public async Task <FileSet> CreateAsync(CancellationToken cancellationToken)
{
var watchList = Path.Combine(Path.GetTempPath(), Path.GetRandomFileName());
try
{
var projectDir = Path.GetDirectoryName(_projectFile);
while (true)
{
cancellationToken.ThrowIfCancellationRequested();
var capture = _outputSink.StartCapture();
var arguments = new List <string>
{
"msbuild",
"/nologo",
_projectFile,
$"/p:_DotNetWatchListFile={watchList}",
};
if (_dotNetWatchOptions.SuppressHandlingStaticContentFiles)
{
arguments.Add("/p:DotNetWatchContentFiles=false");
}
arguments.AddRange(_buildFlags);
var processSpec = new ProcessSpec
{
Executable = _muxerPath,
WorkingDirectory = projectDir,
Arguments = arguments,
OutputCapture = capture
};
_reporter.Verbose($"Running MSBuild target '{TargetName}' on '{_projectFile}'");
var exitCode = await _processRunner.RunAsync(processSpec, cancellationToken);
if (exitCode == 0 && File.Exists(watchList))
{
using var watchFile = File.OpenRead(watchList);
var result = await JsonSerializer.DeserializeAsync <MSBuildFileSetResult>(watchFile, cancellationToken : cancellationToken);
var fileItems = new List <FileItem>();
foreach (var project in result.Projects)
{
var value = project.Value;
var fileCount = value.Files.Count;
for (var i = 0; i < fileCount; i++)
{
fileItems.Add(new FileItem
{
FilePath = value.Files[i],
ProjectPath = project.Key,
});
}
var staticItemsCount = value.StaticFiles.Count;
for (var i = 0; i < staticItemsCount; i++)
{
var item = value.StaticFiles[i];
fileItems.Add(new FileItem
{
FilePath = item.FilePath,
ProjectPath = project.Key,
IsStaticFile = true,
StaticWebAssetPath = item.StaticWebAssetPath,
});
}
}
_reporter.Verbose($"Watching {fileItems.Count} file(s) for changes");
#if DEBUG
foreach (var file in fileItems)
{
_reporter.Verbose($" -> {file.FilePath} {(file.IsStaticFile ? file.StaticWebAssetPath : null)}");
}
Debug.Assert(fileItems.All(f => Path.IsPathRooted(f.FilePath)), "All files should be rooted paths");
#endif
// TargetFrameworkVersion appears as v6.0 in msbuild. Ignore the leading v
var targetFrameworkVersion = !string.IsNullOrEmpty(result.TargetFrameworkVersion) ?
Version.Parse(result.TargetFrameworkVersion.AsSpan(1)) : // Ignore leading v
null;
var projectInfo = new ProjectInfo(
_projectFile,
result.IsNetCoreApp,
targetFrameworkVersion,
result.RunCommand,
result.RunArguments,
result.RunWorkingDirectory);
return(new FileSet(projectInfo, fileItems));
}
_reporter.Error($"Error(s) finding watch items project file '{Path.GetFileName(_projectFile)}'");
_reporter.Output($"MSBuild output from target '{TargetName}':");
_reporter.Output(string.Empty);
foreach (var line in capture.Lines)
{
_reporter.Output($" {line}");
}
_reporter.Output(string.Empty);
if (!_waitOnError)
{
return(null);
}
else
{
_reporter.Warn("Fix the error to continue or press Ctrl+C to exit.");
var fileSet = new FileSet(null, new[] { new FileItem {
FilePath = _projectFile
} });
using (var watcher = new FileSetWatcher(fileSet, _reporter))
{
await watcher.GetChangedFileAsync(cancellationToken);
_reporter.Output($"File changed: {_projectFile}");
}
}
}
}
finally
{
if (File.Exists(watchList))
{
File.Delete(watchList);
}
}
}
public async Task WatchAsync(DotNetWatchContext context, CancellationToken cancellationToken)
{
var processSpec = context.ProcessSpec;
if (context.SuppressMSBuildIncrementalism)
{
_reporter.Verbose("MSBuild incremental optimizations suppressed.");
}
_reporter.Output("Hot reload enabled. For a list of supported edits, see https://aka.ms/dotnet/hot-reload. " +
"Press \"Ctrl + R\" to restart.");
while (true)
{
context.Iteration++;
for (var i = 0; i < _filters.Length; i++)
{
await _filters[i].ProcessAsync(context, cancellationToken);
}
// Reset for next run
context.RequiresMSBuildRevaluation = false;
processSpec.EnvironmentVariables["DOTNET_WATCH_ITERATION"] = (context.Iteration + 1).ToString(CultureInfo.InvariantCulture);
var fileSet = context.FileSet;
if (fileSet == null)
{
_reporter.Error("Failed to find a list of files to watch");
return;
}
if (!fileSet.Project.IsNetCoreApp60OrNewer())
{
_reporter.Error($"Hot reload based watching is only supported in .NET 6.0 or newer apps. Update the project's launchSettings.json to disable this feature.");
return;
}
if (cancellationToken.IsCancellationRequested)
{
return;
}
if (context.Iteration == 0)
{
ConfigureExecutable(context, processSpec);
}
using var currentRunCancellationSource = new CancellationTokenSource();
var forceReload = _console.ListenForForceReloadRequest();
using var combinedCancellationSource = CancellationTokenSource.CreateLinkedTokenSource(
cancellationToken,
currentRunCancellationSource.Token,
forceReload);
using var fileSetWatcher = new FileSetWatcher(fileSet, _reporter);
try
{
using var hotReload = new HotReload(_processRunner, _reporter);
await hotReload.InitializeAsync(context, cancellationToken);
var processTask = _processRunner.RunAsync(processSpec, combinedCancellationSource.Token);
var args = string.Join(" ", processSpec.Arguments);
_reporter.Verbose($"Running {processSpec.ShortDisplayName()} with the following arguments: {args}");
_reporter.Output("Started");
Task <FileItem?> fileSetTask;
Task finishedTask;
while (true)
{
fileSetTask = fileSetWatcher.GetChangedFileAsync(combinedCancellationSource.Token);
finishedTask = await Task.WhenAny(processTask, fileSetTask).WaitAsync(combinedCancellationSource.Token);
if (finishedTask != fileSetTask || fileSetTask.Result is not FileItem fileItem)
{
// The app exited.
break;
}
else
{
_reporter.Output($"File changed: {fileItem.FilePath}.");
var start = Stopwatch.GetTimestamp();
if (await hotReload.TryHandleFileChange(context, fileItem, combinedCancellationSource.Token))
{
var totalTime = TimeSpan.FromTicks(Stopwatch.GetTimestamp() - start);
_reporter.Output($"Hot reload of changes succeeded.");
_reporter.Verbose($"Hot reload applied in {totalTime.TotalMilliseconds}ms.");
}
else
{
_reporter.Verbose($"Unable to handle changes to {fileItem.FilePath}. Rebuilding the app.");
break;
}
}
}
// Regardless of the which task finished first, make sure everything is cancelled
// and wait for dotnet to exit. We don't want orphan processes
currentRunCancellationSource.Cancel();
await Task.WhenAll(processTask, fileSetTask);
if (processTask.Result != 0 && finishedTask == processTask && !cancellationToken.IsCancellationRequested)
{
// Only show this error message if the process exited non-zero due to a normal process exit.
// Don't show this if dotnet-watch killed the inner process due to file change or CTRL+C by the user
_reporter.Error($"Exited with error code {processTask.Result}");
}
else
{
_reporter.Output("Exited");
}
if (finishedTask == processTask)
{
// Process exited. Redo evaludation
context.RequiresMSBuildRevaluation = true;
// Now wait for a file to change before restarting process
context.ChangedFile = await fileSetWatcher.GetChangedFileAsync(cancellationToken, () => _reporter.Warn("Waiting for a file to change before restarting dotnet..."));
}
else
{
Debug.Assert(finishedTask == fileSetTask);
var changedFile = fileSetTask.Result;
context.ChangedFile = changedFile;
}
}
public async Task <IFileSet> CreateAsync(CancellationToken cancellationToken)
{
var watchList = Path.Combine(Path.GetTempPath(), Path.GetRandomFileName());
try
{
var projectDir = Path.GetDirectoryName(_projectFile);
while (true)
{
cancellationToken.ThrowIfCancellationRequested();
var capture = _outputSink.StartCapture();
var processSpec = new ProcessSpec
{
Executable = _muxerPath,
WorkingDirectory = projectDir,
Arguments = new[]
{
"msbuild",
"/nologo",
_projectFile,
$"/p:_DotNetWatchListFile={watchList}",
}.Concat(_buildFlags),
OutputCapture = capture
};
_reporter.Verbose($"Running MSBuild target '{TargetName}' on '{_projectFile}'");
var exitCode = await _processRunner.RunAsync(processSpec, cancellationToken);
if (exitCode == 0 && File.Exists(watchList))
{
var lines = File.ReadAllLines(watchList);
var isNetCoreApp31OrNewer = lines.FirstOrDefault() == "true";
var fileset = new FileSet(
isNetCoreApp31OrNewer,
lines.Skip(1)
.Select(l => l?.Trim())
.Where(l => !string.IsNullOrEmpty(l)));
_reporter.Verbose($"Watching {fileset.Count} file(s) for changes");
#if DEBUG
foreach (var file in fileset)
{
_reporter.Verbose($" -> {file}");
}
Debug.Assert(fileset.All(Path.IsPathRooted), "All files should be rooted paths");
#endif
return(fileset);
}
_reporter.Error($"Error(s) finding watch items project file '{Path.GetFileName(_projectFile)}'");
_reporter.Output($"MSBuild output from target '{TargetName}':");
_reporter.Output(string.Empty);
foreach (var line in capture.Lines)
{
_reporter.Output($" {line}");
}
_reporter.Output(string.Empty);
if (!_waitOnError)
{
return(null);
}
else
{
_reporter.Warn("Fix the error to continue or press Ctrl+C to exit.");
var fileSet = new FileSet(false, new[] { _projectFile });
using (var watcher = new FileSetWatcher(fileSet, _reporter))
{
await watcher.GetChangedFileAsync(cancellationToken);
_reporter.Output($"File changed: {_projectFile}");
}
}
}
}
finally
{
if (File.Exists(watchList))
{
File.Delete(watchList);
}
}
}