feat: support CNBETAWin4.5.53

tests/CapySR.Tests/HotfixTests.cs

@@ -0,0 +1,78 @@
+using CapySR.Common;
+using Xunit;
+
+namespace CapySR.Tests;
+
+// A beta dispatch stops answering once its window closes, so a client that updated past
+// everything in config/versions.json has to be served from the closest build on hand.
+public class GameVersionTests
+{
+    private static readonly string[] Cached =
+    [
+        "OSBETAWin4.4.51",
+        "CNBETAWin4.4.53",
+        "CNBETAWin4.5.51",
+        "CNBETAWin4.5.52",
+    ];
+
+    [Fact]
+    public void VersionsParseIntoAChannelAndNumbers()
+    {
+        Assert.True(GameVersion.TryParse("CNBETAWin4.5.53", out var version));
+        Assert.Equal("CNBETAWin", version.Channel);
+        Assert.Equal([4, 5, 53], version.Parts);
+
+        Assert.False(GameVersion.TryParse("nonsense", out _));
+        Assert.False(GameVersion.TryParse("CNBETAWin4.5.x", out _));
+        Assert.False(GameVersion.TryParse("", out _));
+        Assert.False(GameVersion.TryParse(null, out _));
+    }
+
+    [Theory]
+    [InlineData("CNBETAWin4.5.52", "CNBETAWin4.5.53", -1)]
+    [InlineData("CNBETAWin4.5.53", "CNBETAWin4.5.52", 1)]
+    [InlineData("CNBETAWin4.5.53", "CNBETAWin4.5.53", 0)]
+    [InlineData("CNBETAWin4.9.0", "CNBETAWin4.10.0", -1)]
+    // a missing trailing part counts as zero, so 4.5 and 4.5.0 are the same build
+    [InlineData("CNBETAWin4.5", "CNBETAWin4.5.0", 0)]
+    public void VersionsCompareNumerically(string left, string right, int expected)
+    {
+        Assert.True(GameVersion.TryParse(left, out var a));
+        Assert.True(GameVersion.TryParse(right, out var b));
+        Assert.Equal(expected, Math.Sign(a.CompareTo(b)));
+    }
+
+    // the case that matters: the client updated past anything the dispatch will still serve
+    [Fact]
+    public void ANewerClientBorrowsTheClosestOlderBuild()
+    {
+        Assert.True(GameVersion.TryFindNearest(Cached, "CNBETAWin4.5.53", out var nearest));
+        Assert.Equal("CNBETAWin4.5.52", nearest);
+    }
+
+    [Fact]
+    public void ChannelsNeverBorrowFromEachOther()
+    {
+        Assert.True(GameVersion.TryFindNearest(Cached, "OSBETAWin4.9.99", out var os));
+        Assert.Equal("OSBETAWin4.4.51", os);
+
+        Assert.False(GameVersion.TryFindNearest(Cached, "CNPRODWin4.5.53", out _));
+        Assert.False(GameVersion.TryFindNearest(Cached, "nonsense", out _));
+        Assert.False(GameVersion.TryFindNearest([], "CNBETAWin4.5.53", out _));
+    }
+
+    // nothing older to fall back on, so the newest known build beats having no urls at all
+    [Fact]
+    public void AnOlderClientStillGetsUrls()
+    {
+        Assert.True(GameVersion.TryFindNearest(Cached, "CNBETAWin3.0.0", out var nearest));
+        Assert.Equal("CNBETAWin4.5.52", nearest);
+    }
+
+    [Fact]
+    public void AnExactMatchIsPreferredOverEverythingElse()
+    {
+        Assert.True(GameVersion.TryFindNearest(Cached, "CNBETAWin4.5.51", out var nearest));
+        Assert.Equal("CNBETAWin4.5.51", nearest);
+    }
+}