### YAML Test Structure Example

Source: https://github.com/mongodb/mongo-csharp-driver/blob/main/specifications/server-discovery-and-monitoring/tests/README.rst

Illustrates the basic structure of a YAML test file, including description, URI, and phases.

```yaml
description: "A textual description of the test."
uri: "A connection string."
phases:
  - description: "(optional) A textual description of this phase."
    responses: []
    applicationErrors: []
    outcome: {}

```

--------------------------------

### YAML Phase Response Example

Source: https://github.com/mongodb/mongo-csharp-driver/blob/main/specifications/server-discovery-and-monitoring/tests/README.rst

Shows how to define a response within a test phase, including the source address and the hello response.

```yaml
responses:
  - source: "a:27017"
    response: "{ok: 1, helloOk: true, isWritablePrimary: true}"

```

--------------------------------

### YAML ServerDescription Example

Source: https://github.com/mongodb/mongo-csharp-driver/blob/main/specifications/server-discovery-and-monitoring/tests/README.rst

Defines the expected ServerDescription within a TopologyDescription outcome.

```yaml
servers:
  "a:27017":
    type: "RSSecondary"
    setName: "rs0"
    setVersion: 1
    electionId: null
    minWireVersion: 0
    maxWireVersion: 9
    pool:
      generation: 0

```

--------------------------------

### Watch All Collections in a Database

Source: https://context7.com/mongodb/mongo-csharp-driver/llms.txt

This example shows how to set up a change stream to monitor all collections within a specific database. It uses `db.WatchAsync` with an empty pipeline.

```csharp
// Watch all collections in a database
using var dbCursor = await db.WatchAsync<ChangeStreamDocument<BsonDocument>>(
    new EmptyPipelineDefinition<ChangeStreamDocument<BsonDocument>>());
```

--------------------------------

### Start a new thread

Source: https://github.com/mongodb/mongo-csharp-driver/blob/main/specifications/server-discovery-and-monitoring/tests/README.rst

The 'startThread' operation initiates a new thread with a specified name. This name is used by 'runOnThread' and 'waitForThread'.

```yaml
- name: startThread
  object: testRunner
  arguments:
    name: thread1
```

--------------------------------

### Build Lambda Application with SAM CLI

Source: https://github.com/mongodb/mongo-csharp-driver/blob/main/tests/FaasTests/LambdaTests/README.md

Use 'sam build' to install dependencies, create a deployment package, and prepare your Lambda function for local testing or deployment. Ensure your project's .csproj file lists all necessary dependencies.

```bash
sam build
```

--------------------------------

### Get Database using GetDatabase method

Source: https://github.com/mongodb/mongo-csharp-driver/blob/main/Release Notes/Release Notes v1.8.md

Use the GetDatabase method to retrieve a database instance. This replaces the deprecated indexer access.

```csharp
var database = server.GetDatabase("test");
```

--------------------------------

### Run Driver Benchmarks

Source: https://github.com/mongodb/mongo-csharp-driver/blob/main/benchmarks/MongoDB.Driver.Benchmarks/README.md

Execute the benchmark runner for driver-specific benchmarks. This command starts the benchmark runner and allows selection via console prompts. Ensure a mongod instance is running or specify a custom connection string via the MONGODB_URI environment variable.

```bash
dotnet run -c Release -- --driverBenchmarks
```

--------------------------------

### View Available Benchmark Options

Source: https://github.com/mongodb/mongo-csharp-driver/blob/main/benchmarks/MongoDB.Driver.Benchmarks/README.md

Display a list of all available command-line options for the benchmark runner. This is useful for understanding the full range of customization available for running benchmarks.

```bash
dotnet run -c Release -- --help
```

--------------------------------

### Initialize C# Driver (Recommended)

Source: https://github.com/mongodb/mongo-csharp-driver/blob/main/Release Notes/Release Notes v1.7.md

This is the new recommended way to initialize the C# driver using MongoClient. It defaults to an Acknowledged WriteConcern.

```csharp
var connectionString = "mongodb://localhost";
var client = new MongoClient(connectionString);
var server = client.GetServer();
var database = server.GetDatabase("test"); // WriteConcern defaulted to Acknowledged
```

--------------------------------

### YAML Outcome TopologyDescription Example

Source: https://github.com/mongodb/mongo-csharp-driver/blob/main/specifications/server-discovery-and-monitoring/tests/README.rst

Specifies the expected TopologyDescription outcome for a non-monitoring test.

```yaml
outcome:
  topologyType: "ReplicaSetNoPrimary"
  setName: null
  servers: {}
  logicalSessionTimeoutMinutes: null

```

--------------------------------

### MongoClient - Connecting to MongoDB

Source: https://context7.com/mongodb/mongo-csharp-driver/llms.txt

Demonstrates how to create a MongoClient instance using various connection methods, including connection strings and programmatic settings. It also shows how to list and drop databases.

```APIDOC
## MongoClient — Connecting to MongoDB

`MongoClient` is the entry point for all driver operations. A single `MongoClient` instance is thread-safe and should be shared across the application lifetime. It accepts a connection string or a `MongoClientSettings` object.

```csharp
using MongoDB.Driver;

// Simple connection string
var client = new MongoClient("mongodb://localhost:27017");

// Atlas cluster with credentials
var client = new MongoClient(
    "mongodb+srv://user:password@cluster0.example.mongodb.net/?retryWrites=true&w=majority");

// Programmatic settings with advanced options
var settings = new MongoClientSettings
{
    Servers = new[] { new MongoServerAddress("localhost", 27017) },
    ReplicaSetName = "rs0",
    ReadPreference = ReadPreference.SecondaryPreferred,
    WriteConcern = WriteConcern.WMajority,
    RetryWrites = true,
    RetryReads = true,
    ServerApi = new ServerApi(ServerApiVersion.V1, strict: true),
    ApplicationName = "MyApp"
};
var client = new MongoClient(settings);

// List databases
var cursor = client.ListDatabaseNames();
foreach (var name in cursor.ToEnumerable())
    Console.WriteLine(name); // admin, local, mydb

// Drop a database
await client.DropDatabaseAsync("mydb");
```
```

--------------------------------

### Type Query with OfType<T>()

Source: https://github.com/mongodb/mongo-csharp-driver/blob/main/Release Notes/Release Notes v1.5.md

Example of performing a type query using the OfType<T>() LINQ operator on a collection.

```csharp
collection.AsQueryable().OfType<T>()
```

--------------------------------

### YAML Application Error Example

Source: https://github.com/mongodb/mongo-csharp-driver/blob/main/specifications/server-discovery-and-monitoring/tests/README.rst

Defines an application error to be mocked during testing, specifying the address, type, and when it should occur.

```yaml
applicationErrors:
  - address: "a:27017"
    generation: 1
    maxWireVersion: 9
    when: "beforeHandshakeCompletes"
    type: "command"
    response: "{ok: 0, errmsg: "not primary"}"

```

--------------------------------

### YAML Extended JSON Response Example

Source: https://github.com/mongodb/mongo-csharp-driver/blob/main/specifications/server-discovery-and-monitoring/tests/README.rst

Demonstrates how to represent an ObjectId in an extended JSON format within a hello response.

```yaml
response: "{""$oid"": ""000000000000000000000002""}"

```

--------------------------------

### Create and List Search Indexes

Source: https://github.com/mongodb/mongo-csharp-driver/blob/main/specifications/index-management/tests/README.md

Demonstrates the process of creating a search index and then listing it to verify its creation and properties. This is useful for testing the search index management capabilities of the driver.

```typescript
{
  name: 'test-search-index',
  definition: {
    mappings: { dynamic: false }
  }
}
```

--------------------------------

### Type Query with GetType()

Source: https://github.com/mongodb/mongo-csharp-driver/blob/main/Release Notes/Release Notes v1.5.md

Example of performing a type query using the GetType() method on a property within a typed builder.

```csharp
Query<A>.Where(a => a.GetType() == typeof(T))
```

--------------------------------

### Build CSharpDriver Solution

Source: https://github.com/mongodb/mongo-csharp-driver/blob/main/AGENTS.md

Use this command to build the entire CSharpDriver solution.

```bash
dotnet build CSharpDriver.sln
```

--------------------------------

### Populating the Pool with a Connection

Source: https://github.com/mongodb/mongo-csharp-driver/blob/main/specifications/connection-monitoring-and-pooling/connection-monitoring-and-pooling.rst

This pseudocode details the process of preemptively creating and establishing connections to populate the pool, ensuring it meets the minimum size requirement without blocking application threads. Error handling is deferred to SDAM.

```pseudocode
wait until pendingConnectionCount < maxConnecting and pool is "ready"
create connection
try:
  establish connection
  mark connection as available
except error:
  # Defer error handling to SDAM.
  topology.handle_pre_handshake_error(error)
```

--------------------------------

### Person Class Definition

Source: https://github.com/mongodb/mongo-csharp-driver/blob/main/Release Notes/Release Notes v1.5.md

Example Person class used to demonstrate typed builders. Attributes map C# properties to MongoDB fields.

```csharp
public class Person
{
	[BsonRepresentation(BsonType.ObjectId)]
	public string Id { get; set;}

	[BsonElement("fn")]
	public string FirstName { get; set;}

	[BsonElement("ln")]
	public string LastName { get; set;}

	[BsonElement("age")]
	public int Age { get; set;}
}
```

--------------------------------

### Establishing a Connection

Source: https://github.com/mongodb/mongo-csharp-driver/blob/main/specifications/connection-monitoring-and-pooling/connection-monitoring-and-pooling.rst

This pseudocode outlines the steps involved in establishing a new connection, including the initial handshake, handling compressed messages, and authentication. Errors during this process result in the connection being closed and the error being propagated.

```pseudocode
try:
  connect connection via TCP / TLS
  perform connection handshake
  handle OP_COMPRESSED
  perform connection authentication
  emit ConnectionReadyEvent and equivalent log message
  return connection
except error:
  close connection
  throw error # Propagate error in manner idiomatic to language.
```

--------------------------------

### Marking a Connection as Available

Source: https://github.com/mongodb/mongo-csharp-driver/blob/main/specifications/connection-monitoring-and-pooling/connection-monitoring-and-pooling.rst

This pseudocode illustrates how a connection is marked as 'available' after it has been successfully established. It involves incrementing the available connection count and updating the connection's state.

```pseudocode
increment availableConnectionCount
set connection state to "available"
add connection to availableConnections
```

--------------------------------

### Run Benchmarks by Category

Source: https://github.com/mongodb/mongo-csharp-driver/blob/main/benchmarks/MongoDB.Driver.Benchmarks/README.md

Execute benchmarks belonging to a specific category, such as 'WriteBench'. The `--anyCategories` option selects benchmarks that match any of the provided categories.

```bash
dotnet run -c Release -- --driverBenchmarks --anyCategories "WriteBench"
```

--------------------------------

### Update a Search Index Definition

Source: https://github.com/mongodb/mongo-csharp-driver/blob/main/specifications/index-management/tests/README.md

Specifies the new definition for updating an existing search index. This example shows changing the dynamic mapping setting.

```typescript
{
  name: 'test-search-index',
  definition: {
    mappings: { dynamic: true }
  }
}
```

--------------------------------

### Initialize C# Driver (Deprecated)

Source: https://github.com/mongodb/mongo-csharp-driver/blob/main/Release Notes/Release Notes v1.7.md

This is the older way to initialize the C# driver. It defaults to an Unacknowledged WriteConcern. Use MongoClient for new applications.

```csharp
var connectionString = "mongodb://localhost";
var server = MongoServer.Create(connectionString); // deprecated
var database = server.GetDatabase("test"); // WriteConcern defaulted to Unacknowledged
```

--------------------------------

### Get Collection using GetCollection method

Source: https://github.com/mongodb/mongo-csharp-driver/blob/main/Release Notes/Release Notes v1.8.md

Use the GetCollection method with a type parameter to retrieve a collection instance. This replaces the deprecated indexer access.

```csharp
var collection = database.GetCollection<TDocument>("test");
```

--------------------------------

### Advanced MongoClientSettings Configuration

Source: https://context7.com/mongodb/mongo-csharp-driver/llms.txt

Configure connection pooling, timeouts, compression, TLS, and Server API versions using MongoClientSettings. FromConnectionString is a common starting point.

```csharp
var settings = MongoClientSettings.FromConnectionString(
    "mongodb+srv://user:pass@cluster0.example.mongodb.net/mydb");

// Override specific properties
settings.MaxConnectionPoolSize = 200;
settings.MinConnectionPoolSize = 10;
settings.ConnectTimeout = TimeSpan.FromSeconds(10);
settings.ServerSelectionTimeout = TimeSpan.FromSeconds(30);
settings.SocketTimeout = TimeSpan.FromSeconds(60);
settings.HeartbeatInterval = TimeSpan.FromSeconds(10);

// Stable API — lock to a specific API version
settings.ServerApi = new ServerApi(ServerApiVersion.V1, strict: false, deprecationErrors: false);

// Compression
settings.Compressors = new[]
{
    new CompressorConfiguration(CompressorType.Snappy),
    new CompressorConfiguration(CompressorType.Zlib),
    new CompressorConfiguration(CompressorType.ZStandard)
};

// TLS
settings.SslSettings = new SslSettings { EnabledSslProtocols = System.Security.Authentication.SslProtocols.Tls13 };

// Logging (Microsoft.Extensions.Logging)
settings.LoggingSettings = new LoggingSettings(loggerFactory);

var client = new MongoClient(settings);
```

--------------------------------

### Resume a Change Stream

Source: https://context7.com/mongodb/mongo-csharp-driver/llms.txt

Illustrates how to resume a change stream from a specific point using a resume token. This is crucial for ensuring no changes are missed if the application restarts.

```csharp
// Resume a stream after a restart using a resume token
BsonDocument resumeToken = null;
using var cursor = await products.WatchAsync(
    new EmptyPipelineDefinition<ChangeStreamDocument<Product>>(),
    new ChangeStreamOptions { ResumeAfter = resumeToken });
```

--------------------------------

### Get Database and Collection

Source: https://context7.com/mongodb/mongo-csharp-driver/llms.txt

Access a specific database using GetDatabase and then retrieve a typed or untyped collection using GetCollection. Custom collection settings can be applied.

```csharp
using MongoDB.Bson;
using MongoDB.Driver;

// POCO model
public class Product
{
    public ObjectId Id { get; set; }
    public string Name { get; set; }
    public decimal Price { get; set; }
    public string Category { get; set; }
    public int Stock { get; set; }
}

var client = new MongoClient("mongodb://localhost:27017");
var db = client.GetDatabase("shop");

// Typed collection
var products = db.GetCollection<Product>("products");

// Untyped collection (BsonDocument)
var rawCollection = db.GetCollection<BsonDocument>("events");

// Collection with custom settings
var settings = new MongoCollectionSettings
{
    ReadPreference = ReadPreference.Secondary,
    WriteConcern = WriteConcern.Acknowledged
};
var auditLogs = db.GetCollection<BsonDocument>("audit_logs", settings);

// List collections in the database
var collectionNames = db.ListCollectionNames().ToList();
// Expected: ["products", "events", "audit_logs"]
```

--------------------------------

### Create Multiple Search Indexes in Batch

Source: https://github.com/mongodb/mongo-csharp-driver/blob/main/specifications/index-management/tests/README.md

Demonstrates how to create multiple search indexes on a collection in a single batch operation. Ensure the collection exists before creating indexes.

```typescript
{
  name: 'test-search-index-1',
  definition: {
    mappings: { dynamic: false }
  }
}
```

```typescript
{
  name: 'test-search-index-2',
  definition: {
    mappings: { dynamic: false }
  }
}
```