code REORG, pour partage pkg version entre app et tests

src/PostIt/PostIt.Tests/MainPageSaveTests.cs

@@ -0,0 +1,88 @@
+using Avalonia.Controls;
+using Avalonia.Headless.XUnit;
+using Avalonia.VisualTree;
+using Yavsc.Blogspot;
+using Yavsc.Api.Client;
+using PostIt.ViewModels;
+using PostIt.Views;
+namespace PostIt.Tests;
+
+/// <summary>
+/// Headless UI tests for the "Save" flow in <see cref="MainPage"/>.
+/// The pattern is the one <c>SessionStatusBannerTests</c>
+/// established: <c>[AvaloniaFact]</c>, a <see cref="Window"/>
+/// hosting the page (via a <see cref="Frame"/> because
+/// <c>MainPage</c> is a <c>ContentPage</c>), then drive the
+/// controls through their public surface and assert on what
+/// <see cref="RecordingYavscApiClient"/> saw go on the wire.
+///
+/// <para>The bug we are pinning: the title <c>TextBox</c> is
+/// currently <c>{Binding SelectedPost.Title, Mode=TwoWay}</c>.
+/// When <c>SelectedPost is null</c> (i.e. the user has not yet
+/// clicked an item in the posts list — which is the only state
+/// in which a brand-new post can be created), the binding has
+/// no target and the user's keystrokes are silently dropped.
+/// Clicking "Save" then routes to the VM branch
+/// <c>if (SelectedPost is null) { new BlogPostDto { Title = string.Empty, ... } }</c>
+/// which the controller rejects with 400 "The Title field is
+/// required." This test fails on that branch today and will
+/// pass once the VM owns a dedicated <c>Title</c>/<c>Article</c>
+/// buffer that the XAML binds to and the Save command consumes.</para>
+/// </summary>
+public class MainPageSaveTests
+{
+    [AvaloniaFact]
+    public async Task Typing_a_title_then_clicking_Save_sends_that_title_in_the_post_body()
+    {
+        // Arrange: VM with a recording API client, mounted in a
+        // headless window via a Frame (MainPage is a ContentPage,
+        // not a Control, so it needs a navigation host).
+        var recorder = new CallRecorder();
+        var api = new RecordingYavscApiClient(recorder);
+        var blog = new BlogApiClient(api, "http://localhost/");
+        var viewModel = new MainPageViewModel(blog);
+
+        var page = new MainPage { DataContext = viewModel };
+        // MainPage is a ContentPage (a Page, not a Control), so it
+        // must be hosted in a navigation surface. The production
+        // MainWindow.axaml uses NavigationPage, and the API is the
+        // same one App.axaml.cs drives at boot (PushAsync, fire-
+        // and-forget in prod because the page is the top of the
+        // stack immediately).
+        var nav = new NavigationPage();
+        _ = nav.PushAsync(page);
+        var window = new Window { Content = nav };
+        window.Show();
+
+        // Act: type a title into the editor's TextBox without
+        // first selecting a post in the list — the only state in
+        // which a new post can be created. Then click Save.
+        var titleBox = window.GetVisualDescendants()
+            .OfType<TextBox>()
+            .First(t => t.PlaceholderText == "Title");
+        const string typed = "Mon premier billet";
+        titleBox.Text = typed;
+
+        var saveButton = window.GetVisualDescendants()
+            .OfType<Button>()
+            .Single(b => b.Content as string == "Save");
+        saveButton.Command!.Execute(null);
+
+        // The Save command is async (RelayCommand over Task) but
+        // ExecuteAsync would await; the sync Execute enqueues the
+        // task on the dispatcher. Give the dispatcher a chance to
+        // run so the awaited CallAsync has actually fired before
+        // we inspect the recorder.
+        await Task.Delay(200);
+
+        // Assert: the first POST to "blog" carried a BlogPostDto
+        // whose Title is exactly what the user typed. The bug
+        // fails this assertion with Title == string.Empty.
+        Assert.NotEmpty(recorder.Calls);
+        var (method, path, body) = recorder.FirstCall;
+        Assert.Equal(HttpMethod.Post, method);
+        Assert.Equal("blog", path);
+        var sent = Assert.IsType<BlogPostDto>(body);
+        Assert.Equal(typed, sent.Title);
+    }
+}