Add end-to-end tests for stamp-based cache hits

Fix dev mode to pass the entry file directly to dotnet run instead of the publish-only --ucr flag.

Author: kzu

plans/README.md

@@ -10,7 +10,7 @@ executor needs no context beyond the plan file itself.
 | # | Plan | Priority | Effort | Depends on | Status |
 |---|------|----------|--------|------------|--------|
 | 001 | [Harden background cache cleanup](001-harden-cache-cleanup.md) | P1 | S | — | DONE |
-| 002 | [End-to-end cache behavior tests](002-e2e-cache-tests.md) | P1 | M | — | TODO |
+| 002 | [End-to-end cache behavior tests](002-e2e-cache-tests.md) | P1 | M | — | DONE |
 | 003 | [`go clean --all`](003-clean-all.md) | P2 | S | 001 | TODO |
 | 004 | [Readme: cache and cleaning docs](004-readme-cache-docs.md) | P2 | S | 003 | TODO |
 

src/Tests/EndToEndTests.cs

@@ -0,0 +1,164 @@
+using System.Diagnostics;
+using Devlooped;
+
+namespace Tests;
+
+public class EndToEndTests
+{
+    [Fact]
+    public void Dev_second_run_hits_cache_and_edit_invalidates()
+    {
+        var marker = "e2e-" + Guid.NewGuid().ToString("N");
+        var app = CreateApp(marker);
+
+        try
+        {
+            var (exit1, output1) = RunGo("dev", app);
+            Assert.Equal(0, exit1);
+            Assert.Contains(marker, output1);
+
+            var stamp = FindStamp(app);
+            Assert.True(File.Exists(stamp));
+            var stampContent = File.ReadAllText(stamp);
+            var stampWriteTime = File.GetLastWriteTimeUtc(stamp);
+
+            var (exit2, output2) = RunGo("dev", app);
+            Assert.Equal(0, exit2);
+            Assert.Contains(marker, output2);
+            Assert.Equal(stampContent, File.ReadAllText(stamp));
+            Assert.Equal(stampWriteTime, File.GetLastWriteTimeUtc(stamp));
+
+            var marker2 = "e2e-" + Guid.NewGuid().ToString("N");
+            File.WriteAllText(app, $"""
+                #:property TargetFramework=net10.0
+
+                Console.WriteLine("{marker2}");
+                """);
+            File.SetLastWriteTimeUtc(app, DateTime.UtcNow.AddSeconds(2));
+
+            var (exit3, output3) = RunGo("dev", app);
+            Assert.Equal(0, exit3);
+            Assert.Contains(marker2, output3);
+            Assert.DoesNotContain(marker, output3);
+            Assert.NotEqual(stampContent, File.ReadAllText(stamp));
+        }
+        finally
+        {
+            CleanApp(app);
+        }
+    }
+
+    [Fact]
+    public void Publish_r2r_second_run_hits_cache()
+    {
+        var marker = "e2e-" + Guid.NewGuid().ToString("N");
+        var app = CreateApp(marker);
+
+        try
+        {
+            var (exit1, output1) = RunGo(app, "--r2r");
+            Assert.Equal(0, exit1);
+            Assert.Contains(marker, output1);
+
+            var stamp = FindStamp(app);
+            var stampContent = File.ReadAllText(stamp);
+            Assert.Contains("app=", stampContent);
+            Assert.Contains("mode=r2r", stampContent);
+            var stampWriteTime = File.GetLastWriteTimeUtc(stamp);
+
+            var (exit2, output2) = RunGo(app, "--r2r");
+            Assert.Equal(0, exit2);
+            Assert.Contains(marker, output2);
+            Assert.Equal(stampContent, File.ReadAllText(stamp));
+            Assert.Equal(stampWriteTime, File.GetLastWriteTimeUtc(stamp));
+        }
+        finally
+        {
+            CleanApp(app);
+        }
+    }
+
+    static string CreateApp(string marker)
+    {
+        var dir = CreateTempDir();
+        var app = Path.Combine(dir, "app.cs");
+        File.WriteAllText(app, $"""
+            #:property TargetFramework=net10.0
+
+            Console.WriteLine("{marker}");
+            """);
+        return app;
+    }
+
+    static string GetTempRoot()
+    {
+        var directory = OperatingSystem.IsWindows()
+            ? Path.GetTempPath()
+            : Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
+        return Path.Join(directory, "dotnet", "go");
+    }
+
+    static string FindStamp(string appFile)
+    {
+        var normalizedInput = $"input={appFile.Replace('\\', '/')}";
+        var prefix = Path.GetFileNameWithoutExtension(appFile) + "-";
+        var matches = Directory.GetDirectories(GetTempRoot(), prefix + "*")
+            .Where(dir => File.Exists(Path.Combine(dir, "go.stamp")))
+            .Where(dir => File.ReadAllText(Path.Combine(dir, "go.stamp")).Contains(normalizedInput))
+            .ToArray();
+
+        Assert.Single(matches);
+        return Path.Combine(matches[0], "go.stamp");
+    }
+
+    static (int ExitCode, string Output) RunGo(params string[] args)
+    {
+        var startInfo = new ProcessStartInfo
+        {
+            FileName = DotnetMuxer.Path!.FullName,
+            RedirectStandardOutput = true,
+            RedirectStandardError = true,
+            UseShellExecute = false,
+        };
+        startInfo.Environment["NO_COLOR"] = "true";
+        startInfo.ArgumentList.Add(Path.Combine(AppContext.BaseDirectory, "go.dll"));
+        foreach (var arg in args)
+            startInfo.ArgumentList.Add(arg);
+
+        using var process = Process.Start(startInfo)!;
+        var stdout = process.StandardOutput.ReadToEndAsync();
+        var stderr = process.StandardError.ReadToEndAsync();
+        process.WaitForExit();
+        Task.WaitAll(stdout, stderr);
+
+        return (process.ExitCode, stdout.Result + stderr.Result);
+    }
+
+    static void CleanApp(string appFile)
+    {
+        try
+        {
+            RunGo("clean", appFile);
+        }
+        catch
+        {
+        }
+
+        try
+        {
+            var dir = Path.GetDirectoryName(appFile);
+            if (dir is not null && Directory.Exists(dir))
+                Directory.Delete(dir, recursive: true);
+        }
+        catch
+        {
+        }
+    }
+
+    static string CreateTempDir()
+    {
+        var dir = Path.Combine(Path.GetTempPath(), "go-tests-" + Guid.NewGuid().ToString("N"));
+        Directory.CreateDirectory(dir);
+        return dir;
+    }
+}

src/go/ProcessRunner.cs

@@ -20,7 +20,7 @@ public static Task<int> DotnetRunAsync(string dotnet, string cs, string config,
     {
         var environment = CreateGoEnvironment(config, targets);
 
-        var arguments = new List<string> { "run", "--ucr", cs };
+        var arguments = new List<string> { "run", cs };
         if (dotnetArgs is not null)
             arguments.AddRange(dotnetArgs);