Coverage of WebApi with integration tests

.editorconfig

@@ -7,6 +7,7 @@ indent_size = 4
 indent_style = space
 insert_final_newline = true
 trim_trailing_whitespace = true
+end_of_line = crlf
 
 [*.{csproj,xml,yml,dll.config,msbuildproj,targets,props,json}]
 indent_size = 2

.gitignore

@@ -8,3 +8,4 @@ Robust.Cdn/content.db*
 Robust.Cdn/manifest.db*
 *.user
 testData/
+/.vs/**

Directory.Packages.props

@@ -14,5 +14,10 @@
     <PackageVersion Include="SharpZstd.Interop" Version="1.5.6" />
     <PackageVersion Include="SharpZstd" Version="1.5.6" />
     <PackageVersion Include="System.CommandLine" Version="2.0.0-beta4.22272.1" />
+    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
+    <PackageVersion Include="xunit" Version="2.9.2" />
+    <PackageVersion Include="xunit.runner.visualstudio" Version="2.8.2" />
+    <PackageVersion Include="coverlet.collector" Version="6.0.2" />
+    <PackageVersion Include="Microsoft.AspNetCore.Mvc.Testing" Version="9.0.0" />
   </ItemGroup>
 </Project>

Robust.Cdn.Tests/ControllerTestCollection.cs

@@ -0,0 +1,12 @@
+using Microsoft.AspNetCore.Mvc.Testing;
+
+namespace Robust.Cdn.Tests;
+
+/// <summary>
+/// Defines a test collection that uses <c>DatabaseFixture</c> for cleanup.
+/// </summary>
+[CollectionDefinition("ControllerTests")]
+public sealed class ControllerTestCollection
+    : ICollectionFixture<WebApplicationFactory<Program>>, ICollectionFixture<DatabaseFixture>
+{
+}

Robust.Cdn.Tests/Controllers/DownloadCompatibilityControllerTests.cs

@@ -0,0 +1,96 @@
+using Microsoft.AspNetCore.Mvc.Testing;
+using System.Net;
+using System.Net.Http.Headers;
+using Xunit.Abstractions;
+
+namespace Robust.Cdn.Tests.Controllers;
+
+/// <summary>
+/// Integration tests for <c>DownloadCompatibilityController</c> (legacy /version/{version}/... routes).
+///
+/// Endpoints:
+///   GET     /version/{version}/manifest
+///   OPTIONS /version/{version}/download
+///   POST    /version/{version}/download
+/// </summary>
+public sealed class DownloadCompatibilityControllerTests(
+    WebApplicationFactory<Program> factory,
+    DatabaseFixture database, 
+    ITestOutputHelper testOutput
+) : DownloadControllerTestBase(factory, database, testOutput)
+{
+    private const string CompatFork = "testfork-compat";
+
+    protected override string ForkName => CompatFork;
+    protected override string RoutePrefix => "/version";
+
+    protected override Dictionary<string, string?> GetConfigurationOverrides()
+    {
+        return new()
+        {
+            ["Cdn:DefaultFork"] = CompatFork,
+            ["Cdn:DatabaseFileName"] = Database.CreateTempDb(),
+            ["Manifest:FileDiskPath"] = Database.CreateTestVersionOnDisk(CompatFork, ExistingVersion, content: FileContent),
+        };
+    }
+
+    [Fact]
+    public async Task GetManifest_VersionNotFound_ReturnsNotFound()
+    {
+        var client = Factory.CreateClient();
+
+        var response = await PollUntilCondition(
+            () => client.GetAsync("/version/0.0.0/manifest"),
+            r => Task.FromResult(r.StatusCode == HttpStatusCode.NotFound));
+
+        Assert.Equal(HttpStatusCode.NotFound, response.StatusCode);
+    }
+
+    [Fact]
+    public async Task GetManifest_DefaultForkNull_ReturnsNotFound()
+    {
+        var client = FactoryWithNoDefaultFork().CreateClient();
+        var response = await client.GetAsync($"/version/{ExistingVersion}/manifest");
+        Assert.Equal(HttpStatusCode.NotFound, response.StatusCode);
+    }
+
+    [Fact]
+    public async Task DownloadOptions_DefaultForkNull_ReturnsNotFound()
+    {
+        var client = FactoryWithNoDefaultFork().CreateClient();
+        var response = await client.SendAsync(new(HttpMethod.Options, $"/version/{ExistingVersion}/download"));
+        Assert.Equal(HttpStatusCode.NotFound, response.StatusCode);
+    }
+
+    [Fact]
+    public async Task DownloadPost_DefaultForkNull_ReturnsNotFound()
+    {
+        var client = FactoryWithNoDefaultFork().CreateClient();
+
+        var content = new ByteArrayContent(new byte[4]);
+        content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
+
+        var request = new HttpRequestMessage(HttpMethod.Post, $"/version/{ExistingVersion}/download")
+        {
+            Content = content
+        };
+        request.Headers.Add("X-Robust-Download-Protocol", "1");
+
+        var response = await client.SendAsync(request);
+        Assert.Equal(HttpStatusCode.NotFound, response.StatusCode);
+    }
+
+    private WebApplicationFactory<Program> FactoryWithNoDefaultFork()
+    {
+        return Factory.WithWebHostBuilder(builder =>
+        {
+            builder.ConfigureAppConfiguration((_, configBuilder) =>
+            {
+                configBuilder.AddInMemoryCollection(new Dictionary<string, string?>
+                {
+                    ["Cdn:DefaultFork"] = null,
+                });
+            });
+        });
+    }
+}