MongoDB integration

.devcontainer/devcontainer.json

@@ -3,7 +3,10 @@
 	"image": "mcr.microsoft.com/devcontainers/dotnet:2-10.0-noble",
 	"features": {
 		"ghcr.io/devcontainers/features/node:1": {},
-		"ghcr.io/devcontainers/features/docker-in-docker:2": {}
+		"ghcr.io/devcontainers/features/docker-in-docker:2": {
+			"dockerDashComposeVersion": "none",
+			"installDockerBuildx": false
+		}
 	},
 	"postCreateCommand": "dotnet restore"
 }

.github/workflows/ci.yml

@@ -169,3 +169,67 @@ jobs:
           name: Container Test Results (${{ matrix.database }})
           path: ./test-results/**/*.trx
           reporter: dotnet-trx
+
+  mongodb-tests:
+    name: Container Tests (MongoDB)
+    runs-on: ubuntu-latest
+    needs: build-and-test
+    timeout-minutes: 10
+
+    env:
+      CI: true
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup .NET SDKs
+        uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: |
+            8.0.x
+            9.0.x
+            10.0.x
+
+      - name: Cache NuGet packages
+        uses: actions/cache@v4
+        with:
+          path: ~/.nuget/packages
+          key: nuget-${{ runner.os }}-MongoDB-${{ hashFiles('**/*.csproj', 'Directory.Packages.props') }}
+          restore-keys: |
+            nuget-${{ runner.os }}-MongoDB-
+            nuget-${{ runner.os }}-
+
+      - name: Restore
+        run: >-
+          dotnet restore
+          tests/ExpressiveSharp.MongoDB.IntegrationTests/ExpressiveSharp.MongoDB.IntegrationTests.csproj
+
+      - name: Build
+        run: >-
+          dotnet build --no-restore -c Release
+          tests/ExpressiveSharp.MongoDB.IntegrationTests/ExpressiveSharp.MongoDB.IntegrationTests.csproj
+
+      - name: Test
+        run: >-
+          dotnet test --no-build -c Release
+          --project tests/ExpressiveSharp.MongoDB.IntegrationTests
+          --
+          --report-trx --report-trx-filename results.trx
+          --results-directory ./test-results
+
+      - name: Upload test results
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: container-test-results-MongoDB
+          path: ./test-results/**/*.trx
+          retention-days: 14
+
+      - name: Test report
+        if: always()
+        uses: dorny/test-reporter@v1
+        with:
+          name: Container Test Results (MongoDB)
+          path: ./test-results/**/*.trx
+          reporter: dotnet-trx

Directory.Packages.props

@@ -24,5 +24,7 @@
     <PackageVersion Include="Testcontainers.CosmosDb" Version="4.3.0" />
     <PackageVersion Include="Testcontainers.MySql" Version="4.3.0" />
     <PackageVersion Include="Microsoft.EntityFrameworkCore.Cosmos" Version="8.0.25" />
+    <PackageVersion Include="MongoDB.Driver" Version="3.0.0" />
+    <PackageVersion Include="Testcontainers.MongoDb" Version="4.3.0" />
   </ItemGroup>
 </Project>

ExpressiveSharp.slnx

@@ -15,11 +15,13 @@
     <Project Path="src/ExpressiveSharp.Generator/ExpressiveSharp.Generator.csproj" />
     <Project Path="src/ExpressiveSharp.Abstractions/ExpressiveSharp.Abstractions.csproj" />
     <Project Path="src/ExpressiveSharp/ExpressiveSharp.csproj" />
+    <Project Path="src/ExpressiveSharp.MongoDB/ExpressiveSharp.MongoDB.csproj" />
   </Folder>
   <Folder Name="/tests/">
     <Project Path="tests/ExpressiveSharp.Generator.Tests/ExpressiveSharp.Generator.Tests.csproj" />
     <Project Path="tests/ExpressiveSharp.IntegrationTests/ExpressiveSharp.IntegrationTests.csproj" />
     <Project Path="tests/ExpressiveSharp.EntityFrameworkCore.IntegrationTests/ExpressiveSharp.EntityFrameworkCore.IntegrationTests.csproj" />
     <Project Path="tests/ExpressiveSharp.Tests/ExpressiveSharp.Tests.csproj" />
+    <Project Path="tests/ExpressiveSharp.MongoDB.IntegrationTests/ExpressiveSharp.MongoDB.IntegrationTests.csproj" />
   </Folder>
 </Solution>

src/ExpressiveSharp.MongoDB/ExpressiveMongoCollection.cs

@@ -0,0 +1,56 @@
+using ExpressiveSharp.MongoDB.Extensions;
+using ExpressiveSharp.Services;
+using MongoDB.Driver;
+
+namespace ExpressiveSharp.MongoDB;
+
+/// <summary>
+/// A wrapper around <see cref="IMongoCollection{TDocument}"/> that provides an
+/// <see cref="IExpressiveMongoQueryable{T}"/> for delegate-based LINQ queries
+/// with automatic <c>[Expressive]</c> member expansion.
+/// </summary>
+/// <remarks>
+/// Analogous to <c>ExpressiveDbSet&lt;TEntity&gt;</c> in the EF Core integration.
+/// CRUD operations delegate directly to the inner collection.
+/// </remarks>
+/// <example>
+/// <code>
+/// var orders = new ExpressiveMongoCollection&lt;Order&gt;(collection);
+/// var results = await orders.AsQueryable()
+///     .Where(o => o.Customer?.Name == "Alice")
+///     .ToListAsync();
+/// </code>
+/// </example>
+public class ExpressiveMongoCollection<TDocument>
+{
+    private readonly IMongoCollection<TDocument> _inner;
+    private readonly ExpressiveOptions _options;
+
+    /// <summary>
+    /// Creates a new <see cref="ExpressiveMongoCollection{TDocument}"/> wrapping the specified collection.
+    /// </summary>
+    /// <param name="inner">The underlying MongoDB collection.</param>
+    /// <param name="options">
+    /// Optional <see cref="ExpressiveOptions"/> controlling the transformer pipeline.
+    /// When <c>null</c>, <see cref="MongoExpressiveOptions.CreateDefault"/> is used.
+    /// </param>
+    public ExpressiveMongoCollection(IMongoCollection<TDocument> inner, ExpressiveOptions? options = null)
+    {
+        _inner = inner ?? throw new ArgumentNullException(nameof(inner));
+        _options = options ?? MongoExpressiveOptions.CreateDefault();
+    }
+
+    /// <summary>
+    /// Gets the underlying <see cref="IMongoCollection{TDocument}"/> for direct access
+    /// to non-LINQ operations (inserts, updates, deletes, aggregation pipeline, etc.).
+    /// </summary>
+    public IMongoCollection<TDocument> Inner => _inner;
+
+    /// <summary>
+    /// Returns an <see cref="IExpressiveMongoQueryable{T}"/> that supports delegate-based
+    /// LINQ with modern C# syntax and automatic <c>[Expressive]</c> expansion.
+    /// </summary>
+    /// <param name="aggregateOptions">Optional MongoDB aggregation options.</param>
+    public IExpressiveMongoQueryable<TDocument> AsQueryable(AggregateOptions? aggregateOptions = null)
+        => _inner.AsExpressive(_options, aggregateOptions);
+}

src/ExpressiveSharp.MongoDB/ExpressiveSharp.MongoDB.csproj

@@ -0,0 +1,19 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <Description>MongoDB Driver integration for ExpressiveSharp — automatically expands [Expressive] members in MongoDB LINQ queries</Description>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <InternalsVisibleTo Include="ExpressiveSharp.MongoDB.IntegrationTests" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="MongoDB.Driver" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\ExpressiveSharp\ExpressiveSharp.csproj" />
+  </ItemGroup>
+
+</Project>