From 7c0f8d8408f077f1e3fc2f9d9fe372996dda3191 Mon Sep 17 00:00:00 2001
From: mika kuns <mika.kuns@fb-tuning.de>
Date: Thu, 23 Apr 2026 14:21:25 +0200
Subject: [PATCH] feat(releases): add VersionComparer

---
 src/ClaudeDo.Releases/VersionComparer.cs      | 18 +++++++++++
 .../VersionComparerTests.cs                   | 30 +++++++++++++++++++
 2 files changed, 48 insertions(+)
 create mode 100644 src/ClaudeDo.Releases/VersionComparer.cs
 create mode 100644 tests/ClaudeDo.Releases.Tests/VersionComparerTests.cs

diff --git a/src/ClaudeDo.Releases/VersionComparer.cs b/src/ClaudeDo.Releases/VersionComparer.cs
new file mode 100644
index 0000000..e38d1fc
--- /dev/null
+++ b/src/ClaudeDo.Releases/VersionComparer.cs
@@ -0,0 +1,18 @@
+namespace ClaudeDo.Releases;
+
+public readonly record struct VersionCompareResult(bool IsNewer, bool Unparseable);
+
+public static class VersionComparer
+{
+    public static VersionCompareResult Compare(string latest, string current)
+    {
+        var latestTrimmed = (latest ?? "").TrimStart('v', 'V');
+        var currentTrimmed = (current ?? "").TrimStart('v', 'V');
+
+        var unparseable = !Version.TryParse(latestTrimmed, out var lv)
+                        | !Version.TryParse(currentTrimmed, out var cv);
+
+        if (unparseable) return new VersionCompareResult(false, true);
+        return new VersionCompareResult(lv > cv, false);
+    }
+}
diff --git a/tests/ClaudeDo.Releases.Tests/VersionComparerTests.cs b/tests/ClaudeDo.Releases.Tests/VersionComparerTests.cs
new file mode 100644
index 0000000..5aba89f
--- /dev/null
+++ b/tests/ClaudeDo.Releases.Tests/VersionComparerTests.cs
@@ -0,0 +1,30 @@
+namespace ClaudeDo.Releases.Tests;
+
+public class VersionComparerTests
+{
+    [Theory]
+    [InlineData("0.2.0", "0.1.0", true, false)]
+    [InlineData("0.2.0", "0.2.0", false, false)]
+    [InlineData("0.1.0", "0.2.0", false, false)]
+    [InlineData("v0.2.0", "0.1.0", true, false)]
+    [InlineData("0.2.0", "v0.1.0", true, false)]
+    [InlineData("1.0.0.0", "0.99.99.99", true, false)]
+    public void Compare_ParseableVersions(string latest, string current, bool expectedNewer, bool expectedUnparseable)
+    {
+        var result = VersionComparer.Compare(latest, current);
+        Assert.Equal(expectedNewer, result.IsNewer);
+        Assert.Equal(expectedUnparseable, result.Unparseable);
+    }
+
+    [Theory]
+    [InlineData("0.2.0-beta", "0.1.0")]
+    [InlineData("0.2.0", "0.1.0-alpha")]
+    [InlineData("garbage", "0.1.0")]
+    [InlineData("", "0.1.0")]
+    public void Compare_UnparseableReturnsNotNewer(string latest, string current)
+    {
+        var result = VersionComparer.Compare(latest, current);
+        Assert.False(result.IsNewer);
+        Assert.True(result.Unparseable);
+    }
+}