diff --git a/README.md b/README.md
index 76be8f4fff..dcc20622b8 100644
--- a/README.md
+++ b/README.md
@@ -41,6 +41,7 @@ Usage:
   dotnet-format [options]
 
 Options:
+  -f, --folder       The folder to operate on. Cannot be used with the `--workspace` option.
   -w, --workspace    The solution or project file to operate on. If a file is not specified, the command will search
                      the current directory for one.
   -v, --verbosity    Set the verbosity level. Allowed values are q[uiet], m[inimal], n[ormal], d[etailed], and
@@ -56,6 +57,7 @@ Add `format` after `dotnet` and before the command arguments that you want to ru
 | Examples                                                 | Description                                                                                   |
 | -------------------------------------------------------- |---------------------------------------------------------------------------------------------- |
 | dotnet **format**                                        | Formats the project or solution in the current directory.                                     |
+| dotnet **format** -f <folder>                      | Formats a particular folder and subfolders.
 | dotnet **format** -w <workspace>                   | Formats a specific project or solution.                                                       | 
 | dotnet **format** -v diag                                | Formats with very verbose logging.                                                            |
 | dotnet **format** --files Programs.cs,Utility\Logging.cs | Formats the files Program.cs and Utility\Logging.cs                                           |
diff --git a/azure-pipelines-integration.yml b/azure-pipelines-integration.yml
index a379472e4a..003e3010cf 100644
--- a/azure-pipelines-integration.yml
+++ b/azure-pipelines-integration.yml
@@ -19,35 +19,35 @@ jobs:
       format:
         _repo: "https://github.com/dotnet/format"
         _repoName: "dotnet/format"
-        _sha: "b6db94c361b1ecd0558fc7429335ec01133773ed"
+        _sha: "4ff73616469a2aaa5ff07d11b7f6951eca83d76e"
       roslyn:
         _repo: "https://github.com/dotnet/roslyn"
         _repoName: "dotnet/roslyn"
-        _sha: "665dc224dcfefb66dce215ca0204363172b611ad"
+        _sha: "1bd191ea896b19e3b06a152f815f3a998e87049a"
       cli:
         _repo: "https://github.com/dotnet/cli"
         _repoName: "dotnet/cli"
-        _sha: "8d0f2a593ec98ccc1ef2141452d7dccadc34ac40"
+        _sha: "45f1c5f7f3275ff483c804e7c90bf61731a83e97"
       project-system:
         _repo: "https://github.com/dotnet/project-system"
         _repoName: "dotnet/project-system"
-        _sha: "80580ad27c5544f00f4abb9db930e698ce305285"
+        _sha: "fc3b12e47adaad6e4813dc600acf190156fecc24"
       msbuild:
         _repo: "https://github.com/Microsoft/msbuild"
         _repoName: "Microsoft/msbuild"
-        _sha: "d54d2e0180b99b7773f0fef2cdb03168f134d9aa"
+        _sha: "e92633a735b0e23e2cbf818d02ba89dd7a426f89"
       Blazor:
         _repo: "https://github.com/aspnet/Blazor"
         _repoName: "aspnet/Blazor"
-        _sha: "3addb6169afcae1b5c6a64de4a7cd02bd270ffed"
+        _sha: "7eeab316fa122b69a9bd777c93dcc78bc6a68905"
       EntityFrameworkCore:
         _repo: "https://github.com/aspnet/EntityFrameworkCore"
         _repoName: "aspnet/EntityFrameworkCore"
-        _sha: "090f385ffe4f2cd1a3e6b794523bdf574862c298"
+        _sha: "94f5bdf081f9a774f5d7f01bfa279bac26dab303"
       EntityFramework6:
         _repo: "https://github.com/aspnet/EntityFramework6"
         _repoName: "aspnet/EntityFramework6"
-        _sha: "936befcd88a4b58be6f35038248cd5337aca4967"
+        _sha: "9099ad2f6e5936ecdf549f88394b5a59fa75c869"
   timeoutInMinutes: 20
   steps:
     - script: eng\integration-test.cmd -repo '$(_repo)' -sha '$(_sha)' -testPath '$(Build.SourcesDirectory)\temp'
diff --git a/eng/format-verifier.ps1 b/eng/format-verifier.ps1
index cbe2a082ef..97378779d1 100644
--- a/eng/format-verifier.ps1
+++ b/eng/format-verifier.ps1
@@ -5,17 +5,7 @@ Param(
     [string]$testPath
 )
 
-function Clone-Repo([string]$repo, [string]$sha, [string]$repoPath) {
-    $currentLocation = Get-Location
-
-    git.exe clone $repo $repoPath
-
-    Set-Location $repoPath
-
-    git.exe checkout $sha
-
-    Set-Location $currentLocation
-}
+$currentLocation = Get-Location
 
 if (!(Test-Path $testPath)) {
     New-Item -ItemType Directory -Force -Path $testPath | Out-Null
@@ -27,19 +17,37 @@ try {
     $repoPath = Join-Path $testPath $folderName
 
     Write-Output "$(Get-Date) - Cloning $repoName."
-    Clone-Repo $repo $sha $repoPath
+    git.exe clone $repo $repoPath
+
+    Set-Location $repoPath
+
+    git.exe checkout $sha
 
     Write-Output "$(Get-Date) - Finding solutions."
-    $solutions = Get-ChildItem -Path $repoPath -Filter *.sln -Recurse -Depth 2 | Select-Object -ExpandProperty FullName | Where-Object { $_ -match '.sln$' }
+    $solutions = Get-ChildItem -Filter *.sln -Recurse -Depth 2 | Select-Object -ExpandProperty FullName | Where-Object { $_ -match '.sln$' }
+
+    # We invoke build.ps1 ourselves because running `restore.cmd` invokes the build.ps1
+    # in a child process which means added .NET Core SDKs aren't visible to this process.
+    if (Test-Path '.\eng\Build.ps1') {
+        Write-Output "$(Get-Date) - Running Build.ps1 -restore"
+        .\eng\Build.ps1 -restore
+    }
+    elseif (Test-Path '.\eng\common\Build.ps1') {
+        Write-Output "$(Get-Date) - Running Build.ps1 -restore"
+        .\eng\common\Build.ps1 -restore
+    }
 
     foreach ($solution in $solutions) {
+        $solutionPath = Split-Path $solution
         $solutionFile = Split-Path $solution -leaf
 
+        Set-Location $solutionPath
+
         Write-Output "$(Get-Date) - $solutionFile - Restoring"
         dotnet.exe restore $solution
 
         Write-Output "$(Get-Date) - $solutionFile - Formatting"
-        $output = dotnet.exe run -p .\src\dotnet-format.csproj -c Release -- -w $solution -v d --dry-run | Out-String
+        $output = dotnet.exe run -p "$currentLocation\src\dotnet-format.csproj" -c Release -- -w $solution -v d --dry-run | Out-String
         Write-Output $output.TrimEnd()
         
         if ($LastExitCode -ne 0) {
@@ -59,6 +67,8 @@ catch {
     exit -1
 }
 finally {
+    Set-Location $currentLocation
+
     Remove-Item $repoPath -Force -Recurse
     Write-Output "$(Get-Date) - Deleted $repoName."
 }
diff --git a/src/CodeFormatter.cs b/src/CodeFormatter.cs
index 2ab3299981..33bbf55c94 100644
--- a/src/CodeFormatter.cs
+++ b/src/CodeFormatter.cs
@@ -12,6 +12,7 @@
 using Microsoft.CodeAnalysis.Options;
 using Microsoft.CodeAnalysis.Tools.Utilities;
 using Microsoft.CodeAnalysis.Tools.Formatters;
+using Microsoft.CodeAnalysis.Tools.Workspaces;
 using Microsoft.Extensions.Logging;
 using Microsoft.VisualStudio.CodingConventions;
 
@@ -32,7 +33,7 @@ public static async Task<WorkspaceFormatResult> FormatWorkspaceAsync(
             ILogger logger,
             CancellationToken cancellationToken)
         {
-            var (workspaceFilePath, isSolution, logLevel, saveFormattedFiles, _, filesToFormat) = options;
+            var (workspaceFilePath, workspaceType, logLevel, saveFormattedFiles, _, filesToFormat) = options;
             var logWorkspaceWarnings = logLevel == LogLevel.Trace;
 
             logger.LogInformation(string.Format(Resources.Formatting_code_files_in_workspace_0, workspaceFilePath));
@@ -42,7 +43,7 @@ public static async Task<WorkspaceFormatResult> FormatWorkspaceAsync(
             var workspaceStopwatch = Stopwatch.StartNew();
 
             using (var workspace = await OpenWorkspaceAsync(
-                workspaceFilePath, isSolution, logWorkspaceWarnings, logger, cancellationToken).ConfigureAwait(false))
+                workspaceFilePath, workspaceType, filesToFormat, logWorkspaceWarnings, logger, cancellationToken).ConfigureAwait(false))
             {
                 if (workspace is null)
                 {
@@ -52,7 +53,7 @@ public static async Task<WorkspaceFormatResult> FormatWorkspaceAsync(
                 var loadWorkspaceMS = workspaceStopwatch.ElapsedMilliseconds;
                 logger.LogTrace(Resources.Complete_in_0_ms, workspaceStopwatch.ElapsedMilliseconds);
 
-                var projectPath = isSolution ? string.Empty : workspaceFilePath;
+                var projectPath = workspaceType == WorkspaceType.Project ? workspaceFilePath : string.Empty;
                 var solution = workspace.CurrentSolution;
 
                 logger.LogTrace(Resources.Determining_formattable_files);
@@ -101,8 +102,26 @@ public static async Task<WorkspaceFormatResult> FormatWorkspaceAsync(
         }
 
         private static async Task<Workspace> OpenWorkspaceAsync(
+            string workspacePath,
+            WorkspaceType workspaceType,
+            ImmutableHashSet<string> filesToFormat,
+            bool logWorkspaceWarnings,
+            ILogger logger,
+            CancellationToken cancellationToken)
+        {
+            if (workspaceType == WorkspaceType.Folder)
+            {
+                var folderWorkspace = FolderWorkspace.Create();
+                await folderWorkspace.OpenFolder(workspacePath, filesToFormat, cancellationToken);
+                return folderWorkspace;
+            }
+
+            return await OpenMSBuildWorkspaceAsync(workspacePath, workspaceType, logWorkspaceWarnings, logger, cancellationToken);
+        }
+
+        private static async Task<Workspace> OpenMSBuildWorkspaceAsync(
             string solutionOrProjectPath,
-            bool isSolution,
+            WorkspaceType workspaceType,
             bool logWorkspaceWarnings,
             ILogger logger,
             CancellationToken cancellationToken)
@@ -119,10 +138,8 @@ private static async Task<Workspace> OpenWorkspaceAsync(
             };
 
             var workspace = MSBuildWorkspace.Create(properties);
-            workspace.WorkspaceFailed += LogWorkspaceWarnings;
 
-            var projectPath = string.Empty;
-            if (isSolution)
+            if (workspaceType == WorkspaceType.Solution)
             {
                 await workspace.OpenSolutionAsync(solutionOrProjectPath, cancellationToken: cancellationToken).ConfigureAwait(false);
             }
@@ -131,7 +148,6 @@ private static async Task<Workspace> OpenWorkspaceAsync(
                 try
                 {
                     await workspace.OpenProjectAsync(solutionOrProjectPath, cancellationToken: cancellationToken).ConfigureAwait(false);
-                    projectPath = solutionOrProjectPath;
                 }
                 catch (InvalidOperationException)
                 {
@@ -141,25 +157,33 @@ private static async Task<Workspace> OpenWorkspaceAsync(
                 }
             }
 
-            workspace.WorkspaceFailed -= LogWorkspaceWarnings;
+            LogWorkspaceDiagnostics(logger, logWorkspaceWarnings, workspace.Diagnostics);
 
             return workspace;
+        }
 
-            void LogWorkspaceWarnings(object sender, WorkspaceDiagnosticEventArgs args)
+        private static void LogWorkspaceDiagnostics(ILogger logger, bool logWorkspaceWarnings, ImmutableList<WorkspaceDiagnostic> diagnostics)
+        {
+            if (!logWorkspaceWarnings)
             {
-                if (args.Diagnostic.Kind == WorkspaceDiagnosticKind.Failure)
+                if (diagnostics.Count > 0)
                 {
-                    return;
+                    logger.LogWarning(Resources.Warnings_were_encountered_while_loading_the_workspace_Set_the_verbosity_option_to_the_diagnostic_level_to_log_warnings);
                 }
 
-                if (!logWorkspaceWarnings)
+                return;
+            }
+
+            foreach (var diagnostic in diagnostics)
+            {
+                if (diagnostic.Kind == WorkspaceDiagnosticKind.Failure)
                 {
-                    logger.LogWarning(Resources.Warnings_were_encountered_while_loading_the_workspace_Set_the_verbosity_option_to_the_diagnostic_level_to_log_warnings);
-                    ((MSBuildWorkspace)sender).WorkspaceFailed -= LogWorkspaceWarnings;
-                    return;
+                    logger.LogError(diagnostic.Message);
+                }
+                else
+                {
+                    logger.LogWarning(diagnostic.Message);
                 }
-
-                logger.LogWarning(args.Diagnostic.Message);
             }
         }
 
@@ -212,8 +236,8 @@ private static async Task<Solution> RunCodeFormattersAsync(
                 fileCount += project.DocumentIds.Count;
 
                 // Get project documents and options with .editorconfig settings applied.
-                var getProjectDocuments = project.DocumentIds.Select(documentId => Task.Run(async () => await GetDocumentAndOptions(
-                    project, documentId, filesToFormat, codingConventionsManager, optionsApplier, cancellationToken).ConfigureAwait(false), cancellationToken));
+                var getProjectDocuments = project.DocumentIds.Select(documentId => GetDocumentAndOptions(
+                    project, documentId, filesToFormat, codingConventionsManager, optionsApplier, cancellationToken));
                 getDocumentsAndOptions.AddRange(getProjectDocuments);
             }
 
@@ -248,7 +272,7 @@ private static async Task<Solution> RunCodeFormattersAsync(
             return (fileCount, formattableFiles.ToImmutableArray());
         }
 
-        private static async Task<(Document, OptionSet, ICodingConventionsSnapshot, bool)> GetDocumentAndOptions(
+        private static async    Task<(Document, OptionSet, ICodingConventionsSnapshot, bool)> GetDocumentAndOptions(
             Project project,
             DocumentId documentId,
             ImmutableHashSet<string> filesToFormat,
diff --git a/src/FormatOptions.cs b/src/FormatOptions.cs
index 348ba40039..0c4a27a358 100644
--- a/src/FormatOptions.cs
+++ b/src/FormatOptions.cs
@@ -1,4 +1,6 @@
-using System.Collections.Immutable;
+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the MIT license.  See License.txt in the project root for license information.
+
+using System.Collections.Immutable;
 using Microsoft.Extensions.Logging;
 
 namespace Microsoft.CodeAnalysis.Tools
@@ -6,7 +8,7 @@ namespace Microsoft.CodeAnalysis.Tools
     internal class FormatOptions
     {
         public string WorkspaceFilePath { get; }
-        public bool IsSolution { get; }
+        public WorkspaceType WorkspaceType { get; }
         public LogLevel LogLevel { get; }
         public bool SaveFormattedFiles { get; }
         public bool ChangesAreErrors { get; }
@@ -14,14 +16,14 @@ internal class FormatOptions
 
         public FormatOptions(
             string workspaceFilePath,
-            bool isSolution,
+            WorkspaceType workspaceType,
             LogLevel logLevel,
             bool saveFormattedFiles,
             bool changesAreErrors,
             ImmutableHashSet<string> filesToFormat)
         {
             WorkspaceFilePath = workspaceFilePath;
-            IsSolution = isSolution;
+            WorkspaceType = workspaceType;
             LogLevel = logLevel;
             SaveFormattedFiles = saveFormattedFiles;
             ChangesAreErrors = changesAreErrors;
@@ -30,14 +32,14 @@ public FormatOptions(
 
         public void Deconstruct(
             out string workspaceFilePath,
-            out bool isSolution,
+            out WorkspaceType workspaceType,
             out LogLevel logLevel,
             out bool saveFormattedFiles,
             out bool changesAreErrors,
             out ImmutableHashSet<string> filesToFormat)
         {
             workspaceFilePath = WorkspaceFilePath;
-            isSolution = IsSolution;
+            workspaceType = WorkspaceType;
             logLevel = LogLevel;
             saveFormattedFiles = SaveFormattedFiles;
             changesAreErrors = ChangesAreErrors;
diff --git a/src/Formatters/DocumentFormatter.cs b/src/Formatters/DocumentFormatter.cs
index c2c0a5f6bf..279ba2fc69 100644
--- a/src/Formatters/DocumentFormatter.cs
+++ b/src/Formatters/DocumentFormatter.cs
@@ -78,8 +78,6 @@ protected abstract Task<SourceText> FormatFileAsync(
             ILogger logger,
             CancellationToken cancellationToken)
         {
-            logger.LogTrace(Resources.Formatting_code_file_0, Path.GetFileName(document.FilePath));
-
             var originalSourceText = await document.GetTextAsync(cancellationToken).ConfigureAwait(false);
             var formattedSourceText = await FormatFileAsync(document, originalSourceText, options, codingConventions, formatOptions, logger, cancellationToken).ConfigureAwait(false);
 
@@ -113,7 +111,7 @@ private async Task<Solution> ApplyFileChangesAsync(
                     continue;
                 }
 
-                if (!formatOptions.SaveFormattedFiles)
+                if (!formatOptions.SaveFormattedFiles || formatOptions.LogLevel == LogLevel.Trace)
                 {
                     // Log formatting changes as errors when we are doing a dry-run.
                     LogFormattingChanges(formatOptions.WorkspaceFilePath, document.FilePath, originalText, formattedText, formatOptions.ChangesAreErrors, logger);
diff --git a/src/Program.cs b/src/Program.cs
index 61dee16a04..270b231b9e 100644
--- a/src/Program.cs
+++ b/src/Program.cs
@@ -30,6 +30,7 @@ private static async Task<int> Main(string[] args)
                 .RegisterWithDotnetSuggest()
                 .UseParseErrorReporting()
                 .UseExceptionHandler()
+                .AddOption(new Option(new[] { "-f", "--folder" }, Resources.The_folder_to_operate_on_Cannot_be_used_with_the_workspace_option, new Argument<string>(() => null)))
                 .AddOption(new Option(new[] { "-w", "--workspace" }, Resources.The_solution_or_project_file_to_operate_on_If_a_file_is_not_specified_the_command_will_search_the_current_directory_for_one, new Argument<string>(() => null)))
                 .AddOption(new Option(new[] { "-v", "--verbosity" }, Resources.Set_the_verbosity_level_Allowed_values_are_quiet_minimal_normal_detailed_and_diagnostic, new Argument<string>() { Arity = ArgumentArity.ExactlyOne }.FromAmong(_verbosityLevels)))
                 .AddOption(new Option(new[] { "--dry-run" }, Resources.Format_files_but_do_not_save_changes_to_disk, new Argument<bool>()))
@@ -41,7 +42,7 @@ private static async Task<int> Main(string[] args)
             return await parser.InvokeAsync(args).ConfigureAwait(false);
         }
 
-        public static async Task<int> Run(string workspace, string verbosity, bool dryRun, bool check, string files, IConsole console = null)
+        public static async Task<int> Run(string folder, string workspace, string verbosity, bool dryRun, bool check, string files, IConsole console = null)
         {
             // Setup logging.
             var serviceCollection = new ServiceCollection();
@@ -65,16 +66,41 @@ public static async Task<int> Run(string workspace, string verbosity, bool dryRu
             {
                 currentDirectory = Environment.CurrentDirectory;
 
-                var workingDirectory = Directory.GetCurrentDirectory();
-                var (isSolution, workspacePath) = MSBuildWorkspaceFinder.FindWorkspace(workingDirectory, workspace);
+                string workspaceDirectory;
+                string workspacePath;
+                WorkspaceType workspaceType;
 
-                // To ensure we get the version of MSBuild packaged with the dotnet SDK used by the
-                // workspace, use its directory as our working directory which will take into account
-                // a global.json if present.
-                var workspaceDirectory = Path.GetDirectoryName(workspacePath);
-                Environment.CurrentDirectory = workingDirectory;
+                if (!string.IsNullOrEmpty(folder) && !string.IsNullOrEmpty(workspace))
+                {
+                    logger.LogWarning(Resources.Cannot_specify_both_folder_and_workspace_options);
+                    return 1;
+                }
+
+                if (!string.IsNullOrEmpty(folder))
+                {
+                    folder = Path.GetFullPath(folder, Environment.CurrentDirectory);
+                    workspacePath = folder;
+                    workspaceDirectory = workspacePath;
+                    workspaceType = WorkspaceType.Folder;
+                }
+                else
+                {
+                    var (isSolution, workspaceFilePath) = MSBuildWorkspaceFinder.FindWorkspace(currentDirectory, workspace);
+
+                    workspacePath = workspaceFilePath;
+                    workspaceType = isSolution
+                        ? WorkspaceType.Solution
+                        : WorkspaceType.Project;
 
-                var filesToFormat = GetFilesToFormat(files);
+                    // To ensure we get the version of MSBuild packaged with the dotnet SDK used by the
+                    // workspace, use its directory as our working directory which will take into account
+                    // a global.json if present.
+                    workspaceDirectory = Path.GetDirectoryName(workspacePath);
+                }
+
+                Environment.CurrentDirectory = workspaceDirectory;
+
+                var filesToFormat = GetFilesToFormat(files, folder);
 
                 // Since we are running as a dotnet tool we should be able to find an instance of
                 // MSBuild in a .NET Core SDK.
@@ -90,7 +116,7 @@ public static async Task<int> Run(string workspace, string verbosity, bool dryRu
 
                 var formatOptions = new FormatOptions(
                     workspacePath,
-                    isSolution,
+                    workspaceType,
                     logLevel,
                     saveFormattedFiles: !dryRun,
                     changesAreErrors: check,
@@ -164,16 +190,26 @@ private static void ConfigureServices(ServiceCollection serviceCollection, ICons
         /// <summary>
         /// Converts a comma-separated list of relative file paths to a hashmap of full file paths.
         /// </summary>
-        internal static ImmutableHashSet<string> GetFilesToFormat(string files)
+        internal static ImmutableHashSet<string> GetFilesToFormat(string files, string folder)
         {
             if (string.IsNullOrEmpty(files))
             {
                 return ImmutableHashSet.Create<string>();
             }
 
-            return files.Split(',')
-                .Select(path => Path.GetFullPath(path, Environment.CurrentDirectory))
-                .ToImmutableHashSet(StringComparer.OrdinalIgnoreCase);
+            if (string.IsNullOrEmpty(folder))
+            {
+                return files.Split(',')
+                    .Select(path => Path.GetFullPath(path, Environment.CurrentDirectory))
+                    .ToImmutableHashSet(StringComparer.OrdinalIgnoreCase);
+            }
+            else
+            {
+                return files.Split(',')
+                    .Select(path => Path.GetFullPath(path, Environment.CurrentDirectory))
+                    .Where(path => path.StartsWith(folder))
+                    .ToImmutableHashSet(StringComparer.OrdinalIgnoreCase);
+            }
         }
     }
 }
diff --git a/src/Resources.resx b/src/Resources.resx
index 2a86be8ca3..a7331817aa 100644
--- a/src/Resources.resx
+++ b/src/Resources.resx
@@ -204,4 +204,10 @@
   <data name="Fix_file_encoding" xml:space="preserve">
     <value>Fix file encoding.</value>
   </data>
+  <data name="The_folder_to_operate_on_Cannot_be_used_with_the_workspace_option" xml:space="preserve">
+    <value>The folder to operate on. Cannot be used with the `--workspace` option.</value>
+  </data>
+  <data name="Cannot_specify_both_folder_and_workspace_options" xml:space="preserve">
+    <value>Cannot specify both folder and workspace options.</value>
+  </data>
 </root>
\ No newline at end of file
diff --git a/src/WorkspaceType.cs b/src/WorkspaceType.cs
new file mode 100644
index 0000000000..2069a22d84
--- /dev/null
+++ b/src/WorkspaceType.cs
@@ -0,0 +1,11 @@
+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the MIT license.  See License.txt in the project root for license information.
+
+namespace Microsoft.CodeAnalysis.Tools
+{
+    internal enum WorkspaceType
+    {
+        Folder,
+        Project,
+        Solution
+    }
+}
diff --git a/src/Workspaces/FolderWorkspace.cs b/src/Workspaces/FolderWorkspace.cs
new file mode 100644
index 0000000000..1f8a068ac8
--- /dev/null
+++ b/src/Workspaces/FolderWorkspace.cs
@@ -0,0 +1,82 @@
+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the MIT license.  See License.txt in the project root for license information.
+
+using System;
+using System.Collections.Immutable;
+using System.Diagnostics;
+using System.IO;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.Host;
+using Microsoft.CodeAnalysis.Host.Mef;
+using Microsoft.CodeAnalysis.Text;
+
+namespace Microsoft.CodeAnalysis.Tools.Workspaces
+{
+    internal sealed partial class FolderWorkspace : Workspace
+    {
+        private static readonly Encoding DefaultEncoding = new UTF8Encoding(encoderShouldEmitUTF8Identifier: false);
+
+        private FolderWorkspace(HostServices hostServices)
+            : base(hostServices, "Folder")
+        {
+        }
+
+        public static FolderWorkspace Create()
+        {
+            return Create(MSBuildMefHostServices.DefaultServices);
+        }
+
+        public static FolderWorkspace Create(HostServices hostServices)
+        {
+            return new FolderWorkspace(hostServices);
+        }
+
+        public async Task<Solution> OpenFolder(string folderPath, ImmutableHashSet<string> filesToInclude, CancellationToken cancellationToken)
+        {
+            if (string.IsNullOrEmpty(folderPath) || !Directory.Exists(folderPath))
+            {
+                throw new ArgumentException($"Folder '{folderPath}' does not exist.", nameof(folderPath));
+            }
+
+            ClearSolution();
+
+            var solutionInfo = await FolderSolutionLoader.LoadSolutionInfoAsync(folderPath, filesToInclude, cancellationToken).ConfigureAwait(false);
+
+            OnSolutionAdded(solutionInfo);
+
+            return CurrentSolution;
+        }
+
+        public override bool CanApplyChange(ApplyChangesKind feature)
+        {
+            // Whitespace formatting should only produce document changes; no other types of changes are supported.
+            return feature == ApplyChangesKind.ChangeDocument;
+        }
+
+        protected override void ApplyDocumentTextChanged(DocumentId documentId, SourceText text)
+        {
+            var document = this.CurrentSolution.GetDocument(documentId);
+            if (document != null)
+            {
+                SaveDocumentText(documentId, document.FilePath, text, text.Encoding);
+                OnDocumentTextChanged(documentId, text, PreservationMode.PreserveValue);
+            }
+        }
+
+        private void SaveDocumentText(DocumentId id, string fullPath, SourceText newText, Encoding encoding)
+        {
+            try
+            {
+                using (var writer = new StreamWriter(fullPath, append: false, encoding))
+                {
+                    newText.Write(writer);
+                }
+            }
+            catch (IOException exception)
+            {
+                OnWorkspaceFailed(new DocumentDiagnostic(WorkspaceDiagnosticKind.Failure, exception.Message, id));
+            }
+        }
+    }
+}
diff --git a/src/Workspaces/FolderWorkspace_CSharpProjectLoader.cs b/src/Workspaces/FolderWorkspace_CSharpProjectLoader.cs
new file mode 100644
index 0000000000..de19b035f1
--- /dev/null
+++ b/src/Workspaces/FolderWorkspace_CSharpProjectLoader.cs
@@ -0,0 +1,13 @@
+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the MIT license.  See License.txt in the project root for license information.
+
+namespace Microsoft.CodeAnalysis.Tools.Workspaces
+{
+    internal sealed partial class FolderWorkspace : Workspace
+    {
+        private sealed class CSharpProjectLoader : ProjectLoader
+        {
+            public override string Language => LanguageNames.CSharp;
+            public override string FileExtension => ".cs";
+        }
+    }
+}
diff --git a/src/Workspaces/FolderWorkspace_FolderSolutionLoader.cs b/src/Workspaces/FolderWorkspace_FolderSolutionLoader.cs
new file mode 100644
index 0000000000..db2a54a57b
--- /dev/null
+++ b/src/Workspaces/FolderWorkspace_FolderSolutionLoader.cs
@@ -0,0 +1,46 @@
+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the MIT license.  See License.txt in the project root for license information.
+
+using System.Collections.Immutable;
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Microsoft.CodeAnalysis.Tools.Workspaces
+{
+    internal sealed partial class FolderWorkspace : Workspace
+    {
+        private static class FolderSolutionLoader
+        {
+            private static ImmutableArray<ProjectLoader> ProjectLoaders
+                => ImmutableArray.Create<ProjectLoader>(new CSharpProjectLoader(), new VisualBasicProjectLoader());
+
+            public static async Task<SolutionInfo> LoadSolutionInfoAsync(string folderPath, ImmutableHashSet<string> filesToInclude, CancellationToken cancellationToken)
+            {
+                var absoluteFolderPath = Path.IsPathFullyQualified(folderPath)
+                    ? folderPath
+                    : Path.GetFullPath(folderPath, Directory.GetCurrentDirectory());
+
+                var projectInfos = ImmutableArray.CreateBuilder<ProjectInfo>(ProjectLoaders.Length);
+
+                // Create projects for each of the supported languages.
+                foreach (var loader in ProjectLoaders)
+                {
+                    var projectInfo = await loader.LoadProjectInfoAsync(folderPath, filesToInclude, cancellationToken);
+                    if (projectInfo is null)
+                    {
+                        continue;
+                    }
+
+                    projectInfos.Add(projectInfo);
+                }
+
+                // Construct workspace from loaded project infos.
+                return SolutionInfo.Create(
+                    SolutionId.CreateNewId(debugName: absoluteFolderPath),
+                    version: default,
+                    absoluteFolderPath,
+                    projectInfos);
+            }
+        }
+    }
+}
diff --git a/src/Workspaces/FolderWorkspace_ProjectLoader.cs b/src/Workspaces/FolderWorkspace_ProjectLoader.cs
new file mode 100644
index 0000000000..8ed30b1d75
--- /dev/null
+++ b/src/Workspaces/FolderWorkspace_ProjectLoader.cs
@@ -0,0 +1,77 @@
+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the MIT license.  See License.txt in the project root for license information.
+
+using System.Collections.Immutable;
+using System.IO;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Microsoft.CodeAnalysis.Tools.Workspaces
+{
+    internal sealed partial class FolderWorkspace : Workspace
+    {
+        private abstract class ProjectLoader
+        {
+            public abstract string Language { get; }
+            public abstract string FileExtension { get; }
+            public virtual string ProjectName => $"{Language}{FileExtension}proj";
+
+            public virtual async Task<ProjectInfo> LoadProjectInfoAsync(string folderPath, ImmutableHashSet<string> filesToInclude, CancellationToken cancellationToken)
+            {
+                var projectId = ProjectId.CreateNewId(debugName: folderPath);
+
+                var documents = await LoadDocumentInfosAsync(projectId, folderPath, FileExtension, filesToInclude);
+                if (documents.IsDefaultOrEmpty)
+                {
+                    return null;
+                }
+
+                return ProjectInfo.Create(
+                    projectId,
+                    version: default,
+                    name: ProjectName,
+                    assemblyName: folderPath,
+                    Language,
+                    filePath: folderPath,
+                    documents: documents);
+            }
+
+            private static Task<ImmutableArray<DocumentInfo>> LoadDocumentInfosAsync(ProjectId projectId, string folderPath, string fileExtension, ImmutableHashSet<string> filesToInclude)
+            {
+                return Task.Run(() =>
+                {
+                    string[] filePaths;
+                    if (filesToInclude.Count == 0)
+                    {
+                        filePaths = Directory.GetFiles(folderPath, $"*{fileExtension}", SearchOption.AllDirectories);
+                    }
+                    else
+                    {
+                        filePaths = filesToInclude.Where(
+                            filePath => filePath.EndsWith(fileExtension) && File.Exists(filePath)).ToArray();
+                    }
+
+                    if (filePaths.Length == 0)
+                    {
+                        return ImmutableArray<DocumentInfo>.Empty;
+                    }
+
+                    var documentInfos = ImmutableArray.CreateBuilder<DocumentInfo>(filePaths.Length);
+
+                    foreach (var filePath in filePaths)
+                    {
+                        var documentInfo = DocumentInfo.Create(
+                            DocumentId.CreateNewId(projectId, debugName: filePath),
+                            name: Path.GetFileName(filePath),
+                            loader: new FileTextLoader(filePath, DefaultEncoding),
+                            filePath: filePath);
+
+                        documentInfos.Add(documentInfo);
+                    }
+
+                    return documentInfos.ToImmutableArray();
+                });
+            }
+        }
+    }
+}
diff --git a/src/Workspaces/FolderWorkspace_VisualBasicProjectLoader.cs b/src/Workspaces/FolderWorkspace_VisualBasicProjectLoader.cs
new file mode 100644
index 0000000000..1f50e45af6
--- /dev/null
+++ b/src/Workspaces/FolderWorkspace_VisualBasicProjectLoader.cs
@@ -0,0 +1,13 @@
+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the MIT license.  See License.txt in the project root for license information.
+
+namespace Microsoft.CodeAnalysis.Tools.Workspaces
+{
+    internal sealed partial class FolderWorkspace : Workspace
+    {
+        private sealed class VisualBasicProjectLoader : ProjectLoader
+        {
+            public override string Language => LanguageNames.VisualBasic;
+            public override string FileExtension => ".vb";
+        }
+    }
+}
diff --git a/src/xlf/Resources.cs.xlf b/src/xlf/Resources.cs.xlf
index 48fc81ae18..1ec437e41c 100644
--- a/src/xlf/Resources.cs.xlf
+++ b/src/xlf/Resources.cs.xlf
@@ -17,6 +17,11 @@
         <target state="translated">{0} obsahuje jak soubor projektu MSBuild, tak soubor řešení. Určete, který soubor chcete použít, pomocí parametru --workspace.</target>
         <note />
       </trans-unit>
+      <trans-unit id="Cannot_specify_both_folder_and_workspace_options">
+        <source>Cannot specify both folder and workspace options.</source>
+        <target state="new">Cannot specify both folder and workspace options.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Complete_in_0_ms">
         <source>Complete in {0}ms.</source>
         <target state="new">Complete in {0}ms.</target>
@@ -122,6 +127,11 @@
         <target state="translated">Soubor {0} zřejmě není platný soubor projektu nebo řešení.</target>
         <note />
       </trans-unit>
+      <trans-unit id="The_folder_to_operate_on_Cannot_be_used_with_the_workspace_option">
+        <source>The folder to operate on. Cannot be used with the `--workspace` option.</source>
+        <target state="new">The folder to operate on. Cannot be used with the `--workspace` option.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="The_project_file_0_does_not_exist">
         <source>The project file '{0}' does not exist.</source>
         <target state="translated">Soubor projektu {0} neexistuje.</target>
diff --git a/src/xlf/Resources.de.xlf b/src/xlf/Resources.de.xlf
index 75716acc73..b356ce8fd4 100644
--- a/src/xlf/Resources.de.xlf
+++ b/src/xlf/Resources.de.xlf
@@ -17,6 +17,11 @@
         <target state="translated">In "{0}" wurden eine MSBuild-Projektdatei und eine Projektmappe gefunden. Geben Sie mit der Option "--workspace" an, welche verwendet werden soll.</target>
         <note />
       </trans-unit>
+      <trans-unit id="Cannot_specify_both_folder_and_workspace_options">
+        <source>Cannot specify both folder and workspace options.</source>
+        <target state="new">Cannot specify both folder and workspace options.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Complete_in_0_ms">
         <source>Complete in {0}ms.</source>
         <target state="new">Complete in {0}ms.</target>
@@ -122,6 +127,11 @@
         <target state="translated">Die Datei "{0}" ist weder ein gültiges Projekt noch eine Projektmappendatei.</target>
         <note />
       </trans-unit>
+      <trans-unit id="The_folder_to_operate_on_Cannot_be_used_with_the_workspace_option">
+        <source>The folder to operate on. Cannot be used with the `--workspace` option.</source>
+        <target state="new">The folder to operate on. Cannot be used with the `--workspace` option.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="The_project_file_0_does_not_exist">
         <source>The project file '{0}' does not exist.</source>
         <target state="translated">Die Projektdatei "{0}" ist nicht vorhanden.</target>
diff --git a/src/xlf/Resources.es.xlf b/src/xlf/Resources.es.xlf
index c292b95efb..8b37b5fcd2 100644
--- a/src/xlf/Resources.es.xlf
+++ b/src/xlf/Resources.es.xlf
@@ -17,6 +17,11 @@
         <target state="translated">Se encontró un archivo de proyecto y un archivo de solución MSBuild en "{0}". Especifique cuál debe usarse con la opción --workspace.</target>
         <note />
       </trans-unit>
+      <trans-unit id="Cannot_specify_both_folder_and_workspace_options">
+        <source>Cannot specify both folder and workspace options.</source>
+        <target state="new">Cannot specify both folder and workspace options.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Complete_in_0_ms">
         <source>Complete in {0}ms.</source>
         <target state="new">Complete in {0}ms.</target>
@@ -122,6 +127,11 @@
         <target state="translated">El archivo "{0}" no parece ser un proyecto o archivo de solución válido.</target>
         <note />
       </trans-unit>
+      <trans-unit id="The_folder_to_operate_on_Cannot_be_used_with_the_workspace_option">
+        <source>The folder to operate on. Cannot be used with the `--workspace` option.</source>
+        <target state="new">The folder to operate on. Cannot be used with the `--workspace` option.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="The_project_file_0_does_not_exist">
         <source>The project file '{0}' does not exist.</source>
         <target state="translated">El archivo de proyecto "{0}" no existe.</target>
diff --git a/src/xlf/Resources.fr.xlf b/src/xlf/Resources.fr.xlf
index 528b9962ee..5345117728 100644
--- a/src/xlf/Resources.fr.xlf
+++ b/src/xlf/Resources.fr.xlf
@@ -17,6 +17,11 @@
         <target state="translated">Un fichier projet et un fichier solution MSBuild ont été trouvés dans '{0}'. Spécifiez celui à utiliser avec l'option --workspace.</target>
         <note />
       </trans-unit>
+      <trans-unit id="Cannot_specify_both_folder_and_workspace_options">
+        <source>Cannot specify both folder and workspace options.</source>
+        <target state="new">Cannot specify both folder and workspace options.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Complete_in_0_ms">
         <source>Complete in {0}ms.</source>
         <target state="new">Complete in {0}ms.</target>
@@ -122,6 +127,11 @@
         <target state="translated">Le fichier '{0}' ne semble pas être un fichier projet ou solution valide.</target>
         <note />
       </trans-unit>
+      <trans-unit id="The_folder_to_operate_on_Cannot_be_used_with_the_workspace_option">
+        <source>The folder to operate on. Cannot be used with the `--workspace` option.</source>
+        <target state="new">The folder to operate on. Cannot be used with the `--workspace` option.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="The_project_file_0_does_not_exist">
         <source>The project file '{0}' does not exist.</source>
         <target state="translated">Le fichier projet '{0}' n'existe pas.</target>
diff --git a/src/xlf/Resources.it.xlf b/src/xlf/Resources.it.xlf
index d5ec868f7c..d472a97f7f 100644
--- a/src/xlf/Resources.it.xlf
+++ b/src/xlf/Resources.it.xlf
@@ -17,6 +17,11 @@
         <target state="translated">In '{0}' sono stati trovati sia un file di progetto che un file di soluzione MSBuild. Per specificare quello desiderato, usare l'opzione --workspace.</target>
         <note />
       </trans-unit>
+      <trans-unit id="Cannot_specify_both_folder_and_workspace_options">
+        <source>Cannot specify both folder and workspace options.</source>
+        <target state="new">Cannot specify both folder and workspace options.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Complete_in_0_ms">
         <source>Complete in {0}ms.</source>
         <target state="new">Complete in {0}ms.</target>
@@ -122,6 +127,11 @@
         <target state="translated">Il file '{0}' non sembra essere un file di progetto o di soluzione valido.</target>
         <note />
       </trans-unit>
+      <trans-unit id="The_folder_to_operate_on_Cannot_be_used_with_the_workspace_option">
+        <source>The folder to operate on. Cannot be used with the `--workspace` option.</source>
+        <target state="new">The folder to operate on. Cannot be used with the `--workspace` option.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="The_project_file_0_does_not_exist">
         <source>The project file '{0}' does not exist.</source>
         <target state="translated">Il file di progetto '{0}' non esiste.</target>
diff --git a/src/xlf/Resources.ja.xlf b/src/xlf/Resources.ja.xlf
index 509ee5ad9a..53f5fe83e0 100644
--- a/src/xlf/Resources.ja.xlf
+++ b/src/xlf/Resources.ja.xlf
@@ -17,6 +17,11 @@
         <target state="translated">MSBuild プロジェクト ファイルとソリューション ファイルが '{0}' で見つかりました。使用するファイルを --workspace オプションで指定してください。</target>
         <note />
       </trans-unit>
+      <trans-unit id="Cannot_specify_both_folder_and_workspace_options">
+        <source>Cannot specify both folder and workspace options.</source>
+        <target state="new">Cannot specify both folder and workspace options.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Complete_in_0_ms">
         <source>Complete in {0}ms.</source>
         <target state="new">Complete in {0}ms.</target>
@@ -122,6 +127,11 @@
         <target state="translated">ファイル '{0}' が、有効なプロジェクト ファイルまたはソリューション ファイルではない可能性があります。</target>
         <note />
       </trans-unit>
+      <trans-unit id="The_folder_to_operate_on_Cannot_be_used_with_the_workspace_option">
+        <source>The folder to operate on. Cannot be used with the `--workspace` option.</source>
+        <target state="new">The folder to operate on. Cannot be used with the `--workspace` option.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="The_project_file_0_does_not_exist">
         <source>The project file '{0}' does not exist.</source>
         <target state="translated">プロジェクト ファイル '{0}' が存在しません。</target>
diff --git a/src/xlf/Resources.ko.xlf b/src/xlf/Resources.ko.xlf
index 4ba7dc9fad..a7ef729016 100644
--- a/src/xlf/Resources.ko.xlf
+++ b/src/xlf/Resources.ko.xlf
@@ -17,6 +17,11 @@
         <target state="translated">'{0}'에 MSBuild 프로젝트 파일 및 솔루션 파일이 모두 있습니다. --workspace 옵션에 사용할 파일을 지정하세요.</target>
         <note />
       </trans-unit>
+      <trans-unit id="Cannot_specify_both_folder_and_workspace_options">
+        <source>Cannot specify both folder and workspace options.</source>
+        <target state="new">Cannot specify both folder and workspace options.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Complete_in_0_ms">
         <source>Complete in {0}ms.</source>
         <target state="new">Complete in {0}ms.</target>
@@ -122,6 +127,11 @@
         <target state="translated">'{0}' 파일은 유효한 프로젝트 또는 솔루션 파일이 아닌 것 같습니다.</target>
         <note />
       </trans-unit>
+      <trans-unit id="The_folder_to_operate_on_Cannot_be_used_with_the_workspace_option">
+        <source>The folder to operate on. Cannot be used with the `--workspace` option.</source>
+        <target state="new">The folder to operate on. Cannot be used with the `--workspace` option.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="The_project_file_0_does_not_exist">
         <source>The project file '{0}' does not exist.</source>
         <target state="translated">프로젝트 파일 '{0}'이(가) 없습니다.</target>
diff --git a/src/xlf/Resources.pl.xlf b/src/xlf/Resources.pl.xlf
index 653d8745ac..069c24b4fe 100644
--- a/src/xlf/Resources.pl.xlf
+++ b/src/xlf/Resources.pl.xlf
@@ -17,6 +17,11 @@
         <target state="translated">W elemencie „{0}” znaleziono zarówno plik rozwiązania, jak i plik projektu MSBuild. Określ plik do użycia za pomocą opcji --workspace.</target>
         <note />
       </trans-unit>
+      <trans-unit id="Cannot_specify_both_folder_and_workspace_options">
+        <source>Cannot specify both folder and workspace options.</source>
+        <target state="new">Cannot specify both folder and workspace options.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Complete_in_0_ms">
         <source>Complete in {0}ms.</source>
         <target state="new">Complete in {0}ms.</target>
@@ -122,6 +127,11 @@
         <target state="translated">Plik „{0}” prawdopodobnie nie jest prawidłowym plikiem projektu lub rozwiązania.</target>
         <note />
       </trans-unit>
+      <trans-unit id="The_folder_to_operate_on_Cannot_be_used_with_the_workspace_option">
+        <source>The folder to operate on. Cannot be used with the `--workspace` option.</source>
+        <target state="new">The folder to operate on. Cannot be used with the `--workspace` option.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="The_project_file_0_does_not_exist">
         <source>The project file '{0}' does not exist.</source>
         <target state="translated">Plik projektu „{0}” nie istnieje.</target>
diff --git a/src/xlf/Resources.pt-BR.xlf b/src/xlf/Resources.pt-BR.xlf
index 47ee54d398..26e4a79595 100644
--- a/src/xlf/Resources.pt-BR.xlf
+++ b/src/xlf/Resources.pt-BR.xlf
@@ -17,6 +17,11 @@
         <target state="translated">Foram encontrados um arquivo de solução e um arquivo de projeto MSBuild em '{0}'. Especifique qual usar com a opção --espaço de trabalho.</target>
         <note />
       </trans-unit>
+      <trans-unit id="Cannot_specify_both_folder_and_workspace_options">
+        <source>Cannot specify both folder and workspace options.</source>
+        <target state="new">Cannot specify both folder and workspace options.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Complete_in_0_ms">
         <source>Complete in {0}ms.</source>
         <target state="new">Complete in {0}ms.</target>
@@ -122,6 +127,11 @@
         <target state="translated">O arquivo '{0}' parece não ser um projeto válido ou o arquivo de solução.</target>
         <note />
       </trans-unit>
+      <trans-unit id="The_folder_to_operate_on_Cannot_be_used_with_the_workspace_option">
+        <source>The folder to operate on. Cannot be used with the `--workspace` option.</source>
+        <target state="new">The folder to operate on. Cannot be used with the `--workspace` option.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="The_project_file_0_does_not_exist">
         <source>The project file '{0}' does not exist.</source>
         <target state="translated">O arquivo de projeto '{0}' não existe.</target>
diff --git a/src/xlf/Resources.ru.xlf b/src/xlf/Resources.ru.xlf
index dcf0dfa05a..5192bf1779 100644
--- a/src/xlf/Resources.ru.xlf
+++ b/src/xlf/Resources.ru.xlf
@@ -17,6 +17,11 @@
         <target state="translated">В "{0}" обнаружены как файл проекта, так и файл решения MSBuild. Укажите используемый файл с помощью параметра --workspace.</target>
         <note />
       </trans-unit>
+      <trans-unit id="Cannot_specify_both_folder_and_workspace_options">
+        <source>Cannot specify both folder and workspace options.</source>
+        <target state="new">Cannot specify both folder and workspace options.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Complete_in_0_ms">
         <source>Complete in {0}ms.</source>
         <target state="new">Complete in {0}ms.</target>
@@ -122,6 +127,11 @@
         <target state="translated">Файл "{0}" не является допустимым файлом проекта или решения.</target>
         <note />
       </trans-unit>
+      <trans-unit id="The_folder_to_operate_on_Cannot_be_used_with_the_workspace_option">
+        <source>The folder to operate on. Cannot be used with the `--workspace` option.</source>
+        <target state="new">The folder to operate on. Cannot be used with the `--workspace` option.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="The_project_file_0_does_not_exist">
         <source>The project file '{0}' does not exist.</source>
         <target state="translated">Файл проекта "{0}" не существует.</target>
diff --git a/src/xlf/Resources.tr.xlf b/src/xlf/Resources.tr.xlf
index fb42711278..fcf937673d 100644
--- a/src/xlf/Resources.tr.xlf
+++ b/src/xlf/Resources.tr.xlf
@@ -17,6 +17,11 @@
         <target state="translated">Hem bir MSBuild proje dosyası ve çözüm dosyası '{0}' içinde bulundu. Hangi--çalışma alanı seçeneği ile kullanmak için belirtin.</target>
         <note />
       </trans-unit>
+      <trans-unit id="Cannot_specify_both_folder_and_workspace_options">
+        <source>Cannot specify both folder and workspace options.</source>
+        <target state="new">Cannot specify both folder and workspace options.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Complete_in_0_ms">
         <source>Complete in {0}ms.</source>
         <target state="new">Complete in {0}ms.</target>
@@ -122,6 +127,11 @@
         <target state="translated">'{0}' dosyası geçerli proje veya çözüm dosyası gibi görünmüyor.</target>
         <note />
       </trans-unit>
+      <trans-unit id="The_folder_to_operate_on_Cannot_be_used_with_the_workspace_option">
+        <source>The folder to operate on. Cannot be used with the `--workspace` option.</source>
+        <target state="new">The folder to operate on. Cannot be used with the `--workspace` option.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="The_project_file_0_does_not_exist">
         <source>The project file '{0}' does not exist.</source>
         <target state="translated">Proje dosyası '{0}' yok.</target>
diff --git a/src/xlf/Resources.zh-Hans.xlf b/src/xlf/Resources.zh-Hans.xlf
index 4f19172e6e..c978ddb51c 100644
--- a/src/xlf/Resources.zh-Hans.xlf
+++ b/src/xlf/Resources.zh-Hans.xlf
@@ -17,6 +17,11 @@
         <target state="translated">在“{0}”中同时找到 MSBuild 项目文件和解决方案文件。请指定要将哪一个文件用于 --workspace 选项。</target>
         <note />
       </trans-unit>
+      <trans-unit id="Cannot_specify_both_folder_and_workspace_options">
+        <source>Cannot specify both folder and workspace options.</source>
+        <target state="new">Cannot specify both folder and workspace options.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Complete_in_0_ms">
         <source>Complete in {0}ms.</source>
         <target state="new">Complete in {0}ms.</target>
@@ -122,6 +127,11 @@
         <target state="translated">文件“{0}”似乎不是有效的项目或解决方案文件。</target>
         <note />
       </trans-unit>
+      <trans-unit id="The_folder_to_operate_on_Cannot_be_used_with_the_workspace_option">
+        <source>The folder to operate on. Cannot be used with the `--workspace` option.</source>
+        <target state="new">The folder to operate on. Cannot be used with the `--workspace` option.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="The_project_file_0_does_not_exist">
         <source>The project file '{0}' does not exist.</source>
         <target state="translated">项目文件“{0}” 不存在。</target>
diff --git a/src/xlf/Resources.zh-Hant.xlf b/src/xlf/Resources.zh-Hant.xlf
index 5f60ebdcc6..05476acc16 100644
--- a/src/xlf/Resources.zh-Hant.xlf
+++ b/src/xlf/Resources.zh-Hant.xlf
@@ -17,6 +17,11 @@
         <target state="translated">在 '{0}' 中同時找到 MSBuild 專案檔和解決方案檔。請指定要搭配 --workspace 選項使用的檔案。</target>
         <note />
       </trans-unit>
+      <trans-unit id="Cannot_specify_both_folder_and_workspace_options">
+        <source>Cannot specify both folder and workspace options.</source>
+        <target state="new">Cannot specify both folder and workspace options.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Complete_in_0_ms">
         <source>Complete in {0}ms.</source>
         <target state="new">Complete in {0}ms.</target>
@@ -122,6 +127,11 @@
         <target state="translated">檔案 '{0}' 似乎不是有效的專案或解決方案檔。</target>
         <note />
       </trans-unit>
+      <trans-unit id="The_folder_to_operate_on_Cannot_be_used_with_the_workspace_option">
+        <source>The folder to operate on. Cannot be used with the `--workspace` option.</source>
+        <target state="new">The folder to operate on. Cannot be used with the `--workspace` option.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="The_project_file_0_does_not_exist">
         <source>The project file '{0}' does not exist.</source>
         <target state="translated">專案檔 '{0}' 不存在。</target>
diff --git a/tests/CodeFormatterTests.cs b/tests/CodeFormatterTests.cs
index cb4b32962f..fc61b20614 100644
--- a/tests/CodeFormatterTests.cs
+++ b/tests/CodeFormatterTests.cs
@@ -83,6 +83,31 @@ await TestFormatWorkspaceAsync(
                 expectedFileCount: 5);
         }
 
+
+        [Fact]
+        public async Task FilesFormattedInUnformattedProjectFolder()
+        {
+            // Since the code files are beneath the project folder, files are found and formatted.
+            await TestFormatWorkspaceAsync(
+                Path.GetDirectoryName(UnformattedProjectFilePath),
+                EmptyFilesToFormat,
+                expectedExitCode: 0,
+                expectedFilesFormatted: 2,
+                expectedFileCount: 3);
+        }
+
+        [Fact]
+        public async Task NoFilesFormattedInUnformattedSolutionFolder()
+        {
+            // Since the code files are outside the solution folder, no files are found or formatted.
+            await TestFormatWorkspaceAsync(
+                Path.GetDirectoryName(UnformattedSolutionFilePath),
+                EmptyFilesToFormat,
+                expectedExitCode: 0,
+                expectedFilesFormatted: 0,
+                expectedFileCount: 0);
+        }
+
         [Fact]
         public async Task FSharpProjectsDoNotCreateException()
         {
@@ -210,16 +235,28 @@ public async Task FormatLocationsNotLoggedInFormattedProject()
             Assert.Empty(formatLocations);
         }
 
-        public async Task<string> TestFormatWorkspaceAsync(string solutionOrProjectPath, IEnumerable<string> files, int expectedExitCode, int expectedFilesFormatted, int expectedFileCount)
+        public async Task<string> TestFormatWorkspaceAsync(string workspaceFilePath, IEnumerable<string> files, int expectedExitCode, int expectedFilesFormatted, int expectedFileCount)
         {
-            var workspacePath = Path.GetFullPath(solutionOrProjectPath);
-            var isSolution = workspacePath.EndsWith(".sln");
+            var workspacePath = Path.GetFullPath(workspaceFilePath);
+
+            WorkspaceType workspaceType;
+            if (Directory.Exists(workspacePath))
+            {
+                workspaceType = WorkspaceType.Folder;
+            }
+            else
+            {
+                workspaceType = workspacePath.EndsWith(".sln")
+                    ? WorkspaceType.Solution
+                    : WorkspaceType.Project;
+            }
+
             var filesToFormat = files.Select(Path.GetFullPath).ToImmutableHashSet(StringComparer.OrdinalIgnoreCase);
 
             var logger = new TestLogger();
             var formatOptions = new FormatOptions(
                 workspacePath,
-                isSolution,
+                workspaceType,
                 LogLevel.Trace,
                 saveFormattedFiles: false,
                 changesAreErrors: false,
diff --git a/tests/Formatters/AbstractFormatterTests.cs b/tests/Formatters/AbstractFormatterTests.cs
index 00c9c0ff2c..436aa720ce 100644
--- a/tests/Formatters/AbstractFormatterTests.cs
+++ b/tests/Formatters/AbstractFormatterTests.cs
@@ -87,7 +87,7 @@ private protected async Task<SourceText> TestAsync(string testCode, string expec
             var document = project.Documents.Single();
             var formatOptions = new FormatOptions(
                 workspaceFilePath: project.FilePath,
-                isSolution: false,
+                workspaceType: WorkspaceType.Folder,
                 logLevel: LogLevel.Trace,
                 saveFormattedFiles: false,
                 changesAreErrors: false,
diff --git a/tests/ProgramTests.cs b/tests/ProgramTests.cs
index 6ba32f6867..2eb7ea2495 100644
--- a/tests/ProgramTests.cs
+++ b/tests/ProgramTests.cs
@@ -38,10 +38,10 @@ public void ExitCodeIsSameWithoutCheck()
         public void FilesFormattedDirectorySeparatorInsensitive()
         {
             var filePath = $"other_items{Path.DirectorySeparatorChar}OtherClass.cs";
-            var files = Program.GetFilesToFormat(filePath);
+            var files = Program.GetFilesToFormat(filePath, folder: null);
 
             var filePathAlt = $"other_items{Path.AltDirectorySeparatorChar}OtherClass.cs";
-            var filesAlt = Program.GetFilesToFormat(filePathAlt);
+            var filesAlt = Program.GetFilesToFormat(filePathAlt, folder: null);
 
             Assert.True(files.IsSubsetOf(filesAlt));
         }