Better organize dotnet-watch source files and clean up (#49524)

Author: tmat

src/BuiltInTools/DotNetWatchTasks/DotNetWatchTasks.csproj

@@ -10,7 +10,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <Compile Include="..\dotnet-watch\Internal\MSBuildFileSetResult.cs" />
+    <Compile Include="..\dotnet-watch\Build\MSBuildFileSetResult.cs" />
   </ItemGroup>
 
 </Project>

src/BuiltInTools/dotnet-watch/Internal/BrowserSpecificReporter.cs renamed to src/BuiltInTools/dotnet-watch/Browser/BrowserSpecificReporter.cs

@@ -68,7 +68,7 @@ internal class MSBuildFileSetFactory(
                     reporter.Output($"MSBuild output from target '{TargetName}':");
                 }
 
-                BuildUtilities.ReportBuildOutput(reporter, capturedOutput, success, projectDisplay: null);
+                BuildOutput.ReportBuildOutput(reporter, capturedOutput, success, projectDisplay: null);
                 if (!success)
                 {
                     return null;

src/BuiltInTools/dotnet-watch/DotNetWatch.targets renamed to src/BuiltInTools/dotnet-watch/Build/DotNetWatch.targets

@@ -12,5 +12,13 @@ internal sealed class DotNetWatchContext
         public required ProcessRunner ProcessRunner { get; init; }
 
         public required ProjectOptions RootProjectOptions { get; init; }
+
+        public MSBuildFileSetFactory CreateMSBuildFileSetFactory()
+            => new(
+                RootProjectOptions.ProjectPath,
+                RootProjectOptions.BuildArguments,
+                EnvironmentOptions,
+                ProcessRunner,
+                Reporter);
     }
 }

src/BuiltInTools/dotnet-watch/EvaluationResult.cs renamed to src/BuiltInTools/dotnet-watch/Build/EvaluationResult.cs

@@ -25,8 +25,6 @@ private sealed class ProcessState
         /// <param name="isUserApplication">True if the process is a user application, false if it is a helper process (e.g. msbuild).</param>
         public async Task<int> RunAsync(ProcessSpec processSpec, IReporter reporter, bool isUserApplication, ProcessLaunchResult? launchResult, CancellationToken processTerminationToken)
         {
-            Ensure.NotNull(processSpec, nameof(processSpec));
-
             var state = new ProcessState();
             var stopwatch = new Stopwatch();
 

src/BuiltInTools/dotnet-watch/FileItem.cs renamed to src/BuiltInTools/dotnet-watch/Build/FileItem.cs

@@ -1,6 +1,8 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System.Diagnostics.CodeAnalysis;
+using System.Globalization;
 using System.Runtime.Loader;
 using Microsoft.Build.Locator;
 
@@ -76,14 +78,8 @@ public static async Task<int> Main(string[] args)
                 reporter.Verbose($"Test flags: {environmentOptions.TestFlags}");
             }
 
-            string projectPath;
-            try
-            {
-                projectPath = MsBuildProjectFinder.FindMsBuildProject(workingDirectory, options.ProjectPath);
-            }
-            catch (FileNotFoundException ex)
+            if (!TryFindProject(workingDirectory, options, reporter, out var projectPath))
             {
-                reporter.Error(ex.Message);
                 errorCode = 1;
                 return null;
             }
@@ -93,6 +89,51 @@ public static async Task<int> Main(string[] args)
             return new Program(console, reporter, rootProjectOptions, options, environmentOptions);
         }
 
+        /// <summary>
+        /// Finds a compatible MSBuild project.
+        /// <param name="searchBase">The base directory to search</param>
+        /// <param name="project">The filename of the project. Can be null.</param>
+        /// </summary>
+        private static bool TryFindProject(string searchBase, CommandLineOptions options, IReporter reporter, [NotNullWhen(true)] out string? projectPath)
+        {
+            projectPath = options.ProjectPath ?? searchBase;
+
+            if (!Path.IsPathRooted(projectPath))
+            {
+                projectPath = Path.Combine(searchBase, projectPath);
+            }
+
+            if (Directory.Exists(projectPath))
+            {
+                var projects = Directory.EnumerateFileSystemEntries(projectPath, "*.*proj", SearchOption.TopDirectoryOnly)
+                    .Where(f => !".xproj".Equals(Path.GetExtension(f), StringComparison.OrdinalIgnoreCase))
+                    .ToList();
+
+                if (projects.Count > 1)
+                {
+                    reporter.Error(string.Format(CultureInfo.CurrentCulture, Resources.Error_MultipleProjectsFound, projectPath));
+                    return false;
+                }
+
+                if (projects.Count == 0)
+                {
+                    reporter.Error(string.Format(CultureInfo.CurrentCulture, Resources.Error_NoProjectsFound, projectPath));
+                    return false;
+                }
+
+                projectPath = projects[0];
+                return true;
+            }
+
+            if (!File.Exists(projectPath))
+            {
+                reporter.Error(string.Format(CultureInfo.CurrentCulture, Resources.Error_ProjectPath_NotFound, projectPath));
+                    return false;
+            }
+
+            return true;
+        }
+
         // internal for testing
         internal async Task<int> RunAsync()
         {
@@ -132,8 +173,23 @@ internal async Task<int> RunAsync()
                     return await ListFilesAsync(processRunner, shutdownCancellationToken);
                 }
 
-                var watcher = CreateWatcher(processRunner, runtimeProcessLauncherFactory: null);
-                await watcher.WatchAsync(shutdownCancellationToken);
+                if (environmentOptions.IsPollingEnabled)
+                {
+                    reporter.Output("Polling file watcher is enabled");
+                }
+
+                var context = CreateContext(processRunner);
+
+                if (IsHotReloadEnabled())
+                {
+                    var watcher = new HotReloadDotNetWatcher(context, console, runtimeProcessLauncherFactory: null);
+                    await watcher.WatchAsync(shutdownCancellationToken);
+                }
+                else
+                {
+                    await DotNetWatcher.WatchAsync(context, shutdownCancellationToken);
+                }
+
                 return 0;
             }
             catch (OperationCanceledException) when (shutdownCancellationToken.IsCancellationRequested)
@@ -155,49 +211,32 @@ internal async Task<int> RunAsync()
         }
 
         // internal for testing
-        internal Watcher CreateWatcher(ProcessRunner processRunner, IRuntimeProcessLauncherFactory? runtimeProcessLauncherFactory)
-        {
-            if (environmentOptions.IsPollingEnabled)
+        internal DotNetWatchContext CreateContext(ProcessRunner processRunner)
+            => new()
             {
-                reporter.Output("Polling file watcher is enabled");
-            }
-
-            var fileSetFactory = new MSBuildFileSetFactory(
-                rootProjectOptions.ProjectPath,
-                rootProjectOptions.BuildArguments,
-                environmentOptions,
-                processRunner,
-                reporter);
+                Reporter = reporter,
+                ProcessRunner = processRunner,
+                Options = options.GlobalOptions,
+                EnvironmentOptions = environmentOptions,
+                RootProjectOptions = rootProjectOptions,
+            };
 
-            bool enableHotReload;
+        private bool IsHotReloadEnabled()
+        {
             if (rootProjectOptions.Command != "run")
             {
                 reporter.Verbose($"Command '{rootProjectOptions.Command}' does not support Hot Reload.");
-                enableHotReload = false;
+                return false;
             }
-            else if (options.GlobalOptions.NoHotReload)
+
+            if (options.GlobalOptions.NoHotReload)
             {
                 reporter.Verbose("Hot Reload disabled by command line switch.");
-                enableHotReload = false;
+                return false;
             }
-            else
-            {
-                reporter.Report(MessageDescriptor.WatchingWithHotReload);
-                enableHotReload = true;
-            }
-
-            var context = new DotNetWatchContext
-            {
-                Reporter = reporter,
-                ProcessRunner = processRunner,
-                Options = options.GlobalOptions,
-                EnvironmentOptions = environmentOptions,
-                RootProjectOptions = rootProjectOptions,
-            };
 
-            return enableHotReload
-                ? new HotReloadDotNetWatcher(context, console, fileSetFactory, runtimeProcessLauncherFactory)
-                : new DotNetWatcher(context, fileSetFactory);
+            reporter.Report(MessageDescriptor.WatchingWithHotReload);
+            return true;
         }
 
         private async Task<int> ListFilesAsync(ProcessRunner processRunner, CancellationToken cancellationToken)

src/BuiltInTools/dotnet-watch/HotReload/FilePathExclusions.cs renamed to src/BuiltInTools/dotnet-watch/Build/FilePathExclusions.cs

@@ -5,7 +5,7 @@
 
 namespace Microsoft.DotNet.Watch;
 
-internal static partial class BuildUtilities
+internal static partial class BuildOutput
 {
     private const string BuildEmoji = "🔨";
     private static readonly Regex s_buildDiagnosticRegex = GetBuildDiagnosticRegex();