Integration tests

Integration tests in fullstackhero spin up real infrastructure in containers - PostgreSQL 17 and MinIO - and exercise the API end-to-end through Microsoft.AspNetCore.Mvc.Testing’s WebApplicationFactory<T>. One factory (and therefore one container set) serves the entire Integration.Tests project via an xUnit collection fixture, so the startup cost is paid once and the per-test cost is small.

The stack

There is no Redis/Valkey container in the shared harness - CachingOptions:Redis is set to an empty string, so HybridCache runs on its in-memory fallback and Hangfire runs on Hangfire.InMemory. The one place a real cache engine matters, Tests/Caching/HybridCacheRedisTests.cs, spins up its own valkey/valkey:9.1.0-alpine container to guard against in-memory-vs-distributed serialization divergence.

The fixture pattern

FshWebApplicationFactory (in src/Tests/Integration.Tests/Infrastructure/) extends WebApplicationFactory<Program> and owns the Postgres + MinIO containers as fields. It is shared across the whole suite through a collection fixture:

[CollectionDefinition(Name)]
public sealed class FshCollectionDefinition : ICollectionFixture<FshWebApplicationFactory>
{
    public const string Name = "FshIntegration";
}

Every test class joins the collection and takes the factory in its constructor:

[Collection(FshCollectionDefinition.Name)]
public sealed class BrandsEndpointTests
{
    private readonly FshWebApplicationFactory _factory;
    private readonly AuthHelper _auth;

    public BrandsEndpointTests(FshWebApplicationFactory factory)
    {
        _factory = factory;
        _auth = new AuthHelper(factory);
    }

    [Fact]
    public async Task CreateBrand_Should_Return200_And_Persist_When_AuthorizedAdmin()
    {
        using var client = await _auth.CreateRootAdminClientAsync();
        var name = UniqueName("CreateOk");

        var createResponse = await client.PostAsJsonAsync($"{TestConstants.CatalogBasePath}/brands", new
        {
            name,
            description = "Brand created by integration test",
            logoUrl = (string?)null,
        });

        createResponse.StatusCode.ShouldBe(HttpStatusCode.OK);

        var brandId = await createResponse.DeserializeAsync<Guid>();
        var getResponse = await client.GetAsync($"{TestConstants.CatalogBasePath}/brands/{brandId}");
        var fetched = await getResponse.DeserializeAsync<BrandDto>();
        fetched.Name.ShouldBe(name);
    }
}

On startup (IAsyncLifetime.InitializeAsync) the factory starts both containers in parallel, creates the MinIO bucket, then migrates the tenant catalog, seeds the root tenant, and runs every module’s IDbInitializer migrate + seed - including the production RolePermissionSyncer. A semaphore stops test classes from racing the migration.

Authenticated test clients

There are no hand-minted JWTs. AuthHelper logs in through the real token endpoint (POST /api/v1/identity/token/issue) as the seeded root admin (admin@root.com), so tokens go through the production auth pipeline:

Constants like TestConstants.RootAdminEmail, TestConstants.DefaultPassword, and the per-module base paths (TestConstants.CatalogBasePath etc.) live in Infrastructure/TestConstants.cs. Tests that need a non-root tenant or a low-privilege user create them through the API - there are no pre-seeded demo tenants in the test database.

What the factory swaps out

The factory overrides configuration and services so tests are deterministic:

• Hangfire runs on Hangfire.InMemory with a real server (1-second polling), so background jobs actually execute.
• Mail is a NoOpMailService - no SMTP, no retries.
• Exceptions surface through a DetailedTestExceptionHandler instead of the generic production error response, so failures tell you what broke.
• Rate limiting and security headers are disabled (they get their own dedicated suite - see below).
• Storage is rewired to S3-against-MinIO after registration:

Two more harness gotchas

• SignalR tests force long polling. TestServer has no WebSocket support, so the chat tests configure HttpTransportType.LongPolling on their hub connections. A hub test that “hangs forever” is almost always a missing transport override.
• Set the tenant context inline. When a test reaches past HTTP into a scoped service (UserManager, a DbContext), it must set the Finbuckle tenant context via IMultiTenantContextSetter in the same method as the call that needs it. The setter writes an AsyncLocal - set it inside an awaited helper and the value is gone when the helper returns, and the tenant query filter NREs.

The middleware suite

Integration.Middleware.Tests is a separate, smaller project that keeps the production middleware wiring: the real GlobalExceptionHandler (RFC 9457 responses), rate limiting with a tiny deterministic window, and security headers enabled. It lives in its own assembly because the module loader is static per process - a second differently-configured host can’t share a process with the main suite.

Test data discipline

• Don’t share state across tests. The whole suite shares one database, and a single collection means hundreds of tests touch the same rows over a run. Use unique names per test (UniqueName("...") / a Guid suffix) so tests stay independent and re-runnable.
• Don’t mutate seeded data. The root tenant and root admin are shared by every test. Create your own tenant/user/brand when you need to mutate one.
• Don’t trust class ordering. xUnit doesn’t guarantee execution order across classes. If a test needs another test to “have created X first,” the test is wrong.

When integration tests get slow

A few-minutes integration suite is acceptable in CI but painful locally. Mitigations:

• Run unit tests first (dotnet test src/Tests/{Module}.Tests/) - they’re fast and they catch most regressions.

• Use --filter to run just the test you’re iterating on:

  dotnet test src/Tests/Integration.Tests/ --filter "FullyQualifiedName~BrandsEndpointTests"

• Don’t add cross-test sleeps. “Wait 200 ms for the cache to settle” is almost always wrong; find the deterministic signal and assert against it.

Running

Docker must be running for Testcontainers to work:

# Run the entire integration suite
dotnet test src/Tests/Integration.Tests/

# Single test class
dotnet test src/Tests/Integration.Tests/ \
  --filter "FullyQualifiedName~BrandsEndpointTests"

# The production-middleware suite
dotnet test src/Tests/Integration.Middleware.Tests/

# Verbose output
dotnet test src/Tests/Integration.Tests/ --logger "console;verbosity=detailed"

CI runs both integration projects on every backend push - see CI/CD.

Related

• Unit tests - for fast in-process tests.
• Architecture tests - for the structural rule families.
• Fixtures & seed data - how the sharing works in detail.