inside method Use is a Faker object from Bogus. It allows generating random quite realistic data.

var project = _.Make<Project>();

// Projects:
// - Name: Earlene
//   MinimumDonation: 9.83
// - Name: Rigoberto
//   MinimumDonation: 8.82
// - Name: Uriah
//   MinimumDonation: 8.76

# Making

To make objects Make and MakeMany methods can be used:

var project = _.Make<Project>();

// Can set properties:
var admin = _.Make<User>(m => m.IsAdmin = true);

// Create 2 users:
var users = _.MakeMany<User>(2, m => m.IsAdmin = false);

# Your Extensions

Arranging the same thing a lot of times can get repetitive and verbose. When this happens, you can create Extensions Methods for TestFixture.

For example, some tests need to fabricate an User, save, and login:

// arrange
var user = _.Make<User>();
await _.SaveAsync(user);
_.LoginAs(user);

Can be replaced with:

// arrange
var user = _.MakeSavingLogin<User>();

The Extension Method looks like this:

public static TUser MakeSavingLogin<TUser>(this ITestFixture fixture, TUser user) 
  where TUser : class, IUser
{
    MiruTest.Log.Debug(() => $"Saving: {user}");
    
    fixture.Save(user);
    
    fixture.LoginAs(user);

    return user;
}