huysentruitw / entity-framework-mock

Easy Mock wrapper for mocking EF6 DbContext and DbSet using Moq or NSubstitute

EntityFrameworkMock

Easy Mock wrapper for mocking EF6 DbContext and DbSet in your unit-tests. Integrates with Moq or NSubstitute.

For mocking Entity Framework Core (EF Core) see https://github.com/huysentruitw/entity-framework-core-mock

Get it on NuGet

Moq integration

PM> Install-Package EntityFrameworkMock.Moq

NSubstitute integration

PM> Install-Package EntityFrameworkMock.NSubstitute

Supports

• In-memory storage of test data
• Querying of in-memory test data (synchronous or asynchronous)
• Tracking of updates, inserts and deletes of in-memory test data
• Emulation of SaveChanges and SaveChangesAsync (only saves tracked changes to the mocked in-memory DbSet when one of these methods are called)
• Auto-increment identity columns, annotated by the [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)] attribute
• Primary key on multiple columns, annotated by the [Key, Column(Order = X)] attributes
• Throwing a DbUpdateException when inserting 2 or more entities with the same primary key while calling SaveChanges / SaveChangesAsync (emulating EF behavior)
• Throwing a DbUpdateConcurrencyException when removing a model that no longer exists (emulating EF behavior)

For the Moq version, you can use all known Moq features, since both DbSetMock and DbContextMock inherit from Mock<DbSet> and Mock<DbContext> respectively.

Example usage

public class User
{
    [Key, Column(Order = 0)]
    public Guid Id { get; set; }

    public string FullName { get; set; }
}

public class TestDbContext : DbContext
{
    public TestDbContext(string connectionString)
        : base(connectionString)
    {
    }

    public virtual DbSet<User> Users { get; set; }
}

[TestFixture]
public class MyTests
{
    var initialEntities = new[]
        {
            new User { Id = Guid.NewGuid(), FullName = "Eric Cartoon" },
            new User { Id = Guid.NewGuid(), FullName = "Billy Jewel" },
        };

    var dbContextMock = new DbContextMock<TestDbContext>("fake connectionstring");
    var usersDbSetMock = dbContextMock.CreateDbSetMock(x => x.Users, initialEntities);

    // Pass dbContextMock.Object to the class/method you want to test

    // Query dbContextMock.Object.Users to see if certain users were added or removed
    // or use Mock Verify functionality to verify if certain methods were called: usersDbSetMock.Verify(x => x.Add(...), Times.Once);
}