src/api/SIGCM2.Api/Filters/ExceptionFilter.cs

@@ -267,6 +267,18 @@ public sealed class ExceptionFilter : IExceptionFilter
                 context.ExceptionHandled = true;
                 break;
 
+            case RubroConProductosActivosException rubroProductosEx:
+                context.Result = new ObjectResult(new
+                {
+                    error = "rubro_con_productos_activos",
+                    message = rubroProductosEx.Message
+                })
+                {
+                    StatusCode = StatusCodes.Status409Conflict
+                };
+                context.ExceptionHandled = true;
+                break;
+
             // ADM-001: Medio exceptions
             case MedioCodigoDuplicadoException medioCodDupEx:
                 context.Result = new ObjectResult(new

tests/SIGCM2.Api.Tests/ProductTypes/ProductTypesControllerTests.cs

@@ -327,4 +327,7 @@ file sealed class AlwaysInUseProductQueryRepository : IProductQueryRepository
 {
     public Task<bool> ExistsActiveByProductTypeAsync(int productTypeId, CancellationToken ct = default)
         => Task.FromResult(true);
+
+    public Task<int> CountActiveByRubroAsync(int rubroId, CancellationToken ct = default)
+        => Task.FromResult(0);
 }

tests/SIGCM2.Api.Tests/Rubros/RubrosDeactivateGuardTests.cs

@@ -0,0 +1,160 @@
+using System.Net;
+using System.Net.Http.Headers;
+using System.Net.Http.Json;
+using System.Text.Json;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.Filters;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.DependencyInjection.Extensions;
+using Microsoft.Extensions.Logging.Abstractions;
+using SIGCM2.Api.Filters;
+using SIGCM2.Application.Abstractions.Persistence;
+using SIGCM2.Domain.Exceptions;
+using SIGCM2.TestSupport;
+
+namespace SIGCM2.Api.Tests.Rubros;
+
+/// <summary>
+/// Issue #41 — DeactivateRubroCommandHandler guard contra Products activos.
+///
+/// Unit tests: ExceptionFilter mapping for RubroConProductosActivosException → 409.
+/// E2E: DELETE /api/v1/admin/rubros/{id} with stub IProductQueryRepository returning count > 0 → 409.
+/// </summary>
+[Collection("ApiIntegration")]
+public sealed class RubrosDeactivateGuardTests : IAsyncLifetime
+{
+    private const string AdminEndpoint = "/api/v1/admin/rubros";
+    private const string AdminUsername = "admin";
+    private const string AdminPassword = "@Diego550@";
+
+    private readonly TestWebAppFactory _factory;
+    private readonly HttpClient _client;
+
+    public RubrosDeactivateGuardTests(TestWebAppFactory factory)
+    {
+        _factory = factory;
+        _client = factory.CreateClient();
+    }
+
+    public Task InitializeAsync() => Task.CompletedTask;
+    public Task DisposeAsync() => Task.CompletedTask;
+
+    // ── ExceptionFilter unit test (no DB, no HTTP) ────────────────────────────
+
+    [Fact]
+    public void ExceptionFilter_MapsRubroConProductosActivos_To409()
+    {
+        var filter = new ExceptionFilter(NullLogger<ExceptionFilter>.Instance);
+        var httpContext = new Microsoft.AspNetCore.Http.DefaultHttpContext();
+        var routeData = new Microsoft.AspNetCore.Routing.RouteData();
+        var actionDescriptor = new Microsoft.AspNetCore.Mvc.Abstractions.ActionDescriptor();
+        var modelState = new Microsoft.AspNetCore.Mvc.ModelBinding.ModelStateDictionary();
+        var actionContext = new ActionContext(httpContext, routeData, actionDescriptor, modelState);
+        var ctx = new ExceptionContext(actionContext, new List<IFilterMetadata>())
+        {
+            Exception = new RubroConProductosActivosException(rubroId: 5, productosActivosCount: 2)
+        };
+
+        filter.OnException(ctx);
+
+        var result = Assert.IsType<ObjectResult>(ctx.Result);
+        Assert.Equal(StatusCodes.Status409Conflict, result.StatusCode);
+        var json = System.Text.Json.JsonSerializer.Serialize(result.Value);
+        Assert.Contains("rubro_con_productos_activos", json);
+    }
+
+    // ── E2E: DELETE with stub reporting active products → 409 ─────────────────
+
+    /// <summary>
+    /// Verifies the 409 guard path end-to-end via a per-test DI override: injects a stub
+    /// IProductQueryRepository that reports the Rubro has 2 active products,
+    /// so no real Product row needs to exist in the database (issue #36 DI override pattern).
+    /// </summary>
+    [Fact]
+    public async Task DeactivateRubro_WhenHasActiveProducts_Returns409WithErrorCode()
+    {
+        // Arrange: get admin token from shared client (same DB)
+        var token = await GetAdminTokenAsync();
+
+        // Create a real Rubro to have a valid id to deactivate
+        using var createReq = new HttpRequestMessage(HttpMethod.Post, AdminEndpoint);
+        createReq.Headers.Authorization = new AuthenticationHeaderValue("Bearer", token);
+        createReq.Content = JsonContent.Create(new
+        {
+            nombre = $"Rubro_Guard41_{Guid.NewGuid():N}"[..30],
+            parentId = (int?)null,
+        });
+        var createResp = await _client.SendAsync(createReq);
+        Assert.Equal(HttpStatusCode.Created, createResp.StatusCode);
+        var created = await createResp.Content.ReadFromJsonAsync<JsonElement>();
+        var rubroId = created.GetProperty("id").GetInt32();
+
+        try
+        {
+            // Override IProductQueryRepository to report 2 active products for any rubroId
+            using var overrideClient = _factory.CreateClientWithOverrides(services =>
+            {
+                services.RemoveAll<IProductQueryRepository>();
+                services.AddScoped<IProductQueryRepository>(_ => new StubProductQueryRepository(activeCount: 2));
+            });
+
+            var deleteReq = new HttpRequestMessage(HttpMethod.Delete, $"{AdminEndpoint}/{rubroId}");
+            deleteReq.Headers.Authorization = new AuthenticationHeaderValue("Bearer", token);
+            var resp = await overrideClient.SendAsync(deleteReq);
+
+            Assert.Equal(HttpStatusCode.Conflict, resp.StatusCode);
+            var body = await resp.Content.ReadFromJsonAsync<JsonElement>();
+            Assert.Equal("rubro_con_productos_activos", body.GetProperty("error").GetString());
+        }
+        finally
+        {
+            await DeleteRubroDirectAsync(rubroId);
+        }
+    }
+
+    // ── Helpers ───────────────────────────────────────────────────────────────
+
+    private async Task<string> GetAdminTokenAsync()
+    {
+        var response = await _client.PostAsJsonAsync("/api/v1/auth/login", new
+        {
+            username = AdminUsername,
+            password = AdminPassword
+        });
+        response.EnsureSuccessStatusCode();
+        var json = await response.Content.ReadFromJsonAsync<JsonElement>();
+        return json.GetProperty("accessToken").GetString()!;
+    }
+
+    private static async Task DeleteRubroDirectAsync(int id)
+    {
+        await using var conn = new Microsoft.Data.SqlClient.SqlConnection(TestConnectionStrings.ApiTestDb);
+        await conn.OpenAsync();
+        await Dapper.SqlMapper.ExecuteAsync(conn, "ALTER TABLE dbo.Rubro SET (SYSTEM_VERSIONING = OFF)");
+        await Dapper.SqlMapper.ExecuteAsync(conn, "DELETE FROM dbo.Rubro_History WHERE Id = @Id", new { Id = id });
+        await Dapper.SqlMapper.ExecuteAsync(conn, "DELETE FROM dbo.Rubro WHERE Id = @Id", new { Id = id });
+        await Dapper.SqlMapper.ExecuteAsync(conn,
+            "ALTER TABLE dbo.Rubro SET (SYSTEM_VERSIONING = ON (HISTORY_TABLE = dbo.Rubro_History, HISTORY_RETENTION_PERIOD = 10 YEARS))");
+    }
+}
+
+/// <summary>
+/// Stub: always reports a fixed count of active products for any rubroId.
+/// Used by RubrosDeactivateGuardTests to verify the 409 guard without seeding real Product rows.
+/// </summary>
+file sealed class StubProductQueryRepository : IProductQueryRepository
+{
+    private readonly int _activeCount;
+
+    public StubProductQueryRepository(int activeCount)
+    {
+        _activeCount = activeCount;
+    }
+
+    public Task<bool> ExistsActiveByProductTypeAsync(int productTypeId, CancellationToken ct = default)
+        => Task.FromResult(false);
+
+    public Task<int> CountActiveByRubroAsync(int rubroId, CancellationToken ct = default)
+        => Task.FromResult(_activeCount);
+}