Fix seed pipeline crash and make seeding failures fail CI (#309)

.github/workflows/tests.yml

@@ -33,7 +33,7 @@ jobs:
         if: always()
         run: |
           status=0
-          for name in test-env-api-specs test-env-unit-tests test-env-frontend-tests; do
+          for name in test-env-database-migrations test-env-database-seed test-env-api-specs test-env-unit-tests test-env-frontend-tests; do
             code="$(docker inspect -f '{{.State.ExitCode}}' "$name" 2>/dev/null || echo 1)"
             echo "$name exited with $code"
             if [ "$code" != "0" ]; then

docs/web/diagrams/vertical-slice.md

@@ -98,7 +98,7 @@ see the notes for what else each of those foundation projects pulls in.
 - **Omitted from the diagram**:
   - `Domain.Exceptions` (referenced by nearly every project directly, including
     all of `Shared.Contracts` and each feature slice)
-  - `Infrastructure.Configuration` (the shared options-binding project
+  - `Configuration` (the shared options-binding project
     referenced by `Database.Connection`, `Features.PhotoUpload`,
     and `Features.Emails` directly)
   - both are plumbing-level dependencies of nearly everything above, and drawing

docs/web/docker.md

@@ -98,7 +98,7 @@ sqlserver           # Test database
 database.migrations # Fresh schema
 database.seed      # Test data
 api.specs          # Reqnroll BDD tests
-unit.tests         # All Features.*.Tests unit test projects
+unit.tests         # All Features.*.Tests and Shared.*.Tests unit test projects
 frontend.tests     # Storybook Vitest + Playwright suites (own Playwright image)
 ```
 

docs/web/testing.md

@@ -76,10 +76,11 @@ docker compose --env-file web/.env.test -f web/docker-compose.test.yaml down -v
 
 You can run individual test projects locally without Docker:
 
-### Feature slice unit tests
+### Feature slice and shared unit tests
 
 Each feature slice has its own test project, covering its command/query
-handlers:
+handlers. Shared cross-cutting code (e.g. MediatR pipeline behaviors) has
+its own test project under `Shared/`:
 
 ```bash
 cd web/backend
@@ -87,9 +88,10 @@ dotnet test Features/Features.Users.Tests/Features.Users.Tests.csproj
 dotnet test Features/Features.Breweries.Tests/Features.Breweries.Tests.csproj
 dotnet test Features/Features.Emails.Tests/Features.Emails.Tests.csproj
 dotnet test Features/Features.PhotoUpload.Tests/Features.PhotoUpload.Tests.csproj
+dotnet test Shared/Shared.Application.Tests/Shared.Application.Tests.csproj
 
 # Or run all of them at once via the solution:
-for proj in Features/*.Tests; do dotnet test "$proj"; done
+for proj in Features/*.Tests Shared/*.Tests; do dotnet test "$proj"; done
 ```
 
 **Requirements**:

web/backend/API/API.Core/API.Core.csproj

@@ -22,7 +22,7 @@
         <ProjectReference Include="..\..\Domain\Domain.Entities\Domain.Entities.csproj" />
         <ProjectReference Include="..\..\Domain\Domain.Exceptions\Domain.Exceptions.csproj" />
         <ProjectReference Include="..\..\Database\Database.Connection\Database.Connection.csproj" />
-        <ProjectReference Include="..\..\Infrastructure\Infrastructure.Configuration\Infrastructure.Configuration.csproj" />
+        <ProjectReference Include="..\..\Configuration\Configuration.csproj" />
         <ProjectReference Include="..\..\Features\Features.Breweries\Features.Breweries.csproj" />
         <ProjectReference Include="..\..\Features\Features.Users\Features.Users.csproj" />
         <ProjectReference Include="..\..\Features\Features.Emails\Features.Emails.csproj" />

web/backend/API/API.Core/Authentication/JwtAuthenticationHandler.cs

@@ -1,7 +1,7 @@
 using System.Security.Claims;
 using System.Text.Encodings.Web;
 using Features.Users.Services;
-using Infrastructure.Configuration;
+using Configuration;
 using Microsoft.AspNetCore.Authentication;
 using Microsoft.Extensions.Options;
 using Microsoft.Extensions.Primitives;

web/backend/API/API.Core/Dockerfile

@@ -33,8 +33,9 @@ COPY ["Features/Features.PhotoUpload/Features.PhotoUpload.csproj", "Features/Fea
 COPY ["Features/Features.PhotoUpload.Tests/Features.PhotoUpload.Tests.csproj", "Features/Features.PhotoUpload.Tests/"]
 COPY ["Features/Features.Users/Features.Users.csproj", "Features/Features.Users/"]
 COPY ["Features/Features.Users.Tests/Features.Users.Tests.csproj", "Features/Features.Users.Tests/"]
-COPY ["Infrastructure/Infrastructure.Configuration/Infrastructure.Configuration.csproj", "Infrastructure/Infrastructure.Configuration/"]
+COPY ["Configuration/Configuration.csproj", "Configuration/"]
 COPY ["Shared/Shared.Application/Shared.Application.csproj", "Shared/Shared.Application/"]
+COPY ["Shared/Shared.Application.Tests/Shared.Application.Tests.csproj", "Shared/Shared.Application.Tests/"]
 COPY ["Shared/Shared.Contracts/Shared.Contracts.csproj", "Shared/Shared.Contracts/"]
 RUN dotnet restore "Biergarten.API.slnx"
 COPY . .

web/backend/API/API.Core/ServiceCollectionExtensions.cs

@@ -46,6 +46,7 @@ internal static class ServiceCollectionExtensions
                     cfg.RegisterServicesFromAssembly(typeof(UploadPhotoCommand).Assembly);
                     cfg.RegisterServicesFromAssembly(typeof(IEmailDispatcher).Assembly);
                     cfg.RegisterServicesFromAssembly(typeof(CityController).Assembly);
+                    cfg.AddOpenBehavior(typeof(UnhandledExceptionLoggingBehavior<,>));
                     cfg.AddOpenBehavior(typeof(ValidationBehavior<,>));
                 });
 

web/backend/API/API.Specs/API.Specs.csproj

@@ -38,7 +38,7 @@
 
     <ItemGroup>
         <ProjectReference Include="..\API.Core\API.Core.csproj" />
-        <ProjectReference Include="..\..\Infrastructure\Infrastructure.Configuration\Infrastructure.Configuration.csproj" />
+        <ProjectReference Include="..\..\Configuration\Configuration.csproj" />
         <ProjectReference Include="..\..\Features\Features.Emails\Features.Emails.csproj" />
         <ProjectReference Include="..\..\Features\Features.Locations\Features.Locations.csproj" />
         <ProjectReference Include="..\..\Database\Database.Connection\Database.Connection.csproj" />

web/backend/API/API.Specs/Dockerfile

@@ -23,8 +23,9 @@ COPY ["Features/Features.PhotoUpload/Features.PhotoUpload.csproj", "Features/Fea
 COPY ["Features/Features.PhotoUpload.Tests/Features.PhotoUpload.Tests.csproj", "Features/Features.PhotoUpload.Tests/"]
 COPY ["Features/Features.Users/Features.Users.csproj", "Features/Features.Users/"]
 COPY ["Features/Features.Users.Tests/Features.Users.Tests.csproj", "Features/Features.Users.Tests/"]
-COPY ["Infrastructure/Infrastructure.Configuration/Infrastructure.Configuration.csproj", "Infrastructure/Infrastructure.Configuration/"]
+COPY ["Configuration/Configuration.csproj", "Configuration/"]
 COPY ["Shared/Shared.Application/Shared.Application.csproj", "Shared/Shared.Application/"]
+COPY ["Shared/Shared.Application.Tests/Shared.Application.Tests.csproj", "Shared/Shared.Application.Tests/"]
 COPY ["Shared/Shared.Contracts/Shared.Contracts.csproj", "Shared/Shared.Contracts/"]
 RUN dotnet restore "Biergarten.API.slnx"
 COPY . .

web/backend/API/API.Specs/Steps/AuthSteps.cs

@@ -2,7 +2,7 @@ using System.Text;
 using System.Text.Json;
 using Features.Users.Services;
 using FluentAssertions;
-using Infrastructure.Configuration;
+using Configuration;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Reqnroll;

web/backend/Biergarten.API.slnx

@@ -19,8 +19,8 @@
         <Project Path="Domain/Domain.Entities/Domain.Entities.csproj" />
         <Project Path="Domain/Domain.Exceptions/Domain.Exceptions.csproj" />
     </Folder>
-    <Folder Name="/Infrastructure/">
-        <Project Path="Infrastructure/Infrastructure.Configuration/Infrastructure.Configuration.csproj" />
+    <Folder Name="/Configuration/">
+        <Project Path="Configuration/Configuration.csproj" />
     </Folder>
     <Folder Name="/Features/" />
     <Folder Name="/Features/Users/">
@@ -47,5 +47,6 @@
     <Folder Name="/Shared/">
         <Project Path="Shared/Shared.Contracts/Shared.Contracts.csproj" />
         <Project Path="Shared/Shared.Application/Shared.Application.csproj" />
+        <Project Path="Shared/Shared.Application.Tests/Shared.Application.Tests.csproj" />
     </Folder>
 </Solution>

web/backend/Configuration/Configuration.csproj

@@ -3,7 +3,7 @@
         <TargetFramework>net10.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
         <Nullable>enable</Nullable>
-        <RootNamespace>Infrastructure.Configuration</RootNamespace>
+        <RootNamespace>Configuration</RootNamespace>
     </PropertyGroup>
 
     <ItemGroup>

web/backend/Configuration/ConfigurationHelpers.cs

@@ -1,6 +1,6 @@
 using Microsoft.Extensions.Configuration;
 
-namespace Infrastructure.Configuration;
+namespace Configuration;
 
 public static class ConfigurationHelpers
 {

web/backend/Configuration/ConfigurationKeys.cs

@@ -1,4 +1,4 @@
-namespace Infrastructure.Configuration;
+namespace Configuration;
 
 public static class ConfigurationKeys
 {

web/backend/Database/Database.Connection/Database.Connection.csproj

@@ -21,6 +21,6 @@
         />
     </ItemGroup>
     <ItemGroup>
-        <ProjectReference Include="..\..\Infrastructure\Infrastructure.Configuration\Infrastructure.Configuration.csproj" />
+        <ProjectReference Include="..\..\Configuration\Configuration.csproj" />
     </ItemGroup>
 </Project>

web/backend/Database/Database.Connection/DefaultSqlConnectionFactory.cs

@@ -1,4 +1,4 @@
-using Infrastructure.Configuration;
+using Configuration;
 using Microsoft.Data.SqlClient;
 using Microsoft.Extensions.Configuration;
 

web/backend/Database/Database.Connection/SqlConnectionStringHelper.cs

@@ -1,4 +1,4 @@
-using Infrastructure.Configuration;
+using Configuration;
 using Microsoft.Data.SqlClient;
 using Microsoft.Extensions.Configuration;
 

web/backend/Database/Database.Migrations/Database.Migrations.csproj

@@ -19,7 +19,7 @@
     </ItemGroup>
     <ItemGroup>
         <ProjectReference Include="..\..\Database\Database.Connection\Database.Connection.csproj" />
-        <ProjectReference Include="..\..\Infrastructure\Infrastructure.Configuration\Infrastructure.Configuration.csproj" />
+        <ProjectReference Include="..\..\Configuration\Configuration.csproj" />
     </ItemGroup>
     <ItemGroup>
         <EmbeddedResource Include="scripts/**/*.sql" />

web/backend/Database/Database.Migrations/Program.cs

@@ -1,5 +1,5 @@
 using Database.Connection;
-using Infrastructure.Configuration;
+using Configuration;
 using Microsoft.Data.SqlClient;
 using Microsoft.Extensions.Configuration;
 

web/backend/Database/Database.Seed/Program.cs

@@ -19,7 +19,7 @@ namespace Database.Seed;
 
 internal class Program
 {
-    private static IMediator CreateMediator()
+    private static ServiceProvider BuildServiceProvider()
     {
         IConfiguration configuration = new ConfigurationBuilder().AddEnvironmentVariables().Build();
 
@@ -38,11 +38,10 @@ internal class Program
                     .RegisterServicesFromAssemblyContaining<UploadPhotoCommand>()
             );
 
-        using ServiceProvider provider = services.BuildServiceProvider();
-        return provider.GetRequiredService<IMediator>();
+        return services.BuildServiceProvider();
     }
 
-    public static async Task Main()
+    public static async Task<int> Main()
     {
         using CancellationTokenSource cts = new();
         Console.CancelKeyPress += (_, e) =>
@@ -54,20 +53,24 @@ internal class Program
 
         try
         {
-            IMediator mediator = CreateMediator();
+            await using ServiceProvider provider = BuildServiceProvider();
+            IMediator mediator = provider.GetRequiredService<IMediator>();
             SeedRepository reader = new SeedRepository(
                 connectionString: "Data Source=SeedData/biergarten_seed_2026-08-25T20-45-50.697244Z.sqlite"
             );
             await new BiergartenDataSeeder(mediator, reader).Run(cts.Token);
+            return 0;
         }
         catch (OperationCanceledException)
         {
             AnsiConsole.MarkupLine("[yellow]Seeding cancelled.[/]");
+            return 1;
         }
         catch (Exception ex)
         {
             AnsiConsole.MarkupLine("[red]Seeding failed.[/]");
             AnsiConsole.WriteException(ex);
+            return 1;
         }
     }
 }

web/backend/Database/Database.Seed/Sqlite/PipelineSeedDataReader.cs

@@ -58,13 +58,13 @@ public sealed class SeedRepository : IDisposable
     }
 
     private sealed record BreweryRow(
-        int Id,
+        long Id,
         string NameEn,
         string DescriptionEn,
         string NameLocal,
         string DescriptionLocal,
-        int AddressId,
-        int CityId,
+        long AddressId,
+        long CityId,
         double Longitude,
         double Latitude,
         string AddressLine1,
@@ -101,27 +101,27 @@ public sealed class SeedRepository : IDisposable
 
         return [.. rows.Select(row => new BreweryResult
             {
-                Id = row.Id,
+                Id = (int)row.Id,
                 NameEn = row.NameEn,
                 DescriptionEn = row.DescriptionEn,
                 NameLocal = row.NameLocal,
                 DescriptionLocal = row.DescriptionLocal,
                 Address = new BreweryAddress
                 {
-                    Id = row.AddressId,
-                    CityId = row.CityId,
-                    BreweryId = row.Id,
+                    Id = (int)row.AddressId,
+                    CityId = (int)row.CityId,
+                    BreweryId = (int)row.Id,
                     Longitude = row.Longitude,
                     Latitude = row.Latitude,
                     AddressLine1 = row.AddressLine1,
                     PostalCode = row.PostalCode,
-                    City = cities[row.CityId],
+                    City = cities[(int)row.CityId],
                 },
             })];
     }
 
     private sealed record UserRow(
-        int Id,
+        long Id,
         string FirstName,
         string LastName,
         string Gender,
@@ -130,8 +130,8 @@ public sealed class SeedRepository : IDisposable
         double ActivityWeight,
         string Email,
         string DateOfBirth,
-        int AddressId,
-        int CityId,
+        long AddressId,
+        long CityId,
         double Longitude,
         double Latitude
     );
@@ -172,16 +172,16 @@ public sealed class SeedRepository : IDisposable
                 DateOfBirth = row.DateOfBirth,
                 Address = new UserAddress
                 {
-                    Id = row.AddressId,
-                    CityId = row.CityId,
-                    UserId = row.Id,
+                    Id = (int)row.AddressId,
+                    CityId = (int)row.CityId,
+                    UserId = (int)row.Id,
                     Longitude = row.Longitude,
                     Latitude = row.Latitude,
-                    City = cities[row.CityId],
+                    City = cities[(int)row.CityId],
                 },
                 User = new UserResult
                 {
-                    Id = row.Id,
+                    Id = (int)row.Id,
                     FirstName = row.FirstName,
                     LastName = row.LastName,
                     Gender = row.Gender,
@@ -193,7 +193,7 @@ public sealed class SeedRepository : IDisposable
     }
 
     private sealed record CityRow(
-        int Id,
+        long Id,
         string CityName,
         string StateProvince,
         string Iso31662,
@@ -231,10 +231,10 @@ public sealed class SeedRepository : IDisposable
         IEnumerable<CityRow> rows = await connection.QueryAsync<CityRow>(command);
 
         return rows.ToDictionary(
-            row => row.Id,
+            row => (int)row.Id,
             row => new City
             {
-                Id = row.Id,
+                Id = (int)row.Id,
                 CityName = row.CityName,
                 StateProvinceName = row.StateProvince,
                 ISO_3166_2 = row.Iso31662,

web/backend/Dockerfile.tests

@@ -5,11 +5,11 @@ COPY . .
 RUN dotnet restore "Biergarten.API.slnx"
 RUN dotnet build "Biergarten.API.slnx" -c $BUILD_CONFIGURATION
 
-# Runs every Features.*.Tests project (unit + DbMocker-backed repository tests). API.Specs is
-# excluded here since it's a separate BDD/integration suite, run by its own compose service
-# against the live, seeded database.
+# Runs every Features.*.Tests and Shared.*.Tests project (unit + DbMocker-backed repository
+# tests). API.Specs is excluded here since it's a separate BDD/integration suite, run by its own
+# compose service against the live, seeded database.
 FROM build AS final
 ARG BUILD_CONFIGURATION=Release
 WORKDIR /src
 RUN mkdir -p /app/test-results
-ENTRYPOINT ["sh", "-c", "set -e; for proj in Features/*.Tests; do dotnet test \"$proj\" -c ${BUILD_CONFIGURATION:-Release} --logger \"trx;LogFileName=/app/test-results/$(basename \"$proj\").trx\"; done"]
+ENTRYPOINT ["sh", "-c", "set -e; for proj in Features/*.Tests Shared/*.Tests; do dotnet test \"$proj\" -c ${BUILD_CONFIGURATION:-Release} --logger \"trx;LogFileName=/app/test-results/$(basename \"$proj\").trx\"; done"]

web/backend/Features/Features.Emails/Features.Emails.csproj

@@ -15,7 +15,7 @@
     </ItemGroup>
 
     <ItemGroup>
-        <ProjectReference Include="..\..\Infrastructure\Infrastructure.Configuration\Infrastructure.Configuration.csproj" />
+        <ProjectReference Include="..\..\Configuration\Configuration.csproj" />
         <ProjectReference Include="..\..\Shared\Shared.Application\Shared.Application.csproj" />
         <ProjectReference Include="..\Features.Emails.Templates\Features.Emails.Templates.csproj" />
         <ProjectReference Include="..\Features.Users\Features.Users.csproj" />

web/backend/Features/Features.Emails/Services/EmailDispatcher.cs

@@ -1,5 +1,5 @@
 using Features.Emails.Templates.Rendering;
-using Infrastructure.Configuration;
+using Configuration;
 using Microsoft.Extensions.Configuration;
 
 namespace Features.Emails.Services;

web/backend/Features/Features.Emails/Services/SmtpEmailProvider.cs

@@ -1,4 +1,4 @@
-using Infrastructure.Configuration;
+using Configuration;
 using MailKit.Net.Smtp;
 using MailKit.Security;
 using Microsoft.Extensions.Configuration;

web/backend/Features/Features.PhotoUpload/Features.PhotoUpload.csproj

@@ -22,7 +22,7 @@
         <ProjectReference Include="..\..\Domain\Domain.Entities\Domain.Entities.csproj" />
         <ProjectReference Include="..\..\Domain\Domain.Exceptions\Domain.Exceptions.csproj" />
         <ProjectReference Include="..\..\Database\Database.Connection\Database.Connection.csproj" />
-        <ProjectReference Include="..\..\Infrastructure\Infrastructure.Configuration\Infrastructure.Configuration.csproj" />
+        <ProjectReference Include="..\..\Configuration\Configuration.csproj" />
         <ProjectReference Include="..\..\Shared\Shared.Contracts\Shared.Contracts.csproj" />
         <ProjectReference Include="..\..\Shared\Shared.Application\Shared.Application.csproj" />
     </ItemGroup>

web/backend/Features/Features.PhotoUpload/Services/S3FileStorageProvider.cs

@@ -1,6 +1,6 @@
 using Amazon.S3;
 using Amazon.S3.Model;
-using Infrastructure.Configuration;
+using Configuration;
 using Microsoft.Extensions.Configuration;
 
 namespace Features.ImageUploads.Services;

web/backend/Features/Features.Users.Tests/Features.Users.Tests.csproj

@@ -22,6 +22,6 @@
 
     <ItemGroup>
         <ProjectReference Include="..\Features.Users\Features.Users.csproj" />
-        <ProjectReference Include="..\..\Infrastructure\Infrastructure.Configuration\Infrastructure.Configuration.csproj" />
+        <ProjectReference Include="..\..\Configuration\Configuration.csproj" />
     </ItemGroup>
 </Project>

web/backend/Features/Features.Users.Tests/Services/TokenServiceRefreshTests.cs

@@ -5,7 +5,7 @@ using Features.Users.Identity;
 using Features.Users.Services;
 using Features.Users.Tests.TestSupport;
 using FluentAssertions;
-using Infrastructure.Configuration;
+using Configuration;
 using Microsoft.AspNetCore.Identity;
 using Microsoft.Extensions.Configuration;
 using Moq;

web/backend/Features/Features.Users.Tests/Services/TokenServiceValidationTests.cs

@@ -4,7 +4,7 @@ using Domain.Exceptions;
 using Features.Users.Services;
 using Features.Users.Tests.TestSupport;
 using FluentAssertions;
-using Infrastructure.Configuration;
+using Configuration;
 using Microsoft.Extensions.Configuration;
 using Moq;
 

web/backend/Features/Features.Users/Features.Users.csproj

@@ -14,7 +14,7 @@
     <ItemGroup>
         <ProjectReference Include="..\..\Domain\Domain.Entities\Domain.Entities.csproj" />
         <ProjectReference Include="..\..\Domain\Domain.Exceptions\Domain.Exceptions.csproj" />
-        <ProjectReference Include="..\..\Infrastructure\Infrastructure.Configuration\Infrastructure.Configuration.csproj" />
+        <ProjectReference Include="..\..\Configuration\Configuration.csproj" />
         <ProjectReference Include="..\..\Database\Database.Connection\Database.Connection.csproj" />
         <ProjectReference Include="..\Features.PhotoUpload\Features.PhotoUpload.csproj" />
         <ProjectReference Include="..\..\Shared\Shared.Contracts\Shared.Contracts.csproj" />

web/backend/Features/Features.Users/Services/TokenService.cs

@@ -2,7 +2,7 @@ using System.IdentityModel.Tokens.Jwt;
 using System.Security.Claims;
 using Domain.Exceptions;
 using Features.Users.Identity;
-using Infrastructure.Configuration;
+using Configuration;
 using Microsoft.AspNetCore.Identity;
 using Microsoft.Extensions.Configuration;
 

web/backend/Shared/Shared.Application.Tests/Behaviors/UnhandledExceptionLoggingBehaviorTests.cs

@@ -0,0 +1,111 @@
+using FluentAssertions;
+using FluentValidation;
+using FluentValidation.Results;
+using MediatR;
+using Microsoft.Extensions.Logging;
+using Moq;
+using Shared.Application.Behaviors;
+
+namespace Shared.Application.Tests.Behaviors;
+
+public class UnhandledExceptionLoggingBehaviorTests
+{
+    private readonly Mock<
+        ILogger<UnhandledExceptionLoggingBehavior<TestRequest, TestResponse>>
+    > _loggerMock = new();
+
+    private UnhandledExceptionLoggingBehavior<TestRequest, TestResponse> CreateBehavior() =>
+        new(_loggerMock.Object);
+
+    [Fact]
+    public async Task Handle_WhenHandlerThrowsGenericException_LogsOnceAndRethrows()
+    {
+        UnhandledExceptionLoggingBehavior<TestRequest, TestResponse> behavior = CreateBehavior();
+        TestRequest request = new("aaron", "hunter2");
+        InvalidOperationException thrown = new("boom");
+        RequestHandlerDelegate<TestResponse> next = () => throw thrown;
+
+        Func<Task> act = async () => await behavior.Handle(request, next, CancellationToken.None);
+
+        (await act.Should().ThrowAsync<InvalidOperationException>())
+            .Which.Should()
+            .BeSameAs(thrown);
+        VerifyLogError(Times.Once());
+    }
+
+    [Fact]
+    public async Task Handle_WhenValidationExceptionThrown_DoesNotLogAndRethrows()
+    {
+        UnhandledExceptionLoggingBehavior<TestRequest, TestResponse> behavior = CreateBehavior();
+        TestRequest request = new("aaron", "hunter2");
+        ValidationException thrown = new([new ValidationFailure("Username", "is required")]);
+        RequestHandlerDelegate<TestResponse> next = () => throw thrown;
+
+        Func<Task> act = async () => await behavior.Handle(request, next, CancellationToken.None);
+
+        (await act.Should().ThrowAsync<ValidationException>()).Which.Should().BeSameAs(thrown);
+        VerifyLogError(Times.Never());
+    }
+
+    [Fact]
+    public async Task Handle_WhenHandlerSucceeds_DoesNotLogAndReturnsResponse()
+    {
+        UnhandledExceptionLoggingBehavior<TestRequest, TestResponse> behavior = CreateBehavior();
+        TestRequest request = new("aaron", "hunter2");
+        TestResponse response = new("ok");
+        RequestHandlerDelegate<TestResponse> next = () => Task.FromResult(response);
+
+        TestResponse result = await behavior.Handle(request, next, CancellationToken.None);
+
+        result.Should().BeSameAs(response);
+        VerifyLogError(Times.Never());
+    }
+
+    [Fact]
+    public async Task Handle_WhenHandlerThrows_RedactsSensitiveFieldsInLoggedPayload()
+    {
+        UnhandledExceptionLoggingBehavior<TestRequest, TestResponse> behavior = CreateBehavior();
+        TestRequest request = new("aaron", "hunter2");
+        RequestHandlerDelegate<TestResponse> next = () =>
+            throw new InvalidOperationException("boom");
+
+        Func<Task> act = async () => await behavior.Handle(request, next, CancellationToken.None);
+        await act.Should().ThrowAsync<InvalidOperationException>();
+
+        string loggedMessage = CaptureLoggedMessage();
+        loggedMessage.Should().Contain("aaron").And.NotContain("hunter2");
+    }
+
+    private void VerifyLogError(Times times) =>
+        _loggerMock.Verify(
+            l =>
+                l.Log(
+                    LogLevel.Error,
+                    It.IsAny<EventId>(),
+                    It.IsAny<It.IsAnyType>(),
+                    It.IsAny<Exception>(),
+                    It.IsAny<Func<It.IsAnyType, Exception?, string>>()
+                ),
+            times
+        );
+
+    private string CaptureLoggedMessage()
+    {
+        var invocation = _loggerMock
+            .Invocations.Where(i => i.Method.Name == nameof(ILogger.Log))
+            .Should()
+            .ContainSingle()
+            .Subject;
+
+        object state = invocation.Arguments[2];
+        object? exception = invocation.Arguments[3];
+        object formatter = invocation.Arguments[4];
+        System.Reflection.MethodInfo invokeMethod = formatter.GetType().GetMethod("Invoke")!;
+
+        return (string)invokeMethod.Invoke(formatter, [state, exception])!;
+    }
+}
+
+public record TestRequest(string Username, string Password) : IRequest<TestResponse>;
+
+public record TestResponse(string Value);

web/backend/Shared/Shared.Application.Tests/Shared.Application.Tests.csproj

@@ -0,0 +1,26 @@
+<Project Sdk="Microsoft.NET.Sdk">
+    <PropertyGroup>
+        <TargetFramework>net10.0</TargetFramework>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
+        <IsPackable>false</IsPackable>
+        <RootNamespace>Shared.Application.Tests</RootNamespace>
+    </PropertyGroup>
+
+    <ItemGroup>
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.0.1"/>
+        <PackageReference Include="xunit" Version="2.9.2"/>
+        <PackageReference Include="xunit.runner.visualstudio" Version="2.8.2"/>
+        <PackageReference Include="Moq" Version="4.20.72"/>
+        <PackageReference Include="FluentAssertions" Version="7.2.0"/>
+        <PackageReference Include="FluentValidation" Version="11.3.0"/>
+    </ItemGroup>
+
+    <ItemGroup>
+        <Using Include="Xunit"/>
+    </ItemGroup>
+
+    <ItemGroup>
+        <ProjectReference Include="..\Shared.Application\Shared.Application.csproj"/>
+    </ItemGroup>
+</Project>

web/backend/Shared/Shared.Application/Behaviors/UnhandledExceptionLoggingBehavior.cs

@@ -0,0 +1,86 @@
+using System.Text.Json;
+using System.Text.Json.Serialization.Metadata;
+using FluentValidation;
+using MediatR;
+using Microsoft.Extensions.Logging;
+
+namespace Shared.Application.Behaviors;
+
+/// <summary>
+///     MediatR pipeline behavior that logs unhandled exceptions together with the request type and
+///     payload, then rethrows them unchanged for <c>GlobalExceptionFilter</c> to map to a status code.
+/// </summary>
+public class UnhandledExceptionLoggingBehavior<TRequest, TResponse>(
+    ILogger<UnhandledExceptionLoggingBehavior<TRequest, TResponse>> logger
+) : IPipelineBehavior<TRequest, TResponse>
+    where TRequest : IRequest<TResponse>
+{
+    private static readonly string[] SensitiveFieldNames = ["password", "token"];
+
+    private static readonly JsonSerializerOptions SerializerOptions = new()
+    {
+        TypeInfoResolver = new DefaultJsonTypeInfoResolver
+        {
+            Modifiers = { RedactSensitiveProperties },
+        },
+    };
+
+    /// <inheritdoc/>
+    public async Task<TResponse> Handle(
+        TRequest request,
+        RequestHandlerDelegate<TResponse> next,
+        CancellationToken cancellationToken
+    )
+    {
+        try
+        {
+            return await next();
+        }
+        catch (ValidationException)
+        {
+            // Expected: ValidationBehavior already reports these as request errors, not incidents.
+            throw;
+        }
+        catch (Exception ex)
+        {
+            logger.LogError(
+                ex,
+                "Unhandled exception while processing {RequestName}: {RequestPayload}",
+                typeof(TRequest).Name,
+                Serialize(request)
+            );
+            throw;
+        }
+    }
+
+    private static string Serialize(TRequest request)
+    {
+        try
+        {
+            return JsonSerializer.Serialize(request, SerializerOptions);
+        }
+        catch (Exception)
+        {
+            return "<unable to serialize request payload>";
+        }
+    }
+
+    private static void RedactSensitiveProperties(JsonTypeInfo typeInfo)
+    {
+        if (typeInfo.Kind != JsonTypeInfoKind.Object)
+            return;
+
+        foreach (JsonPropertyInfo property in typeInfo.Properties)
+        {
+            if (property.PropertyType != typeof(string))
+                continue;
+
+            if (
+                SensitiveFieldNames.Any(name =>
+                    property.Name.Contains(name, StringComparison.OrdinalIgnoreCase)
+                )
+            )
+                property.Get = static _ => "***REDACTED***";
+        }
+    }
+}

web/backend/Shared/Shared.Application/Shared.Application.csproj

@@ -9,5 +9,6 @@
     <ItemGroup>
         <PackageReference Include="MediatR" Version="12.4.1" />
         <PackageReference Include="FluentValidation" Version="11.3.0" />
+        <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="10.0.1" />
     </ItemGroup>
 </Project>