dotnet · JoeRobich · Feb 26, 2021 · Feb 26, 2021 · Feb 26, 2021 · Feb 26, 2021
diff --git a/README.md b/README.md
@@ -101,6 +101,7 @@ Options:
   --fix-whitespace, -w                Run whitespace formatting. Run by default when not applying fixes.
   --fix-style, -s <severity>          Run code style analyzers and apply fixes.
   --fix-analyzers, -a <severity>      Run 3rd party analyzers and apply fixes.
+  --diagnostics <diagnostic ids>      A space separated list of diagnostic ids to use as a filter when fixing code style or 3rd party analyzers.
   --include <include>                 A list of relative file or folder paths to include in formatting. All files are formatted if empty.
   --exclude <exclude>                 A list of relative file or folder paths to exclude from formatting.
   --check                             Formats files without saving changes to disk. Terminates with a non-zero exit code if any files were formatted.
@@ -117,6 +118,7 @@ Add `format` after `dotnet` and before the command arguments that you want to ru
 | `dotnet format <workspace>`                                      | Formats a specific project or solution.                                                            |
 | `dotnet format <workspace> -f`                                   | Formats a particular folder and subfolders.                                                        |
 | `dotnet format <workspace> --fix-style warn`                     | Fixes only codestyle analyzer warnings.                                                            |
+| `dotnet format <workspace> --fix-style --diagnostics IDE0005`    | Fixes only codestyle analyzer errors for the IDE0005 diagnostic.                                   |
 | `dotnet format <workspace> --fix-whitespace --fix-style`         | Formats and fixes codestyle analyzer errors.                                                       |
 | `dotnet format <workspace> --fix-analyzers`                      | Fixes only 3rd party analyzer errors.                                                              |
 | `dotnet format <workspace> -wsa`                                 | Formats, fixes codestyle errors, and fixes 3rd party analyzer errors.                              |
@@ -143,8 +145,8 @@ You can build and package the tool using the following commands. The instruction
 ```console
 build -pack
 # The final line from the build will read something like
-# Successfully created package '..\artifacts\packages\Debug\Shipping\dotnet-format.6.0.0-dev.nupkg'.
-# Use the value that is in the form `6.0.0-dev` as the version in the next command.
+# Successfully created package '..\artifacts\packages\Debug\Shipping\dotnet-format.5.1.0-dev.nupkg'.
+# Use the value that is in the form `5.1.0-dev` as the version in the next command.
 dotnet tool install --add-source .\artifacts\packages\Debug\Shipping -g dotnet-format --version <version>
 dotnet format
 ```

diff --git a/docs/README.md b/docs/README.md
@@ -82,6 +82,20 @@ Running 3rd party analysis requires the use of a MSBuild solution or project fil
 
 - `--fix-analyzers <severity>` - Runs analysis and attempts to fix issues with severity equal or greater than specified. If no severity is specified then this defaults to error.
 
+#### Filter diagnostics to fix
+
+Typically when running codestyle or 3rd party analysis, all diagnostics of sufficient severity are reported and fixed. The `--diagnostics` option allows you to target a particular diagnostic or set of diagnostics of sufficient severity.
+
+- `--diagnostics <diagnostic ids>` - When used in conjunction with `--fix-style` or `--fix-analyzer`, allows you to apply targeted fixes for particular analyzers.
+
+*Example:*
+
+Run code-style analysis and fix unused using directive errors.
+
+```console
+dotnet-format ./format.sln --fix-style --diagnostics IDE0005
+```
+
 ### Filter files to format
 
 You can further narrow the list of files to be formatted by specifying a list of paths to include or exclude. When specifying folder paths the path must end with a directory separator. File globbing is supported.

diff --git a/perf/FormattedFiles.cs b/perf/FormattedFiles.cs
@@ -1,6 +1,7 @@
 // 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 BenchmarkDotNet.Attributes;
 using BenchmarkDotNet.Jobs;
 using Microsoft.CodeAnalysis.Tools.Utilities;
@@ -36,6 +37,7 @@ public void FilesFormattedFolder()
                 fixCategory: FixCategory.Whitespace,
                 codeStyleSeverity: DiagnosticSeverity.Error,
                 analyzerSeverity: DiagnosticSeverity.Error,
+                diagnostics: ImmutableHashSet<string>.Empty,
                 saveFormattedFiles: false,
                 changesAreErrors: false,
                 AllFileMatcher,
@@ -55,6 +57,7 @@ public void FilesFormattedProject()
                 fixCategory: FixCategory.Whitespace,
                 codeStyleSeverity: DiagnosticSeverity.Error,
                 analyzerSeverity: DiagnosticSeverity.Error,
+                diagnostics: ImmutableHashSet<string>.Empty,
                 saveFormattedFiles: false,
                 changesAreErrors: false,
                 AllFileMatcher,
@@ -74,6 +77,7 @@ public void FilesFormattedSolution()
                 fixCategory: FixCategory.Whitespace,
                 codeStyleSeverity: DiagnosticSeverity.Error,
                 analyzerSeverity: DiagnosticSeverity.Error,
+                diagnostics: ImmutableHashSet<string>.Empty,
                 saveFormattedFiles: false,
                 changesAreErrors: false,
                 AllFileMatcher,

diff --git a/perf/NoFilesFormatted.cs b/perf/NoFilesFormatted.cs
@@ -1,6 +1,7 @@
 // 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 BenchmarkDotNet.Attributes;
 using BenchmarkDotNet.Jobs;
 using Microsoft.CodeAnalysis.Tools.Utilities;
@@ -36,6 +37,7 @@ public void NoFilesFormattedFolder()
                 fixCategory: FixCategory.Whitespace,
                 codeStyleSeverity: DiagnosticSeverity.Error,
                 analyzerSeverity: DiagnosticSeverity.Error,
+                diagnostics: ImmutableHashSet<string>.Empty,
                 saveFormattedFiles: false,
                 changesAreErrors: false,
                 AllFileMatcher,
@@ -55,6 +57,7 @@ public void NoFilesFormattedProject()
                 fixCategory: FixCategory.Whitespace,
                 codeStyleSeverity: DiagnosticSeverity.Error,
                 analyzerSeverity: DiagnosticSeverity.Error,
+                diagnostics: ImmutableHashSet<string>.Empty,
                 saveFormattedFiles: false,
                 changesAreErrors: false,
                 AllFileMatcher,
@@ -74,6 +77,7 @@ public void NoFilesFormattedSolution()
                 fixCategory: FixCategory.Whitespace,
                 codeStyleSeverity: DiagnosticSeverity.Error,
                 analyzerSeverity: DiagnosticSeverity.Error,
+                diagnostics: ImmutableHashSet<string>.Empty,
                 saveFormattedFiles: false,
                 changesAreErrors: false,
                 AllFileMatcher,

diff --git a/perf/RealWorldSolution.cs b/perf/RealWorldSolution.cs
@@ -1,6 +1,7 @@
 // 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 BenchmarkDotNet.Attributes;
 using BenchmarkDotNet.Configs;
 using BenchmarkDotNet.Diagnosers;
@@ -38,6 +39,7 @@ public void FilesFormattedSolution()
                 fixCategory: FixCategory.Whitespace,
                 codeStyleSeverity: DiagnosticSeverity.Error,
                 analyzerSeverity: DiagnosticSeverity.Error,
+                diagnostics: ImmutableHashSet<string>.Empty,
                 saveFormattedFiles: false,
                 changesAreErrors: false,
                 AllFileMatcher,
@@ -57,6 +59,7 @@ public void FilesFormattedFolder()
                 fixCategory: FixCategory.Whitespace,
                 codeStyleSeverity: DiagnosticSeverity.Error,
                 analyzerSeverity: DiagnosticSeverity.Error,
+                diagnostics: ImmutableHashSet<string>.Empty,
                 saveFormattedFiles: false,
                 changesAreErrors: false,
                 AllFileMatcher,

diff --git a/src/Analyzers/AnalyzerFormatter.cs b/src/Analyzers/AnalyzerFormatter.cs
@@ -72,6 +72,12 @@ internal class AnalyzerFormatter : ICodeFormatter
                 .SelectMany(codefix => codefix.FixableDiagnosticIds.Where(id => id.StartsWith("CS") || id.StartsWith("BC")))
                 .ToImmutableHashSet();
 
+            // Filter compiler diagnostics
+            if (!fixableCompilerDiagnostics.IsEmpty && !formatOptions.Diagnostics.IsEmpty)
+            {
+                fixableCompilerDiagnostics.Intersect(formatOptions.Diagnostics);
+            }
+
             var analysisStopwatch = Stopwatch.StartNew();
             logger.LogTrace(Resources.Running_0_analysis, _name);
 
@@ -83,7 +89,7 @@ internal class AnalyzerFormatter : ICodeFormatter
             var severity = _informationProvider.GetSeverity(formatOptions);
 
             // Filter to analyzers that report diagnostics with equal or greater severity.
-            var projectAnalyzers = await FilterBySeverityAsync(solution, projectAnalyzersAndFixers, formattablePaths, severity, cancellationToken).ConfigureAwait(false);
+            var projectAnalyzers = await FilterAnalyzersAsync(solution, projectAnalyzersAndFixers, formattablePaths, severity, formatOptions.Diagnostics, cancellationToken).ConfigureAwait(false);
 
             // Determine which diagnostics are being reported for each project.
             var projectDiagnostics = await GetProjectDiagnosticsAsync(solution, projectAnalyzers, formattablePaths, formatOptions, severity, fixableCompilerDiagnostics, logger, formattedFiles, cancellationToken).ConfigureAwait(false);
@@ -248,11 +254,12 @@ static void LogDiagnosticLocations(Solution solution, IEnumerable<Diagnostic> di
             }
         }
 
-        internal static async Task<ImmutableDictionary<ProjectId, ImmutableArray<DiagnosticAnalyzer>>> FilterBySeverityAsync(
+        internal static async Task<ImmutableDictionary<ProjectId, ImmutableArray<DiagnosticAnalyzer>>> FilterAnalyzersAsync(
             Solution solution,
             ImmutableDictionary<ProjectId, AnalyzersAndFixers> projectAnalyzersAndFixers,
             ImmutableHashSet<string> formattablePaths,
             DiagnosticSeverity minimumSeverity,
+            ImmutableHashSet<string> diagnostics,
             CancellationToken cancellationToken)
         {
             // We only want to run analyzers for each project that have the potential for reporting a diagnostic with
@@ -273,6 +280,13 @@ static void LogDiagnosticLocations(Solution solution, IEnumerable<Diagnostic> di
                     .Where(analyzer => DoesAnalyzerSupportLanguage(analyzer, project.Language));
                 foreach (var analyzer in filteredAnalyzer)
                 {
+                    // Filter by diagnostics
+                    if (!diagnostics.IsEmpty &&
+                        !analyzer.SupportedDiagnostics.Any(descriptor => diagnostics.Contains(descriptor.Id)))
+                    {
+                        continue;
+                    }
+
                     // Always run naming style analyzers because we cannot determine potential severity.
                     // The reported diagnostics will be filtered by severity when they are run.
                     if (analyzer.GetType().FullName?.EndsWith("NamingStyleDiagnosticAnalyzer") == true)

diff --git a/src/FormatCommand.cs b/src/FormatCommand.cs
@@ -18,6 +18,7 @@ internal static class FormatCommand
             bool fixWhitespace,
             string? fixStyle,
             string? fixAnalyzers,
+            string[] diagnostics,
             string? verbosity,
             bool check,
             string[] include,
@@ -49,6 +50,10 @@ internal static RootCommand CreateCommandLineOptions()
                 {
                     Argument = new Argument<string?>("severity") { Arity = ArgumentArity.ZeroOrOne }.FromAmong(SeverityLevels)
                 },
+                new Option(new[] { "--diagnostics" }, Resources.A_space_separated_list_of_diagnostic_ids_to_use_as_a_filter_when_fixing_code_style_or_3rd_party_issues)
+                {
+                    Argument = new Argument<string[]>(() => Array.Empty<string>())
+                },
                 new Option(new[] { "--include" }, Resources.A_list_of_relative_file_or_folder_paths_to_include_in_formatting_All_files_are_formatted_if_empty)
                 {
                     Argument = new Argument<string[]>(() => Array.Empty<string>())
@@ -84,7 +89,7 @@ internal static RootCommand CreateCommandLineOptions()
             var folder = symbolResult.ValueForOption<bool>("--folder");
             var fixAnalyzers = symbolResult.OptionResult("--fix-analyzers");
             return folder && fixAnalyzers != null
-                ? "Cannot specify the '--folder' option when running analyzers."
+                ? Resources.Cannot_specify_the_folder_option_when_running_analyzers
                 : null;
         }
 
@@ -93,7 +98,7 @@ internal static RootCommand CreateCommandLineOptions()
             var folder = symbolResult.ValueForOption<bool>("--folder");
             var fixStyle = symbolResult.OptionResult("--fix-style");
             return folder && fixStyle != null
-                ? "Cannot specify the '--folder' option when fixing style."
+                ? Resources.Cannot_specify_the_folder_option_when_fixing_style
                 : null;
         }
 

diff --git a/src/FormatOptions.cs b/src/FormatOptions.cs
@@ -1,5 +1,6 @@
 // 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.CodeAnalysis.Tools.Utilities;
 using Microsoft.Extensions.Logging;
 
@@ -13,6 +14,7 @@ internal class FormatOptions
         public FixCategory FixCategory { get; }
         public DiagnosticSeverity CodeStyleSeverity { get; }
         public DiagnosticSeverity AnalyzerSeverity { get; }
+        public ImmutableHashSet<string> Diagnostics { get; }
         public bool SaveFormattedFiles { get; }
         public bool ChangesAreErrors { get; }
         public SourceFileMatcher FileMatcher { get; }
@@ -26,6 +28,7 @@ internal class FormatOptions
             FixCategory fixCategory,
             DiagnosticSeverity codeStyleSeverity,
             DiagnosticSeverity analyzerSeverity,
+            ImmutableHashSet<string> diagnostics,
             bool saveFormattedFiles,
             bool changesAreErrors,
             SourceFileMatcher fileMatcher,
@@ -38,6 +41,7 @@ internal class FormatOptions
             FixCategory = fixCategory;
             CodeStyleSeverity = codeStyleSeverity;
             AnalyzerSeverity = analyzerSeverity;
+            Diagnostics = diagnostics;
             SaveFormattedFiles = saveFormattedFiles;
             ChangesAreErrors = changesAreErrors;
             FileMatcher = fileMatcher;
@@ -52,6 +56,7 @@ internal class FormatOptions
             out FixCategory fixCategory,
             out DiagnosticSeverity codeStyleSeverity,
             out DiagnosticSeverity analyzerSeverity,
+            out ImmutableHashSet<string> diagnostics,
             out bool saveFormattedFiles,
             out bool changesAreErrors,
             out SourceFileMatcher fileMatcher,
@@ -64,6 +69,7 @@ internal class FormatOptions
             fixCategory = FixCategory;
             codeStyleSeverity = CodeStyleSeverity;
             analyzerSeverity = AnalyzerSeverity;
+            diagnostics = Diagnostics;
             saveFormattedFiles = SaveFormattedFiles;
             changesAreErrors = ChangesAreErrors;
             fileMatcher = FileMatcher;

diff --git a/src/Formatters/UnnecessaryImportsFormatter.cs b/src/Formatters/UnnecessaryImportsFormatter.cs
@@ -41,6 +41,13 @@ internal sealed class UnnecessaryImportsFormatter : DocumentFormatter
                 return sourceText;
             }
 
+            // If diagnostics are being filtered and IDE0005 isn't specified, then make no changes.
+            if (!formatOptions.Diagnostics.IsEmpty &&
+                !formatOptions.Diagnostics.Contains(IDE0005))
+            {
+                return sourceText;
+            }
+
             var tree = await document.GetSyntaxTreeAsync(cancellationToken).ConfigureAwait(false);
             if (tree is null)
             {

diff --git a/src/Program.cs b/src/Program.cs
@@ -1,6 +1,7 @@
 // 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.CommandLine;
 using System.CommandLine.Invocation;
 using System.CommandLine.Parsing;
@@ -47,6 +48,7 @@ private static async Task<int> Main(string[] args)
             bool fixWhitespace,
             string? fixStyle,
             string? fixAnalyzers,
+            string[] diagnostics,
             string? verbosity,
             bool check,
             string[] include,
@@ -148,6 +150,11 @@ private static async Task<int> Main(string[] args)
                     fixType |= FixCategory.Analyzers;
                 }
 
+                if (fixType == FixCategory.None && diagnostics.Length > 0)
+                {
+                    logger.LogWarning(Resources.The_diagnostics_option_only_applies_when_fixing_style_or_running_analyzers);
+                }
+
                 if (fixType == FixCategory.None || fixWhitespace)
                 {
                     fixType |= FixCategory.Whitespace;
@@ -164,6 +171,7 @@ private static async Task<int> Main(string[] args)
                     fixType,
                     codeStyleSeverity: GetSeverity(fixStyle ?? FixSeverity.Error),
                     analyzerSeverity: GetSeverity(fixAnalyzers ?? FixSeverity.Error),
+                    diagnostics: diagnostics.ToImmutableHashSet(),
                     saveFormattedFiles: !check,
                     changesAreErrors: check,
                     fileMatcher,

diff --git a/src/Resources.resx b/src/Resources.resx
@@ -297,4 +297,16 @@
   <data name="The_dotnet_format_version_is_0" xml:space="preserve">
     <value>The dotnet format version is '{0}'.</value>
   </data>
+  <data name="A_space_separated_list_of_diagnostic_ids_to_use_as_a_filter_when_fixing_code_style_or_3rd_party_issues" xml:space="preserve">
+    <value>A space separated list of diagnostic ids to use as a filter when fixing code style or 3rd party issues.</value>
+  </data>
+  <data name="The_diagnostics_option_only_applies_when_fixing_style_or_running_analyzers" xml:space="preserve">
+    <value>The '--diagnostics' option only applies when fixing style or running analyzers.</value>
+  </data>
+  <data name="Cannot_specify_the_folder_option_when_running_analyzers" xml:space="preserve">
+    <value>Cannot specify the '--folder' option when running analyzers.</value>
+  </data>
+  <data name="Cannot_specify_the_folder_option_when_fixing_style" xml:space="preserve">
+    <value>Cannot specify the '--folder' option when fixing style.</value>
+  </data>
 </root>