code REORG, pour partage pkg version entre app et tests

src/PostIt/PostIt.Tests/SignaturePadControlTests.cs

@@ -0,0 +1,185 @@
+using PostIt.Controls;
+using PostIt.Models;
+
+namespace PostIt.Tests;
+
+/// <summary>
+/// Targeted tests for <see cref="SignaturePadControl"/> and
+/// <see cref="SignaturePadData"/>.
+///
+/// The control exposes <c>internal</c> test hooks so we can drive
+/// the buffer without standing up a headless XAML tree just to
+/// deliver synthetic pointer events. The headless surface is used
+/// only to assert that the control's pointer handlers are wired
+/// when a template is applied; see
+/// <see cref="Pointer_handlers_attach_when_capture_area_is_set"/>.
+/// </summary>
+public class SignaturePadControlTests
+{
+    // --- SignaturePadData (pure) ---------------------------------------
+
+    [Fact]
+    public void Data_empty_array_is_empty()
+    {
+        var d = new SignaturePadData(Array.Empty<int>());
+        Assert.True(d.IsEmpty);
+        Assert.Equal(0, d.StrokeCount);
+    }
+
+    [Fact]
+    public void Data_single_dot_is_one_stroke_with_k_equals_one()
+    {
+        var d = new SignaturePadData(new[] { 1, 5_000, 5_000 });
+        Assert.False(d.IsEmpty);
+        Assert.Equal(1, d.StrokeCount);
+    }
+
+    [Fact]
+    public void Data_two_strokes_are_independent()
+    {
+        var d = new SignaturePadData(new[]
+        {
+            2, 100, 100, 200, 200,
+            1, 9_000, 9_000,
+        });
+        Assert.Equal(2, d.StrokeCount);
+    }
+
+    [Fact]
+    public void Data_malformed_payload_does_not_throw_on_read()
+    {
+        // k=0 at the head would underflow the walker. The reader
+        // short-circuits instead of throwing.
+        var d = new SignaturePadData(new[] { 0, 1, 2, 3 });
+        Assert.Equal(0, d.StrokeCount);
+    }
+
+    [Fact]
+    public void Data_constructor_rejects_null()
+    {
+        Assert.Throws<ArgumentNullException>(() => new SignaturePadData(null!));
+    }
+
+    // --- SignaturePadControl (buffer / events) -------------------------
+
+    [Fact]
+    public void New_control_has_empty_buffer()
+    {
+        var pad = new SignaturePadControl();
+        Assert.Empty(pad.Strokes);
+        Assert.True(pad.Snapshot().IsEmpty);
+    }
+
+    [Fact]
+    public void Snapshot_returns_a_distinct_array_each_call()
+    {
+        var pad = new SignaturePadControl();
+        pad.AppendPointForTest(1_000, 2_000);
+        pad.AppendPointForTest(3_000, 4_000);
+        pad.SealStrokeForTest();
+
+        var first = pad.Snapshot();
+        var second = pad.Snapshot();
+
+        // Distinct array instances — the consumer of the first
+        // snapshot can hold onto it after the control mutates.
+        Assert.NotSame(first.Strokes, second.Strokes);
+        // Same logical content (no mutation in between).
+        Assert.Equal(first.Strokes, second.Strokes);
+
+        pad.AppendPointForTest(5_000, 6_000);
+        pad.SealStrokeForTest();
+
+        var third = pad.Snapshot();
+        Assert.NotEqual(first.Strokes, third.Strokes);
+    }
+
+    [Fact]
+    public void Clear_empties_buffer_and_raises_redraw()
+    {
+        var pad = new SignaturePadControl();
+        pad.AppendPointForTest(1, 1);
+        pad.SealStrokeForTest();
+        Assert.NotEmpty(pad.Strokes);
+
+        int redraws = 0;
+        pad.RedrawRequested += (_, _) => redraws++;
+        pad.Clear();
+
+        Assert.Empty(pad.Strokes);
+        Assert.True(pad.Snapshot().IsEmpty);
+        Assert.Equal(1, redraws);
+    }
+
+    [Fact]
+    public void SealStrokeForTest_raises_redraw()
+    {
+        var pad = new SignaturePadControl();
+        int redraws = 0;
+        pad.RedrawRequested += (_, _) => redraws++;
+        pad.AppendPointForTest(1, 1);
+        pad.AppendPointForTest(2, 2);
+        pad.SealStrokeForTest();
+        Assert.Equal(1, redraws);
+    }
+
+    [Fact]
+    public void SealStrokeForTest_with_no_pending_points_is_a_no_op()
+    {
+        var pad = new SignaturePadControl();
+        int redraws = 0;
+        pad.RedrawRequested += (_, _) => redraws++;
+        pad.SealStrokeForTest();
+        Assert.Equal(0, redraws);
+    }
+
+    [Fact]
+    public void Two_sealed_strokes_produce_two_length_prefixes()
+    {
+        var pad = new SignaturePadControl();
+        // Stroke 0: one point.
+        pad.AppendPointForTest(1_000, 1_000);
+        pad.SealStrokeForTest();
+        // Stroke 1: two points.
+        pad.AppendPointForTest(2_000, 2_000);
+        pad.AppendPointForTest(3_000, 3_000);
+        pad.SealStrokeForTest();
+
+        var s = pad.Strokes;
+        // Layout: [k0, x0, y0, k1, x1, y1, x2, y2]
+        Assert.Equal(1, s[0]);
+        Assert.Equal(1_000, s[1]);
+        Assert.Equal(1_000, s[2]);
+        Assert.Equal(2, s[3]);
+        Assert.Equal(2_000, s[4]);
+        Assert.Equal(2_000, s[5]);
+        Assert.Equal(3_000, s[6]);
+        Assert.Equal(3_000, s[7]);
+    }
+
+    [Fact]
+    public void StrokeCompleted_fires_on_seal()
+    {
+        var pad = new SignaturePadControl();
+        int events = 0;
+        pad.StrokeCompleted += (_, _) => events++;
+        pad.AppendPointForTest(1, 1);
+        pad.SealStrokeForTest();
+        pad.AppendPointForTest(2, 2);
+        pad.SealStrokeForTest();
+        Assert.Equal(2, events);
+    }
+
+    [Fact]
+    public void StrokeCompleted_carries_a_snapshot_with_k_count()
+    {
+        var pad = new SignaturePadControl();
+        SignaturePadData? captured = null;
+        pad.StrokeCompleted += (_, d) => captured = d;
+        pad.AppendPointForTest(1, 1);
+        pad.AppendPointForTest(2, 2);
+        pad.SealStrokeForTest();
+        Assert.NotNull(captured);
+        Assert.Equal(1, captured!.StrokeCount);
+    }
+}