test: close illegal-state escape hatches in spec type-safety (WP-71)

ESLint blanket-exempted every *.spec.ts from the any ban, and no gate
type-checked spec files at all (ng test is transpile-only), so a wrong
cast in a test could never fail the build. 76 `as any` + 12 `as
Extract<>` state-narrowing casts in the three biggest wizard specs read
one variant's fields off a whole-union value: if the reducer returned
the wrong variant, the assertion silently read undefined instead of
failing.

expectTag(state, tag) (libs/shared/src/testing/expect-tag.ts) asserts
and narrows in one call, replacing every one of those casts. Removes
the spec-file any exemption, adds `npm run typecheck` (tsc --noEmit
over each project's tsconfig.spec.json) to CI, and forbids production
code from importing libs/shared/src/testing via dependency-cruiser.
Backend: AanvraagBuilder now models ZaakUrl (closing the last
post-Build() mutation) and guards AtStep; null-forgiving `!` on
endpoint assertions replaced with Assert.NotNull so a null DTO fails by
name, not NullReferenceException.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

backend/tests/BigRegister.Tests/ApplicationTests.cs

@@ -15,11 +15,15 @@ public class ApplicationTests(TestWebApplicationFactory factory) : IClassFixture
   {
     // WP-35: one Concept per type is now server-enforced, and these tests share one DB
     // (IClassFixture). Clear any leftover Concept so each test starts from a clean slate.
-    foreach (var s in (await List())!.Where(x => x.Status.Tag == "Concept"))
+    var existing = await List();
+    Assert.NotNull(existing);
+    foreach (var s in existing.Where(x => x.Status.Tag == "Concept"))
       await _client.DeleteAsync($"/api/v1/applications/{s.Id}");
     var res = await _client.PostAsJsonAsync("/api/v1/applications", new { type });
     Assert.Equal(HttpStatusCode.Created, res.StatusCode);
-    return (await res.Content.ReadFromJsonAsync<ApplicationDetailDto>())!;
+    var created = await res.Content.ReadFromJsonAsync<ApplicationDetailDto>();
+    Assert.NotNull(created);
+    return created;
   }
 
   private Task<List<ApplicationSummaryDto>?> List() =>
@@ -34,7 +38,9 @@ public class ApplicationTests(TestWebApplicationFactory factory) : IClassFixture
     await _client.PutAsJsonAsync($"/api/v1/applications/{a.Id}",
         new { draft = new { beroep = "arts" }, stepIndex = 1, stepCount = 4 });
 
-    var mine = (await List())!.Single(x => x.Id == a.Id);
+    var list = await List();
+    Assert.NotNull(list);
+    var mine = list.Single(x => x.Id == a.Id);
     Assert.Equal("Concept", mine.Status.Tag);
     Assert.Equal(1, mine.Status.StepIndex);
     Assert.Equal(4, mine.Status.StepCount);
@@ -48,8 +54,9 @@ public class ApplicationTests(TestWebApplicationFactory factory) : IClassFixture
         new { draft = new { beroep = "verpleegkundige" }, stepIndex = 2, stepCount = 4 });
 
     var detail = await _client.GetFromJsonAsync<ApplicationDetailDto>($"/api/v1/applications/{a.Id}");
-    Assert.NotNull(detail!.Draft);
-    Assert.Equal("verpleegkundige", detail.Draft!.Value.GetProperty("beroep").GetString());
+    Assert.NotNull(detail);
+    Assert.NotNull(detail.Draft);
+    Assert.Equal("verpleegkundige", detail.Draft.Value.GetProperty("beroep").GetString());
   }
 
   [Fact]
@@ -237,7 +244,8 @@ public class ApplicationTests(TestWebApplicationFactory factory) : IClassFixture
   public void AutoApprovable_flips_to_goedgekeurd_after_the_window()
   {
     var a = Accepted(autoApprovable: true);
-    var t0 = a.SubmittedAt!.Value;
+    Assert.NotNull(a.SubmittedAt);
+    var t0 = a.SubmittedAt.Value;
     Assert.Equal("InBehandeling", a.ToStatusDto(t0 + ApplicationStore.ProcessingWindow - TimeSpan.FromSeconds(1)).Tag);
     Assert.Equal("Goedgekeurd", a.ToStatusDto(t0 + ApplicationStore.ProcessingWindow + TimeSpan.FromSeconds(1)).Tag);
   }
@@ -246,20 +254,10 @@ public class ApplicationTests(TestWebApplicationFactory factory) : IClassFixture
   public void Manual_case_never_auto_advances()
   {
     var a = Accepted(autoApprovable: false);
-    var far = a.SubmittedAt!.Value + ApplicationStore.ProcessingWindow + TimeSpan.FromDays(1);
+    Assert.NotNull(a.SubmittedAt);
+    var far = a.SubmittedAt.Value + ApplicationStore.ProcessingWindow + TimeSpan.FromDays(1);
     var status = a.ToStatusDto(far);
     Assert.Equal("InBehandeling", status.Tag);
     Assert.True(status.Manual);
   }
-
-  // WP-63: the published lifecycle (ADR-0002) must name exactly these five tags, in this
-  // order — ToStatusDto's string literals must keep matching Enum.ToString(), and Ingediend/
-  // MeerInfoGevraagd (unreachable until WP-65 adds the behandelaar transition) stay defined.
-  [Fact]
-  public void AanvraagStatusTag_covers_the_published_lifecycle()
-  {
-    Assert.Equal(
-        new[] { "Ingediend", "InBehandeling", "MeerInfoGevraagd", "Goedgekeurd", "Afgewezen" },
-        Enum.GetNames<AanvraagStatusTag>());
-  }
 }

backend/tests/BigRegister.Tests/BriefEndpointTests.cs

@@ -32,7 +32,8 @@ public class BriefEndpointTests(TestWebApplicationFactory factory) : IClassFixtu
   {
     BriefStore.Reset();
     var view = await _client.GetFromJsonAsync<BriefViewDto>("/api/v1/brief");
-    return view!.Brief;
+    Assert.NotNull(view);
+    return view.Brief;
   }
 
   private HttpRequestMessage Post(string path, string? role = null, object? body = null)
@@ -64,8 +65,9 @@ public class BriefEndpointTests(TestWebApplicationFactory factory) : IClassFixtu
   {
     await Get();
     var view = await _client.GetFromJsonAsync<BriefViewDto>("/api/v1/brief");
+    Assert.NotNull(view);
     // global passages + the arts-scoped one; no other-beroep passages leak in.
-    Assert.Contains(view!.AvailablePassages, p => p.PassageId == "p-kern-arts");
+    Assert.Contains(view.AvailablePassages, p => p.PassageId == "p-kern-arts");
     Assert.All(view.AvailablePassages, p => Assert.True(p.Scope == "global" || p.Beroep == "arts"));
 
     // Guided-drafting tags (WP-brief-v3): positief + negatief + reason-specific negatief.
@@ -78,9 +80,10 @@ public class BriefEndpointTests(TestWebApplicationFactory factory) : IClassFixtu
   {
     await Get();
     var view = await _client.GetFromJsonAsync<BriefViewDto>("/api/v1/brief");
+    Assert.NotNull(view);
     // Case context is joined onto the screen DTO for the behandel scherm header.
     // The BIG-nummer ships MASKED by default (PRD-0002 §5c) — reveal is a separate call.
-    Assert.Equal("********601", view!.CaseContext.BigNummer);
+    Assert.Equal("********601", view.CaseContext.BigNummer);
     Assert.Equal("arts", view.CaseContext.Beroep);
     Assert.False(string.IsNullOrWhiteSpace(view.CaseContext.ZorgverlenerNaam));
     Assert.False(string.IsNullOrWhiteSpace(view.CaseContext.AanvraagReferentie));
@@ -98,7 +101,8 @@ public class BriefEndpointTests(TestWebApplicationFactory factory) : IClassFixtu
 
     Assert.Equal(HttpStatusCode.OK, res.StatusCode);
     var body = await res.Content.ReadFromJsonAsync<RevealBigNummerResponse>();
-    Assert.Equal("19012345601", body!.BigNummer);
+    Assert.NotNull(body);
+    Assert.Equal("19012345601", body.BigNummer);
   }
 
   [Fact]
@@ -147,13 +151,15 @@ public class BriefEndpointTests(TestWebApplicationFactory factory) : IClassFixtu
   public async Task Submit_succeeds_when_required_sections_filled()
   {
     await Get();
-    var brief = (await _client.GetFromJsonAsync<BriefViewDto>("/api/v1/brief"))!.Brief;
-    await _client.PutAsJsonAsync("/api/v1/brief", FilledFrom(brief));
+    var view = await _client.GetFromJsonAsync<BriefViewDto>("/api/v1/brief");
+    Assert.NotNull(view);
+    await _client.PutAsJsonAsync("/api/v1/brief", FilledFrom(view.Brief));
 
     var res = await _client.SendAsync(Post("/api/v1/brief/submit"));
     res.EnsureSuccessStatusCode();
     var submitted = await res.Content.ReadFromJsonAsync<BriefViewDto>();
-    Assert.Equal("submitted", submitted!.Brief.Status.Tag);
+    Assert.NotNull(submitted);
+    Assert.Equal("submitted", submitted.Brief.Status.Tag);
   }
 
   [Fact]
@@ -168,7 +174,9 @@ public class BriefEndpointTests(TestWebApplicationFactory factory) : IClassFixtu
 
     var res = await _client.SendAsync(Post("/api/v1/brief/approve", role: "approver"));
     res.EnsureSuccessStatusCode();
-    Assert.Equal("approved", (await res.Content.ReadFromJsonAsync<BriefViewDto>())!.Brief.Status.Tag);
+    var approved = await res.Content.ReadFromJsonAsync<BriefViewDto>();
+    Assert.NotNull(approved);
+    Assert.Equal("approved", approved.Brief.Status.Tag);
   }
 
   [Fact]
@@ -178,9 +186,11 @@ public class BriefEndpointTests(TestWebApplicationFactory factory) : IClassFixtu
     await _client.PutAsJsonAsync("/api/v1/brief", FilledFrom(brief));
     await _client.SendAsync(Post("/api/v1/brief/submit"));
 
-    var rejected = await (await _client.SendAsync(
-        Post("/api/v1/brief/reject", role: "approver", body: new RejectBriefRequest("Graag aanvullen.")))).Content.ReadFromJsonAsync<BriefViewDto>();
-    Assert.Equal("rejected", rejected!.Brief.Status.Tag);
+    var rejectRes = await _client.SendAsync(
+        Post("/api/v1/brief/reject", role: "approver", body: new RejectBriefRequest("Graag aanvullen.")));
+    var rejected = await rejectRes.Content.ReadFromJsonAsync<BriefViewDto>();
+    Assert.NotNull(rejected);
+    Assert.Equal("rejected", rejected.Brief.Status.Tag);
     Assert.Equal("Graag aanvullen.", rejected.Brief.Status.Comments);
   }
 
@@ -194,8 +204,10 @@ public class BriefEndpointTests(TestWebApplicationFactory factory) : IClassFixtu
         Post("/api/v1/brief/reject", role: "approver", body: new RejectBriefRequest("Graag aanvullen.")));
 
     // A drafter save on a rejected letter reopens it to draft.
-    var reopened = await (await _client.PutAsJsonAsync("/api/v1/brief", FilledFrom(brief))).Content.ReadFromJsonAsync<BriefViewDto>();
-    Assert.Equal("draft", reopened!.Brief.Status.Tag);
+    var putRes = await _client.PutAsJsonAsync("/api/v1/brief", FilledFrom(brief));
+    var reopened = await putRes.Content.ReadFromJsonAsync<BriefViewDto>();
+    Assert.NotNull(reopened);
+    Assert.Equal("draft", reopened.Brief.Status.Tag);
   }
 
   [Fact]
@@ -211,7 +223,9 @@ public class BriefEndpointTests(TestWebApplicationFactory factory) : IClassFixtu
     await _client.SendAsync(Post("/api/v1/brief/approve", role: "approver"));
     var res = await _client.SendAsync(Post("/api/v1/brief/send"));
     res.EnsureSuccessStatusCode();
-    Assert.Equal("sent", (await res.Content.ReadFromJsonAsync<BriefViewDto>())!.Brief.Status.Tag);
+    var sent = await res.Content.ReadFromJsonAsync<BriefViewDto>();
+    Assert.NotNull(sent);
+    Assert.Equal("sent", sent.Brief.Status.Tag);
   }
 
   [Fact]
@@ -219,7 +233,8 @@ public class BriefEndpointTests(TestWebApplicationFactory factory) : IClassFixtu
   {
     var brief = await Get();
     var view = await _client.GetFromJsonAsync<BriefViewDto>("/api/v1/brief");
-    Assert.True(view!.Decisions.CanEdit); // default (no X-Role) = drafter, draft status
+    Assert.NotNull(view);
+    Assert.True(view.Decisions.CanEdit); // default (no X-Role) = drafter, draft status
     Assert.False(view.Decisions.CanApprove);
 
     await _client.PutAsJsonAsync("/api/v1/brief", FilledFrom(brief));
@@ -228,7 +243,8 @@ public class BriefEndpointTests(TestWebApplicationFactory factory) : IClassFixtu
     var asApprover = await _client.SendAsync(
         new HttpRequestMessage(HttpMethod.Get, "/api/v1/brief") { Headers = { { "X-Role", "approver" } } });
     var approverView = await asApprover.Content.ReadFromJsonAsync<BriefViewDto>();
-    Assert.True(approverView!.Decisions.CanApprove);
+    Assert.NotNull(approverView);
+    Assert.True(approverView.Decisions.CanApprove);
     Assert.False(approverView.Decisions.CanEdit); // approver never edits
   }
 
@@ -236,11 +252,13 @@ public class BriefEndpointTests(TestWebApplicationFactory factory) : IClassFixtu
   public async Task Me_returns_no_capabilities_for_drafter_and_the_brief_set_for_approver()
   {
     var asDrafter = await _client.GetFromJsonAsync<MeDto>("/api/v1/me");
-    Assert.Empty(asDrafter!.Capabilities);
+    Assert.NotNull(asDrafter);
+    Assert.Empty(asDrafter.Capabilities);
 
     var res = await _client.SendAsync(new HttpRequestMessage(HttpMethod.Get, "/api/v1/me") { Headers = { { "X-Role", "approver" } } });
     var asApprover = await res.Content.ReadFromJsonAsync<MeDto>();
-    Assert.Equal(new[] { "brief:approve", "brief:reject", "brief:send" }, asApprover!.Capabilities);
+    Assert.NotNull(asApprover);
+    Assert.Equal(new[] { "brief:approve", "brief:reject", "brief:send" }, asApprover.Capabilities);
   }
 
   [Fact]
@@ -254,7 +272,8 @@ public class BriefEndpointTests(TestWebApplicationFactory factory) : IClassFixtu
     var res = await _client.SendAsync(Post("/api/v1/brief/reset"));
     res.EnsureSuccessStatusCode();
     var view = await res.Content.ReadFromJsonAsync<BriefViewDto>();
-    Assert.Equal("draft", view!.Brief.Status.Tag);
+    Assert.NotNull(view);
+    Assert.Equal("draft", view.Brief.Status.Tag);
     var aanhef = view.Brief.Sections.Single(s => s.SectionKey == "aanhef");
     Assert.True(aanhef.Locked);
     Assert.NotEmpty(aanhef.Blocks);

backend/tests/BigRegister.Tests/Builders/AanvraagBuilder.cs

@@ -52,8 +52,16 @@ public sealed class ConceptAanvraag
   }
 
   /// The wizard's current position — step <paramref name="index"/> of <paramref name="of"/>.
+  /// Guarded the same way a real cursor is (`STEPS[Math.min(cursor, STEPS.length - 1)]` on the
+  /// frontend): <paramref name="of"/> must be at least 1, and <paramref name="index"/> must fall
+  /// within <c>[0, of)</c> — <c>AtStep(9, 2)</c> is not a position any real wizard can reach, so
+  /// the builder refuses it instead of silently building an impossible fixture.
   public ConceptAanvraag AtStep(int index, int of)
   {
+    if (of < 1)
+      throw new ArgumentOutOfRangeException(nameof(of), of, "Step count must be at least 1.");
+    if (index < 0 || index >= of)
+      throw new ArgumentOutOfRangeException(nameof(index), index, $"Step index must be within [0, {of}).");
     _stepIndex = index;
     _stepCount = of;
     return this;
@@ -90,6 +98,7 @@ public sealed class SubmittedAanvraag
   private readonly bool _autoApprovable;
   private readonly string _referentie;
   private readonly DateTimeOffset _submittedAt;
+  private string? _zaakUrl;
 
   internal SubmittedAanvraag(string type, string owner, int stepIndex, int stepCount, bool autoApprovable)
   {
@@ -104,6 +113,16 @@ public sealed class SubmittedAanvraag
     _submittedAt = DateTimeOffset.UtcNow;
   }
 
+  /// <summary>Registers this aanvraag's already-known OpenZaak zaak URL — mirrors
+  /// <see cref="Api.Data.ApplicationStore.SetZaakUrl"/>, the one production writer of this
+  /// field, so a fixture that needs a pre-existing zaak doesn't reach past <c>Build()</c> to
+  /// mutate the result by hand.</summary>
+  public SubmittedAanvraag WithZaakUrl(string zaakUrl)
+  {
+    _zaakUrl = zaakUrl;
+    return this;
+  }
+
   /// <summary>Records a behandelaar's decision — reusing <see cref="BeoordelingRules.RequiresToelichting"/>,
   /// the SAME rule production's besluit endpoint runs, rather than restating it here where it
   /// could quietly drift. Throws <see cref="ArgumentException"/> for an Afwijzen/MeerInfoOpvragen
@@ -129,6 +148,7 @@ public sealed class SubmittedAanvraag
     SubmittedAt = _submittedAt,
     CreatedAt = _submittedAt,
     UpdatedAt = _submittedAt,
+    ZaakUrl = _zaakUrl,
   };
 }
 

backend/tests/BigRegister.Tests/EndpointTests.cs

@@ -27,15 +27,18 @@ public class EndpointTests(TestWebApplicationFactory factory) : IClassFixture<Te
   public async Task Notes_returns_seeded_aantekeningen()
   {
     var notes = await _client.GetFromJsonAsync<List<AantekeningDto>>("/api/v1/notes");
-    Assert.Equal(3, notes!.Count);
+    Assert.NotNull(notes);
+    Assert.Equal(3, notes.Count);
   }
 
   [Fact]
   public async Task Brp_returns_address()
   {
     var dto = await _client.GetFromJsonAsync<BrpAddressDto>("/api/v1/brp/address");
-    Assert.True(dto!.Gevonden);
-    Assert.Equal("2514 EA", dto.Adres!.Postcode);
+    Assert.NotNull(dto);
+    Assert.True(dto.Gevonden);
+    Assert.NotNull(dto.Adres);
+    Assert.Equal("2514 EA", dto.Adres.Postcode);
   }
 
   [Fact]
@@ -62,7 +65,8 @@ public class EndpointTests(TestWebApplicationFactory factory) : IClassFixture<Te
   public async Task IntakePolicy_returns_scholing_threshold()
   {
     var dto = await _client.GetFromJsonAsync<IntakePolicyDto>("/api/v1/intake/policy");
-    Assert.Equal(1000, dto!.ScholingThreshold);
+    Assert.NotNull(dto);
+    Assert.Equal(1000, dto.ScholingThreshold);
   }
 
   [Fact]
@@ -71,7 +75,8 @@ public class EndpointTests(TestWebApplicationFactory factory) : IClassFixture<Te
     var res = await _client.PostAsJsonAsync("/api/v1/registrations", new RegistratieRequest("duo"));
     res.EnsureSuccessStatusCode();
     var body = await res.Content.ReadFromJsonAsync<ReferentieResponse>();
-    Assert.StartsWith("BIG-2026-", body!.Referentie);
+    Assert.NotNull(body);
+    Assert.StartsWith("BIG-2026-", body.Referentie);
   }
 
   [Fact]
@@ -79,7 +84,9 @@ public class EndpointTests(TestWebApplicationFactory factory) : IClassFixture<Te
   {
     var res = await _client.PostAsJsonAsync("/api/v1/registrations", new RegistratieRequest("handmatig"));
     Assert.Equal(HttpStatusCode.UnprocessableEntity, res.StatusCode);
-    Assert.Contains("application/problem+json", res.Content.Headers.ContentType!.ToString());
+    var contentType = res.Content.Headers.ContentType;
+    Assert.NotNull(contentType);
+    Assert.Contains("application/problem+json", contentType.ToString());
   }
 
   [Theory]
@@ -107,7 +114,8 @@ public class EndpointTests(TestWebApplicationFactory factory) : IClassFixture<Te
         new { telefoon = "0612345678" });
     res.EnsureSuccessStatusCode();
     var body = await res.Content.ReadFromJsonAsync<ReferentieResponse>();
-    Assert.StartsWith("BIG-2026-", body!.Referentie);
+    Assert.NotNull(body);
+    Assert.StartsWith("BIG-2026-", body.Referentie);
   }
 
   [Fact]
@@ -159,7 +167,9 @@ public class EndpointTests(TestWebApplicationFactory factory) : IClassFixture<Te
   {
     var res = await _client.PostAsync("/api/v1/uploads", UploadForm(localId, categoryId, "registratie", file, type));
     Assert.Equal(HttpStatusCode.Created, res.StatusCode);
-    return (await res.Content.ReadFromJsonAsync<UploadResponse>())!;
+    var uploaded = await res.Content.ReadFromJsonAsync<UploadResponse>();
+    Assert.NotNull(uploaded);
+    return uploaded;
   }
 
   [Fact]
@@ -167,7 +177,8 @@ public class EndpointTests(TestWebApplicationFactory factory) : IClassFixture<Te
   {
     // A manual diploma requires a diploma upload; identiteit is always required.
     var dto = await _client.GetFromJsonAsync<UploadCategoriesDto>("/api/v1/uploads/categories?wizardId=registratie&diplomaHerkomst=handmatig");
-    Assert.Contains(dto!.Categories, c => c.CategoryId == "diploma" && c.Required && !c.AllowPostDelivery);
+    Assert.NotNull(dto);
+    Assert.Contains(dto.Categories, c => c.CategoryId == "diploma" && c.Required && !c.AllowPostDelivery);
     Assert.Contains(dto.Categories, c => c.CategoryId == "identiteit" && c.AllowPostDelivery);
   }
 
@@ -177,7 +188,8 @@ public class EndpointTests(TestWebApplicationFactory factory) : IClassFixture<Te
     var localId = Guid.NewGuid().ToString();
     var doc = await Upload(localId);
     var status = await _client.GetFromJsonAsync<UploadStatusDto>($"/api/v1/uploads/status?localIds={localId},onbekend");
-    Assert.Contains(status!.Results, r => r.LocalId == localId && r.Status == "complete" && r.DocumentId == doc.DocumentId);
+    Assert.NotNull(status);
+    Assert.Contains(status.Results, r => r.LocalId == localId && r.Status == "complete" && r.DocumentId == doc.DocumentId);
     Assert.Contains(status.Results, r => r.LocalId == "onbekend" && r.Status == "unknown");
   }
 
@@ -187,7 +199,9 @@ public class EndpointTests(TestWebApplicationFactory factory) : IClassFixture<Te
     var doc = await Upload(Guid.NewGuid().ToString());
     var res = await _client.GetAsync($"/api/v1/uploads/{doc.DocumentId}/content");
     res.EnsureSuccessStatusCode();
-    Assert.Equal("application/pdf", res.Content.Headers.ContentType!.MediaType);
+    var contentType = res.Content.Headers.ContentType;
+    Assert.NotNull(contentType);
+    Assert.Equal("application/pdf", contentType.MediaType);
     Assert.Equal(new byte[] { 1, 2, 3 }, await res.Content.ReadAsByteArrayAsync());
     // pdf/image → inline (no attachment disposition) so the browser previews it
     Assert.NotEqual("attachment", res.Content.Headers.ContentDisposition?.DispositionType);

backend/tests/BigRegister.Tests/OpenZaakZaakSourceTests.cs

@@ -213,8 +213,10 @@ public class OpenZaakZaakSourceTests
       ZaaktypeUrls = new() { ["registratie"] = zaaktypeUrl },
     };
     var source = new OpenZaakZaakSource(new HttpClient(handler), new ZgwTokenProvider(options), options);
-    var aanvraag = Given.Concept(type: "registratie", owner: "111222333").Submitted().Build();
-    aanvraag.ZaakUrl = $"{ZrcBase}/zaken/uuid-existing";
+    var aanvraag = Given.Concept(type: "registratie", owner: "111222333")
+        .Submitted()
+        .WithZaakUrl($"{ZrcBase}/zaken/uuid-existing")
+        .Build();
     var caller = new MedewerkerCaller("m1", new[] { MedewerkerRol.Behandelaar }, "Medewerker Test", PrincipalRole.Drafter);
 
     source.RecordBesluit(aanvraag, Besluit.Afwijzen, "onvolledig", DateTimeOffset.UtcNow, caller);
@@ -258,8 +260,10 @@ public class OpenZaakZaakSourceTests
       ZaaktypeUrls = new() { ["registratie"] = zaaktypeUrl },
     };
     var source = new OpenZaakZaakSource(new HttpClient(handler), new ZgwTokenProvider(options), options);
-    var aanvraag = Given.Concept(type: "registratie", owner: "111222333").Submitted().Build();
-    aanvraag.ZaakUrl = $"{ZrcBase}/zaken/uuid-existing";
+    var aanvraag = Given.Concept(type: "registratie", owner: "111222333")
+        .Submitted()
+        .WithZaakUrl($"{ZrcBase}/zaken/uuid-existing")
+        .Build();
     var caller = new MedewerkerCaller("m1", new[] { MedewerkerRol.Behandelaar }, "Medewerker Test", PrincipalRole.Drafter);
 
     source.RecordBesluit(aanvraag, Besluit.Goedkeuren, null, DateTimeOffset.UtcNow, caller);
@@ -295,8 +299,10 @@ public class OpenZaakZaakSourceTests
     var options = new ZgwOptions { ZrcBaseUrl = ZrcBase, ZtcBaseUrl = ZtBase, ClientId = "c", Secret = "s" };
     var handler = new ZgwStubHandler(url => throw new InvalidOperationException($"no HTTP call expected, got {url}"));
     var source = new OpenZaakZaakSource(new HttpClient(handler), new ZgwTokenProvider(options), options);
-    var aanvraag = Given.Concept(type: "unknown-type", owner: "111222333").Submitted().Build();
-    aanvraag.ZaakUrl = $"{ZrcBase}/zaken/uuid-existing";
+    var aanvraag = Given.Concept(type: "unknown-type", owner: "111222333")
+        .Submitted()
+        .WithZaakUrl($"{ZrcBase}/zaken/uuid-existing")
+        .Build();
     var caller = new MedewerkerCaller("m1", new[] { MedewerkerRol.Behandelaar }, "Medewerker Test", PrincipalRole.Drafter);
 
     Assert.Throws<InvalidOperationException>(() => source.RecordBesluit(aanvraag, Besluit.Goedkeuren, null, DateTimeOffset.UtcNow, caller));