Skip MSBuild on run-aspire.cmd when binaries are still newer than sources.

dotnet run always evaluates the Aspire graph. A second launch after Ctrl+C should not wait on that.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/HSchool.AppHost.Tests/LaunchBuildStamp.cs

@@ -0,0 +1,105 @@
+namespace HSchool.AppHost.Tests;
+
+/// <summary>
+/// Same rules as <c>tools/apphost-uptodate.ps1</c>. Keep the two in sync.
+/// </summary>
+internal static class LaunchBuildStamp
+{
+    public const string TargetFramework = "net10.0";
+
+    public static readonly string[] InputExtensions = [".cs", ".csproj", ".props"];
+
+    public static readonly string[] NamedInputs =
+    [
+        "global.json",
+        "Directory.Build.props",
+        "Directory.Packages.props",
+    ];
+
+    public static readonly string[] SkipDirectoryNames = ["bin", "obj", "node_modules"];
+
+    public static readonly string[] OutputProjects = ["HSchool.AppHost", "HSchool.Server"];
+
+    public static bool NeedsBuild(string repoRoot, string configuration = "Debug")
+    {
+        ArgumentException.ThrowIfNullOrWhiteSpace(repoRoot);
+        ArgumentException.ThrowIfNullOrWhiteSpace(configuration);
+
+        DateTime? oldestOutput = null;
+        foreach (var project in OutputProjects)
+        {
+            var dll = Path.Combine(
+                repoRoot,
+                "src",
+                project,
+                "bin",
+                configuration,
+                TargetFramework,
+                project + ".dll");
+            if (!File.Exists(dll))
+            {
+                return true;
+            }
+
+            var written = File.GetLastWriteTimeUtc(dll);
+            if (oldestOutput is null || written < oldestOutput.Value)
+            {
+                oldestOutput = written;
+            }
+        }
+
+        if (oldestOutput is null)
+        {
+            return true;
+        }
+
+        var cutoff = oldestOutput.Value;
+
+        foreach (var name in NamedInputs)
+        {
+            var path = Path.Combine(repoRoot, name);
+            if (File.Exists(path) && File.GetLastWriteTimeUtc(path) > cutoff)
+            {
+                return true;
+            }
+        }
+
+        var src = Path.Combine(repoRoot, "src");
+        return !Directory.Exists(src) || HasNewerInput(src, cutoff);
+    }
+
+    private static bool HasNewerInput(string directory, DateTime cutoff)
+    {
+        foreach (var file in Directory.EnumerateFiles(directory))
+        {
+            if (!IsInputExtension(Path.GetExtension(file)))
+            {
+                continue;
+            }
+
+            if (File.GetLastWriteTimeUtc(file) > cutoff)
+            {
+                return true;
+            }
+        }
+
+        foreach (var child in Directory.EnumerateDirectories(directory))
+        {
+            var leaf = Path.GetFileName(child);
+            if (SkipDirectoryNames.Contains(leaf, StringComparer.OrdinalIgnoreCase))
+            {
+                continue;
+            }
+
+            if (HasNewerInput(child, cutoff))
+            {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    private static bool IsInputExtension(string extension) =>
+        InputExtensions.Contains(extension, StringComparer.OrdinalIgnoreCase);
+}