Always use the latest version of the alternate package (#547)

Author: SimonCropp

src/Directory.Build.props

@@ -1,7 +1,7 @@
 
 <Project>
   <PropertyGroup>
-    <Version>4.1.5</Version>
+    <Version>4.1.6</Version>
     <LangVersion>preview</LangVersion>
     <NoWarn>NU1608</NoWarn>
     <AssemblyVersion>1.0.0</AssemblyVersion>

src/PackageUpdate/Updater.cs

@@ -314,12 +314,8 @@ public static async Task Update(
         // Perform migration: update Include attribute and Version
         packageElement.SetAttributeValue("Include", alternatePackage.PackageId);
 
-        // Use the minimum version from the range if specified and greater than 0.0.0,
-        // otherwise use the latest version we found
-        var minVersion = alternatePackage.Range?.MinVersion;
-        var targetVersion = minVersion != null && minVersion > new NuGetVersion(0, 0, 0)
-            ? minVersion
-            : alternateMetadata.Identity.Version;
+        // Always use the latest version of the alternate package
+        var targetVersion = alternateMetadata.Identity.Version;
         packageElement.SetAttributeValue("Version", targetVersion.ToString());
 
         Log.Information(

src/Tests/UpdaterTests.cs

@@ -1256,6 +1256,47 @@ public async Task NoMigrationDoesNotUpdateCsprojFiles()
         await Assert.That(csprojResult).IsEqualTo(originalCsproj);
     }
 
+    [Test]
+    public async Task MigrationUsesLatestVersionNotMinVersion()
+    {
+        using var cache = new SourceCacheContext { RefreshMemoryCache = true };
+        var content =
+            """
+            <Project>
+              <ItemGroup>
+                <PackageVersion Include="WindowsAzure.Storage" Version="9.3.3" />
+              </ItemGroup>
+            </Project>
+            """;
+
+        using var tempFile = await TempFile.CreateText(content);
+
+        await Updater.Update(cache, tempFile.Path, null);
+
+        var result = await File.ReadAllTextAsync(tempFile.Path);
+        var doc = XDocument.Parse(result);
+
+        var package = doc.Descendants("PackageVersion").Single();
+        var id = package.Attribute("Include")?.Value;
+        var version = package.Attribute("Version")?.Value;
+
+        // Should be migrated to the alternative package
+        await Assert.That(id).IsNotEqualTo("WindowsAzure.Storage");
+
+        // The migrated version should be the latest version of the alternate package,
+        // not the min version from the deprecation range
+        await Assert.That(NuGetVersion.TryParse(version, out var migratedVersion)).IsTrue();
+
+        var latestMetadata = await Updater.GetLatestVersion(
+            id!,
+            new NuGetVersion(0, 0, 0),
+            sources,
+            cache);
+
+        await Assert.That(latestMetadata).IsNotNull();
+        await Assert.That(migratedVersion!).IsEqualTo(latestMetadata!.Identity.Version);
+    }
+
     [Test]
     public async Task ConcurrentRepositoryReaderAccessDoesNotThrow()
     {