MongoZen 0.10.6

MongoZen

MongoDB is nice and all, but the driver experience in C# usually sucks. You either end up with reflection-heavy "automagical" repositories, or you're writing manual BsonDocument boilerplate for aggregation pipelines like it's 2011.

Now, the idea behind MongoZen is to take a Mongo driver then add "Unit of Work" and "Identity Map" patterns from EF Core or RavenDB. But I wanted them to actually be fast and as MongoDB-native as possible.

So, why should you care?

• No Reflection on the Hot Path: Instead, there are Roslyn Source Generators to wire up your DbSet and sessions at compile-time. If it's slow, it's not because of us.
• Identity Map: If you load the same document twice in one session, you get the same instance.
• Automatic Change Tracking: Modify POCOs directly. When you call SaveChangesAsync(), we figure out what changed and flush it in a single bulk write operation per collection. Or a transaction if supported.
• RavenDB-inspired API: Store, Delete, LoadAsync. It's a clean API that doesn't get in your way.
• In-Memory Provider: Write tests that run fast without spinning up a Docker "testcontainer" container every time.

Quick Start

1. Define your Context

You need a partial class so the generator can do its thing.

public partial class MyDbContext : MongoZen.DbContext
{
    // These properties are automatically initialized
    public IDbSet<Person> People { get; set; } = null!;

    public MyDbContext(DbContextOptions options) : base(options) { }
}

2. Use it

Everything happens inside a session.

var options = DbContextOptions.CreateForMongo("mongodb://localhost:27017", "MyDatabase");
var db = new MyDbContext(options);

await using var session = db.StartSession();

// Fetch Alice
var alice = await session.LoadAsync<Person>("alice-id");

// Just change the property. No .Update() needed.
alice.Age = 31;

// Load someone else while we're at it
var bob = new Person { Name = "Bob", Age = 25 };
session.Store(bob);

// One network round-trip to commit everything
await session.SaveChangesAsync();

Testing

Just swap the options. It's that simple.

var options = new DbContextOptions(); // Default is In-Memory
var testDb = new MyDbContext(options);

More Info

Check out our Wiki for:

• Detailed How-Tos
• Testing Strategies
• Under the Hood: LINQ Translation

License

MIT. Go build something cool.