Add support for static files to dotnet-watch

sdk.sln

@@ -272,6 +272,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "dotnet-watch.Tests", "src\T
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Microsoft.AspNetCore.Watch.BrowserRefresh.Tests", "src\Tests\Microsoft.AspNetCore.Watch.BrowserRefresh.Tests\Microsoft.AspNetCore.Watch.BrowserRefresh.Tests.csproj", "{81ADA3FA-AC26-4149-8CFC-EC7808ECB820}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "DotNetWatchTasks", "src\BuiltInTools\DotNetWatchTasks\DotNetWatchTasks.csproj", "{A41DF752-6F21-4036-AD02-DD37B11A2723}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -498,6 +500,10 @@ Global
 		{81ADA3FA-AC26-4149-8CFC-EC7808ECB820}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{81ADA3FA-AC26-4149-8CFC-EC7808ECB820}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{81ADA3FA-AC26-4149-8CFC-EC7808ECB820}.Release|Any CPU.Build.0 = Release|Any CPU
+		{A41DF752-6F21-4036-AD02-DD37B11A2723}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{A41DF752-6F21-4036-AD02-DD37B11A2723}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{A41DF752-6F21-4036-AD02-DD37B11A2723}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{A41DF752-6F21-4036-AD02-DD37B11A2723}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -590,6 +596,7 @@ Global
 		{A82EF2B9-24BC-4569-8FE5-9EF51017F4CB} = {71A9F549-0EB6-41F9-BC16-4A6C5007FC91}
 		{CCE1A328-9CFE-44D3-B68F-FE84A039ACEA} = {580D1AE7-AA8F-4912-8B76-105594E00B3B}
 		{81ADA3FA-AC26-4149-8CFC-EC7808ECB820} = {580D1AE7-AA8F-4912-8B76-105594E00B3B}
+		{A41DF752-6F21-4036-AD02-DD37B11A2723} = {71A9F549-0EB6-41F9-BC16-4A6C5007FC91}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {FB8F26CE-4DE6-433F-B32A-79183020BBD6}

src/BuiltInTools/BrowserRefresh/WebSocketScriptInjection.js

@@ -7,17 +7,84 @@ setTimeout(function () {
     console.debug(ex);
     return;
   }
+
+  let waiting = false;
+
   connection.onmessage = function (message) {
     if (message.data === 'Reload') {
       console.debug('Server is ready. Reloading...');
       location.reload();
     } else if (message.data === 'Wait') {
+      if (waiting) {
+        return;
+      }
+      waiting = true;
       console.debug('File changes detected. Waiting for application to rebuild.');
-      const t = document.title; const r = ['☱', '☲', '☴']; let i = 0;
-      setInterval(function () { document.title = r[i++ % r.length] + ' ' + t; }, 240);
+      const glyphs = ['☱', '☲', '☴'];
+      const title = document.title;
+      let i = 0;
+      setInterval(function () { document.title = glyphs[i++ % glyphs.length] + ' ' + title; }, 240);
+    } else {
+      const parsed = JSON.parse(message.data);
+      if (parsed.type == 'UpdateStaticFile') {
+        const path = parsed.path;
+        if (path && path.endsWith('.css')) {
+          updateCssByPath(path);
+        } else {
+          console.debug(`File change detected to css file ${path}. Reloading page...`);
+          location.reload();
+          return;
+        }
+      }
     }
   }
+
   connection.onerror = function (event) { console.debug('dotnet-watch reload socket error.', event) }
   connection.onclose = function () { console.debug('dotnet-watch reload socket closed.') }
   connection.onopen = function () { console.debug('dotnet-watch reload socket connected.') }
+
+  function updateCssByPath(path) {
+    const styleElement = document.querySelector(`link[href^="${path}"]`) ||
+      document.querySelector(`link[href^="${document.baseURI}${path}"]`);
+
+    if (!styleElement || !styleElement.parentNode) {
+      console.debug('Unable to find a stylesheet to update. Updating all css.');
+      updateAllLocalCss();
+    }
+
+    updateCssElement(styleElement);
+  }
+
+  function updateAllLocalCss() {
+    [...document.querySelectorAll('link')]
+      .filter(l => l.baseURI === document.baseURI)
+      .forEach(e => updateCssElement(e));
+  }
+
+  function updateCssElement(styleElement) {
+    if (styleElement.loading) {
+      // A file change notification may be triggered for the same file before the browser
+      // finishes processing a previous update. In this case, it's easiest to ignore later updates
+      return;
+    }
+
+    const newElement = styleElement.cloneNode();
+    const href = styleElement.href;
+    newElement.href = href.split('?', 1)[0] + `?nonce=${Date.now()}`;
+
+    styleElement.loading = true;
+    newElement.loading = true;
+    newElement.addEventListener('load', function () {
+      newElement.loading = false;
+      styleElement.remove();
+    });
+
+    styleElement.parentNode.insertBefore(newElement, styleElement.nextSibling);
+  }
+
+  function updateScopedCss() {
+    [...document.querySelectorAll('link')]
+      .filter(l => l.baseURI === document.baseURI && l.href && l.href.indexOf('.styles.css') !== -1)
+      .forEach(e => updateCssElement(e));
+  }
 }, 500);

src/BuiltInTools/DotNetWatchTasks/DotNetWatchTasks.csproj

@@ -0,0 +1,16 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>netstandard2.0</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Build.Framework" Version="$(MicrosoftBuildFrameworkVersion)" ExcludeAssets="Runtime" />
+    <PackageReference Include="Microsoft.Build.Utilities.Core" Version="$(MicrosoftBuildUtilitiesCoreVersion)" ExcludeAssets="Runtime" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Compile Include="..\dotnet-watch\Internal\MSBuildFileSetResult.cs" />
+  </ItemGroup>
+
+</Project>

src/BuiltInTools/DotNetWatchTasks/FileSetSerializer.cs

@@ -0,0 +1,71 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Runtime.Serialization.Json;
+using System.Text;
+using Microsoft.Build.Framework;
+using Microsoft.Build.Utilities;
+using Microsoft.DotNet.Watcher.Internal;
+
+namespace DotNetWatchTasks
+{
+    public class FileSetSerializer : Task
+    {
+        public ITaskItem[] WatchFiles { get; set; }
+
+        public bool IsNetCoreApp31OrNewer { get; set; }
+
+        public ITaskItem OutputPath { get; set; }
+
+        public string[] PackageIds { get; set; }
+
+        public override bool Execute()
+        {
+            var projectItems = new Dictionary<string, ProjectItems>(StringComparer.OrdinalIgnoreCase);
+            var fileSetResult = new MSBuildFileSetResult
+            {
+                IsNetCoreApp31OrNewer = IsNetCoreApp31OrNewer,
+                Projects = projectItems
+            };
+
+            foreach (var item in WatchFiles)
+            {
+                var fullPath = item.GetMetadata("FullPath");
+                var staticWebAssetPath = item.GetMetadata("StaticWebAssetPath");
+                var projectFullPath = item.GetMetadata("ProjectFullPath");
+
+                if (!projectItems.TryGetValue(projectFullPath, out var project))
+                {
+                    projectItems[projectFullPath] = project = new ProjectItems();
+                }
+
+                if (string.IsNullOrEmpty(staticWebAssetPath))
+                {
+                    project.Files.Add(fullPath);
+                }
+                else
+                {
+                    project.StaticFiles.Add(new StaticFileItem
+                    {
+                        FilePath = fullPath,
+                        StaticWebAssetPath = staticWebAssetPath,
+                    });
+                }
+            }
+
+            var serializer = new DataContractJsonSerializer(fileSetResult.GetType(), new DataContractJsonSerializerSettings
+            {
+                UseSimpleDictionaryFormat = true,
+            });
+
+            using var fileStream = File.Create(OutputPath.ItemSpec);
+            using var writer = JsonReaderWriterFactory.CreateJsonWriter(fileStream, Encoding.UTF8, ownsStream: false, indent: true);
+            serializer.WriteObject(writer, fileSetResult);
+
+            return !Log.HasLoggedErrors;
+        }
+    }
+}

src/BuiltInTools/dotnet-watch/BrowserRefreshServer.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Linq;
 using System.Net.WebSockets;
+using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Builder;
@@ -20,6 +21,8 @@ namespace Microsoft.DotNet.Watcher.Tools
 {
     public class BrowserRefreshServer : IAsyncDisposable
     {
+        private readonly byte[] ReloadMessage = Encoding.UTF8.GetBytes("Reload");
+        private readonly byte[] WaitMessage = Encoding.UTF8.GetBytes("Wait");
         private readonly IReporter _reporter;
         private readonly TaskCompletionSource _taskCompletionSource;
         private IHost _refreshServer;
@@ -73,7 +76,7 @@ private async Task WebSocketRequest(HttpContext context)
             await _taskCompletionSource.Task;
         }
 
-        public async Task SendMessage(byte[] messageBytes, CancellationToken cancellationToken = default)
+        public async ValueTask SendMessage(ReadOnlyMemory<byte> messageBytes, CancellationToken cancellationToken = default)
         {
             if (_webSocket == null || _webSocket.CloseStatus.HasValue)
             {
@@ -105,5 +108,9 @@ public async ValueTask DisposeAsync()
 
             _taskCompletionSource.TrySetResult();
         }
+
+        public ValueTask ReloadAsync(CancellationToken cancellationToken) => SendMessage(ReloadMessage, cancellationToken);
+
+        public ValueTask SendWaitMessageAsync(CancellationToken cancellationToken) => SendMessage(WaitMessage, cancellationToken);
     }
 }

src/BuiltInTools/dotnet-watch/DotNetWatch.targets

@@ -7,6 +7,8 @@ Main target called by dotnet-watch. It gathers MSBuild items and writes
 them to a file.
 =========================================================================
 -->
+  <UsingTask AssemblyFile="$(MSBuildThisFileDirectory)DotNetWatchTasks.dll" TaskName="FileSetSerializer" />
+
   <Target Name="GenerateWatchList"
           DependsOnTargets="_CollectWatchItems">
 
@@ -17,14 +19,10 @@ them to a file.
       <_IsMicrosoftNETCoreApp31OrNewer Condition="'$(_IsMicrosoftNETCoreApp31OrNewer)' == ''">false</_IsMicrosoftNETCoreApp31OrNewer>
     </PropertyGroup>
 
-    <ItemGroup>
-      <_WatchListLine Include="$(_IsMicrosoftNETCoreApp31OrNewer)" />
-      <_WatchListLine Include="%(Watch.FullPath)" />
-    </ItemGroup>
-
-    <WriteLinesToFile Overwrite="true"
-                      File="$(_DotNetWatchListFile)"
-                      Lines="@(_WatchListLine)" />
+    <FileSetSerializer
+       IsNetCoreApp31OrNewer="$(_IsMicrosoftNETCoreApp31OrNewer)"
+       OutputPath="$(_DotNetWatchListFile)"
+       WatchFiles="@(Watch)" />
   </Target>
 
 <!--
@@ -45,7 +43,11 @@ Returns: @(Watch)
     </_CollectWatchItemsDependsOn>
   </PropertyGroup>
 
-  <Target Name="_CollectWatchItems" DependsOnTargets="$(_CollectWatchItemsDependsOn)" Returns="@(Watch)" />
+  <Target Name="_CollectWatchItems" DependsOnTargets="$(_CollectWatchItemsDependsOn)" Returns="@(Watch)">
+    <ItemGroup>
+      <Watch ProjectFullPath="$(MSBuildProjectFullPath)" Condition="'%(Watch.ProjectFullPath)' == ''" />
+    </ItemGroup>
+  </Target>
 
   <Target Name="_CollectWatchItemsPerFramework">
     <ItemGroup>
@@ -65,10 +67,21 @@ Returns: @(Watch)
 
     <Error Text="TargetFramework should be set" Condition="'$(TargetFramework)' == '' "/>
 
+    <PropertyGroup Condition="'$(_DotNetWatchUseStaticWebAssetBasePath)' == 'true'">
+      <_DotNetWatchStaticWebAssetBasePath Condition="'$(StaticWebAssetBasePath)' != ''">$(StaticWebAssetBasePath)/</_DotNetWatchStaticWebAssetBasePath>
+      <_DotNetWatchStaticWebAssetBasePath Condition="'$(StaticWebAssetBasePath)' == ''">_content/$(PackageId)/</_DotNetWatchStaticWebAssetBasePath>
+    </PropertyGroup>
+
     <ItemGroup>
       <Watch Include="%(Compile.FullPath)" Condition="'%(Compile.Watch)' != 'false'" />
       <Watch Include="%(EmbeddedResource.FullPath)" Condition="'%(EmbeddedResource.Watch)' != 'false'"/>
       <Watch Include="$(MSBuildProjectFullPath)" />
+
+      <!-- In RazorSDK (Blazor, RCL, and Web) targeting apps also watch content files under wwwroot -->
+      <Watch Include="%(Content.FullPath)"
+             Condition="'$(UsingMicrosoftNETSdkRazor)'=='true' AND '$(DotNetWatchContentFiles)'!='false' AND '%(Content.Watch)' != 'false' AND $([System.String]::Copy('%(Identity)').Replace('\','/').StartsWith('wwwroot/'))"
+             StaticWebAssetPath="$(_DotNetWatchStaticWebAssetBasePath)$([System.String]::Copy('%(Identity)').Replace('\','/').Substring(8))" />
+
       <_WatchProjects Include="%(ProjectReference.Identity)" Condition="'%(ProjectReference.Watch)' != 'false'" />
     </ItemGroup>
 
@@ -77,6 +90,7 @@ Returns: @(Watch)
              BuildInParallel="true">
       <Output TaskParameter="TargetOutputs" ItemName="Watch" />
     </MSBuild>
+
   </Target>
 
 </Project>

src/BuiltInTools/dotnet-watch/DotNetWatchContext.cs

@@ -11,14 +11,16 @@ public class DotNetWatchContext
 
         public ProcessSpec ProcessSpec { get; set; }
 
-        public IFileSet FileSet { get; set; }
+        public FileSet FileSet { get; set; }
 
         public int Iteration { get; set; }
 
-        public string ChangedFile { get; set; }
+        public FileItem? ChangedFile { get; set; }
 
         public bool RequiresMSBuildRevaluation { get; set; }
 
         public bool SuppressMSBuildIncrementalism { get; set; }
+
+        public BrowserRefreshServer BrowserRefreshServer { get; set; }
     }
 }

src/BuiltInTools/dotnet-watch/DotNetWatchOptions.cs

@@ -0,0 +1,30 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+
+namespace Microsoft.DotNet.Watcher
+{
+    public record DotNetWatchOptions(
+        bool SuppressHandlingStaticContentFiles,
+        bool SuppressMSBuildIncrementalism,
+        bool SuppressLaunchBrowser,
+        bool SuppressBrowserRefresh,
+        bool RunningAsTest)
+    {
+        public static DotNetWatchOptions Default { get; } = new DotNetWatchOptions
+        (
+            SuppressHandlingStaticContentFiles: IsEnvironmentSet("DOTNET_WATCH_SUPPRESS_STATIC_FILE_HANDLING"),
+            SuppressMSBuildIncrementalism: IsEnvironmentSet("DOTNET_WATCH_SUPPRESS_MSBUILD_INCREMENTALISM"),
+            SuppressLaunchBrowser: IsEnvironmentSet("DOTNET_WATCH_SUPPRESS_LAUNCH_BROWSER"),
+            SuppressBrowserRefresh: IsEnvironmentSet("DOTNET_WATCH_SUPPRESS_BROWSER_REFRESH"),
+            RunningAsTest: IsEnvironmentSet("__DOTNET_WATCH_RUNNING_AS_TEST")
+        );
+
+        private static bool IsEnvironmentSet(string key)
+        {
+            var envValue = Environment.GetEnvironmentVariable(key);
+            return envValue == "1" || envValue == "true";
+        }
+    }
+}