test(bff): /behandel/registrations/{id}/decide auth + forwarding + besluit validation (refs #13)

Red — the decide endpoint does not exist yet.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

services/bff/Bff.Api/DownstreamClients.cs

@@ -24,6 +24,9 @@ public interface IDomainClient
 
     /// <summary>The behandelaar's werkbak — registrations awaiting beoordeling.</summary>
     Task<IReadOnlyList<WerkbakItem>> GetWerkbakAsync(CancellationToken ct = default);
+
+    /// <summary>Apply a behandelaar's decision (<c>goedkeuren</c>/<c>afwijzen</c>) to a registration.</summary>
+    Task DecideAsync(string registrationId, string besluit, CancellationToken ct = default);
 }
 
 /// <summary>Port to the read projection.</summary>
@@ -47,6 +50,13 @@ public sealed class DomainClient(HttpClient http) : IDomainClient
     public async Task<IReadOnlyList<WerkbakItem>> GetWerkbakAsync(CancellationToken ct = default)
         => await http.GetFromJsonAsync<List<WerkbakItem>>("behandel/werkbak", ct) ?? [];
 
+    public async Task DecideAsync(string registrationId, string besluit, CancellationToken ct = default)
+    {
+        using var response = await http.PostAsJsonAsync(
+            $"registrations/{registrationId}/decide", new { besluit }, ct);
+        response.EnsureSuccessStatusCode();
+    }
+
     private sealed record DomainResponse(string RegistrationId, string Status, string? ZaakUrl);
 }
 

services/bff/Bff.Tests/BehandelEndpointTests.cs

@@ -54,4 +54,61 @@ public class BehandelEndpointTests
         Assert.Equal("reg-1", item.RegistrationId);
         Assert.Equal("123456782", item.Bsn);
     }
+
+    private static HttpRequestMessage Decide(string? bearer, string id = "reg-1", string besluit = "goedkeuren")
+    {
+        var request = new HttpRequestMessage(HttpMethod.Post, $"/behandel/registrations/{id}/decide")
+        {
+            Content = JsonContent.Create(new { besluit }),
+        };
+        if (bearer is not null)
+            request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", bearer);
+        return request;
+    }
+
+    [Fact]
+    public async Task Rejects_a_decision_without_a_token()
+    {
+        using var factory = new BffFactory();
+
+        var response = await factory.CreateClient().SendAsync(Decide(bearer: null));
+
+        Assert.Equal(HttpStatusCode.Unauthorized, response.StatusCode);
+        Assert.Null(factory.Domain.Decided);
+    }
+
+    [Fact]
+    public async Task Rejects_a_decision_from_a_medewerker_without_the_behandelaar_role()
+    {
+        using var factory = new BffFactory();
+
+        var response = await factory.CreateClient().SendAsync(Decide(TestTokens.Medewerker("teamlead")));
+
+        Assert.Equal(HttpStatusCode.Forbidden, response.StatusCode);
+        Assert.Null(factory.Domain.Decided);
+    }
+
+    [Fact]
+    public async Task Forwards_a_behandelaar_decision_to_the_domain()
+    {
+        using var factory = new BffFactory();
+
+        var response = await factory.CreateClient()
+            .SendAsync(Decide(TestTokens.Medewerker("behandelaar"), id: "reg-42", besluit: "afwijzen"));
+
+        Assert.Equal(HttpStatusCode.NoContent, response.StatusCode);
+        Assert.Equal(("reg-42", "afwijzen"), factory.Domain.Decided);
+    }
+
+    [Fact]
+    public async Task Rejects_an_unknown_besluit_without_calling_the_domain()
+    {
+        using var factory = new BffFactory();
+
+        var response = await factory.CreateClient()
+            .SendAsync(Decide(TestTokens.Medewerker("behandelaar"), besluit: "misschien"));
+
+        Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
+        Assert.Null(factory.Domain.Decided);
+    }
 }

services/bff/Bff.Tests/BffFactory.cs

@@ -82,8 +82,16 @@ internal sealed class FakeDomainClient : IDomainClient
         return Task.FromResult(Result);
     }
 
+    public (string RegistrationId, string Besluit)? Decided { get; private set; }
+
     public Task<IReadOnlyList<WerkbakItem>> GetWerkbakAsync(CancellationToken ct = default)
         => Task.FromResult<IReadOnlyList<WerkbakItem>>(Werkbak);
+
+    public Task DecideAsync(string registrationId, string besluit, CancellationToken ct = default)
+    {
+        Decided = (registrationId, besluit);
+        return Task.CompletedTask;
+    }
 }
 
 /// <summary>Serves a configurable set of projection rows.</summary>