Things were working, suddenly regressed

SVSim.UnitTests/Extensions/FormatExtensionsTests.cs

@@ -0,0 +1,95 @@
+using System.Text.Json;
+using SVSim.Database.Enums;
+using SVSim.EmulatedEntrypoint.Extensions;
+
+namespace SVSim.UnitTests.Extensions;
+
+/// <summary>
+/// Pins the wire deck_format mapping against the client's <c>Data.FormatConvertApi</c>
+/// (Shadowverse_Code/Assembly-CSharp/Wizard/Data.cs:580). Each row in <see cref="WireMapping"/>
+/// is "internal Format ↔ wire int" and must match the client decompile exactly — see
+/// docs/api-spec/common/types.ts.md for the table.
+/// </summary>
+public class FormatExtensionsTests
+{
+    /// <summary>(internal Format, wire deck_format int)</summary>
+    public static IEnumerable<(Format Format, int Wire)> WireMapping => new (Format, int)[]
+    {
+        (Format.Rotation,    1),
+        (Format.Unlimited,   2),
+        (Format.PreRotation, 3),
+        (Format.Crossover,   4),
+        (Format.MyRotation,  5),
+        (Format.TwoPick,     10),
+        (Format.Sealed,      20),
+        (Format.Hof,         31),
+        (Format.Windfall,    33),
+        (Format.Avatar,      39),
+        (Format.All,         0),
+    };
+
+    [TestCaseSource(nameof(WireMapping))]
+    public void ToApi_matches_client_FormatConvertApi((Format Format, int Wire) row)
+    {
+        Assert.That(row.Format.ToApi(), Is.EqualTo(row.Wire));
+    }
+
+    [TestCaseSource(nameof(WireMapping))]
+    public void FromApi_inverts_ToApi((Format Format, int Wire) row)
+    {
+        Assert.That(FormatExtensions.FromApi(row.Wire), Is.EqualTo(row.Format));
+    }
+
+    [Test]
+    public void ToApi_Max_aliases_onto_Rotation_per_client_FormatConvertApi()
+    {
+        // Format.Max is a client-side sentinel ("invalid/unknown"); the client's
+        // FormatConvertApi sends it as wire 1 (same slot as Rotation). Pinned so we can spot
+        // the day the client decompile changes this.
+        Assert.That(Format.Max.ToApi(), Is.EqualTo(1));
+    }
+
+    [Test]
+    public void ToApi_throws_on_unmapped_format()
+    {
+        Assert.Throws<ArgumentOutOfRangeException>(() => ((Format)9999).ToApi());
+    }
+
+    [TestCase(7)]
+    [TestCase(99)]
+    [TestCase(-1)]
+    public void FromApi_throws_on_unknown_wire_code(int wire)
+    {
+        Assert.Throws<ArgumentOutOfRangeException>(() => FormatExtensions.FromApi(wire));
+    }
+
+    // ---- JSON converter ----
+
+    private static JsonSerializerOptions ConverterOptions()
+    {
+        var opts = new JsonSerializerOptions();
+        opts.Converters.Add(new FormatJsonConverter());
+        return opts;
+    }
+
+    [TestCaseSource(nameof(WireMapping))]
+    public void JsonConverter_writes_wire_code((Format Format, int Wire) row)
+    {
+        string json = JsonSerializer.Serialize(row.Format, ConverterOptions());
+        Assert.That(json, Is.EqualTo(row.Wire.ToString()));
+    }
+
+    [TestCaseSource(nameof(WireMapping))]
+    public void JsonConverter_reads_wire_code((Format Format, int Wire) row)
+    {
+        Format result = JsonSerializer.Deserialize<Format>(row.Wire.ToString(), ConverterOptions());
+        Assert.That(result, Is.EqualTo(row.Format));
+    }
+
+    [Test]
+    public void JsonConverter_rejects_non_numeric_input()
+    {
+        Assert.Throws<JsonException>(() =>
+            JsonSerializer.Deserialize<Format>("\"rotation\"", ConverterOptions()));
+    }
+}