Initial curated itworx-knowledge-hub source from 3b1751d0d9dee551aa6994eee0093704dc334817

tests/backend/ItWorx.KnowledgeHub.IntegrationTests/Knowledge/PageConcurrencyTests.cs

@@ -0,0 +1,85 @@
+using System.Net;
+using System.Net.Http.Json;
+using ItWorx.KnowledgeHub.Contracts.Knowledge;
+using ItWorx.KnowledgeHub.IntegrationTests.Infrastructure;
+
+namespace ItWorx.KnowledgeHub.IntegrationTests.Knowledge;
+
+/// <summary>Concurrent edits must produce an explicit conflict, never a silently lost
+/// update (docs/27-acceptance-matrix.md, M2-A05).</summary>
+[Collection(PostgresTestGroup.Name)]
+public sealed class PageConcurrencyTests(PostgresContainerFixture postgres) : OwnerSetupTestBase(postgres)
+{
+    [Fact]
+    public async Task Publishing_with_a_stale_ETag_is_rejected_and_never_overwrites_the_newer_revision()
+    {
+        using var client = Factory.CreateClient();
+        await SetupHelper.LoginAsync(client, OwnerEmail, OwnerPassword);
+
+        var createResponse = await SetupHelper.PostWithCsrfAsync(
+            client, "/api/v1/pages", new CreatePageRequest(null, "Conflicttest", "WikiPage", "Origineel", null));
+        var page = await createResponse.Content.ReadFromJsonAsync<PageDetail>();
+        Assert.NotNull(page);
+        var staleETag = page.ETag;
+
+        // Session A publishes successfully first, advancing the ETag.
+        var firstEdit = await SetupHelper.PutWithCsrfAsync(
+            client,
+            $"/api/v1/pages/{page.Id}",
+            new UpdatePageRequest("Titel van A", "Inhoud van A", "WikiPage", "Active", null),
+            staleETag);
+        Assert.Equal(HttpStatusCode.OK, firstEdit.StatusCode);
+
+        // Session B still holds the original (now stale) ETag from before A's publish.
+        var secondEdit = await SetupHelper.PutWithCsrfAsync(
+            client,
+            $"/api/v1/pages/{page.Id}",
+            new UpdatePageRequest("Titel van B", "Inhoud van B", "WikiPage", "Active", null),
+            staleETag);
+
+        Assert.Equal(HttpStatusCode.PreconditionFailed, secondEdit.StatusCode);
+
+        // The current server state is still A's edit, not silently overwritten by B.
+        var current = await client.GetFromJsonAsync<PageDetail>($"/api/v1/pages/{page.Id}");
+        Assert.NotNull(current);
+        Assert.Equal("Titel van A", current.Title);
+    }
+
+    [Fact]
+    public async Task Simultaneous_publishes_return_one_success_and_only_explicit_conflicts()
+    {
+        using var creator = Factory.CreateClient();
+        await SetupHelper.LoginAsync(creator, OwnerEmail, OwnerPassword);
+
+        var createResponse = await SetupHelper.PostWithCsrfAsync(
+            creator, "/api/v1/pages", new CreatePageRequest(null, "Gelijktijdige conflicttest", "WikiPage", "Origineel", null));
+        var page = await createResponse.Content.ReadFromJsonAsync<PageDetail>();
+        Assert.NotNull(page);
+
+        var clients = Enumerable.Range(0, 8).Select(_ => Factory.CreateClient()).ToArray();
+        try
+        {
+            await Task.WhenAll(clients.Select(client => SetupHelper.LoginAsync(client, OwnerEmail, OwnerPassword)));
+            var responses = await Task.WhenAll(clients.Select((client, index) =>
+                SetupHelper.PutWithCsrfAsync(
+                    client,
+                    $"/api/v1/pages/{page.Id}",
+                    new UpdatePageRequest($"Kandidaat {index}", $"Inhoud {index}", "WikiPage", "Active", null),
+                    page.ETag)));
+
+            Assert.Single(responses, response => response.StatusCode == HttpStatusCode.OK);
+            Assert.Equal(7, responses.Count(response => response.StatusCode == HttpStatusCode.PreconditionFailed));
+        }
+        finally
+        {
+            foreach (var client in clients)
+            {
+                client.Dispose();
+            }
+        }
+
+        var revisions = await creator.GetFromJsonAsync<IReadOnlyList<PageRevisionSummary>>($"/api/v1/pages/{page.Id}/revisions");
+        Assert.NotNull(revisions);
+        Assert.Equal(2, revisions.Count);
+    }
+}