Add analyzer RemoveEmptySyntax

ChangeLog.md

@@ -10,19 +10,28 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 - Add SECURITY.md ([#1147](https://github.com/josefpihrt/roslynator/pull/1147))
-- Add custom FixAllProvider for [RCS1014](https://github.com/JosefPihrt/Roslynator/blob/main/docs/analyzers/RCS1014.md) ([#1070](https://github.com/JosefPihrt/Roslynator/pull/1070)).
-- Add more cases to [RCS1097](https://github.com/JosefPihrt/Roslynator/blob/main/docs/analyzers/RCS1097.md) ([#1160](https://github.com/JosefPihrt/Roslynator/pull/1160)).
+- Add custom FixAllProvider for [RCS1014](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1014.md) ([#1070](https://github.com/JosefPihrt/Roslynator/pull/1070)).
+- Add more cases to [RCS1097](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1097.md) ([#1160](https://github.com/JosefPihrt/Roslynator/pull/1160)).
 - Add analyzer "Use enum field explicitly" ([RCS1257](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1257)) ([#889](https://github.com/josefpihrt/roslynator/pull/889)).
   - Enabled by default.
-- Add analyzer "Unnecessary enum flag" [RCS1258](https://github.com/JosefPihrt/Roslynator/blob/main/docs/analyzers/RCS1258.md) ([#886](https://github.com/JosefPihrt/Roslynator/pull/886)).
+- Add analyzer "Unnecessary enum flag" [RCS1258](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1258.md) ([#886](https://github.com/JosefPihrt/Roslynator/pull/886)).
   - Enabled by default.
 - Make `Roslynator.Rename.SymbolRenamer` public ([#1161](https://github.com/josefpihrt/roslynator/pull/1161))
+- Analyzer 'Remove empty syntax' ([RCS1259](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1259.md)) ([#913](https://github.com/josefpihrt/roslynator/pull/913)).
+  - This analyzer replaces following analyzers:
+    - Remove empty empty statement ([RCS1038](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1038.md))
+    - Remove empty 'else' clause ([RCS1040](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1040.md))
+    - Remove empty object initializer ([RCS1041](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1041.md))
+    - Remove empty 'finally' clause ([RCS1066](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1066.md))
+    - Remove empty namespace declaration ([RCS1072](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1072.md))
+    - Remove empty region directive ([RCS1091](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1091.md))
+    - Remove empty destructor ([RCS1106](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1106.md))
 
 ### Fixed
 
-- Fix [RCS1187](https://github.com/JosefPihrt/Roslynator/blob/main/docs/analyzers/RCS1187.md) ([#1150](https://github.com/JosefPihrt/Roslynator/pull/1150)).
-- Fix [RCS1056](https://github.com/JosefPihrt/Roslynator/blob/main/docs/analyzers/RCS1056.md) ([#1154](https://github.com/JosefPihrt/Roslynator/pull/1154)).
-- Fix [RCS1208](https://github.com/JosefPihrt/Roslynator/blob/main/docs/analyzers/RCS1208.md) ([#1153](https://github.com/JosefPihrt/Roslynator/pull/1153))
+- Fix [RCS1187](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1187.md) ([#1150](https://github.com/JosefPihrt/Roslynator/pull/1150)).
+- Fix [RCS1056](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1056.md) ([#1154](https://github.com/JosefPihrt/Roslynator/pull/1154)).
+- Fix [RCS1208](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1208.md) ([#1153](https://github.com/JosefPihrt/Roslynator/pull/1153))
 
 ## [4.4.0] - 2023-08-01
 
@@ -51,13 +60,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fix [RCS1154](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1154) ([#1105](https://github.com/JosefPihrt/Roslynator/pull/1105)).
 - Fix [RCS1211](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1211) ([#1095](https://github.com/JosefPihrt/Roslynator/pull/1095)).
 - Fix [RCS0005](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS0005) ([#1114](https://github.com/JosefPihrt/Roslynator/pull/1114)).
-- Fix [RCS1176](https://github.com/JosefPihrt/Roslynator/blob/main/docs/analyzers/RCS1176.md) ([#1122](https://github.com/JosefPihrt/Roslynator/pull/1122), [#1140](https://github.com/JosefPihrt/Roslynator/pull/1140)).
-- Fix [RCS1085](https://github.com/JosefPihrt/Roslynator/blob/main/docs/analyzers/RCS1085.md) ([#1120](https://github.com/josefpihrt/roslynator/pull/1120)).
-- Fix [RCS1208](https://github.com/JosefPihrt/Roslynator/blob/main/docs/analyzers/RCS1208.md) ([#1119](https://github.com/JosefPihrt/Roslynator/pull/1119)).
+- Fix [RCS1176](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1176.md) ([#1122](https://github.com/JosefPihrt/Roslynator/pull/1122), [#1140](https://github.com/JosefPihrt/Roslynator/pull/1140)).
+- Fix [RCS1085](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1085.md) ([#1120](https://github.com/josefpihrt/roslynator/pull/1120)).
+- Fix [RCS1208](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1208.md) ([#1119](https://github.com/JosefPihrt/Roslynator/pull/1119)).
 - [CLI] Fix member full declaration in generated documentation (command `generate-doc`) ([#1130](https://github.com/josefpihrt/roslynator/pull/1130)).
   - Append `?` to nullable reference types.
-- Fix [RCS1179](https://github.com/JosefPihrt/Roslynator/blob/main/docs/analyzers/RCS1179.md) ([#1129](https://github.com/JosefPihrt/Roslynator/pull/1129)).
-- Fix [RCS0060](https://github.com/JosefPihrt/Roslynator/blob/main/docs/analyzers/RCS0060.md) ([#1139](https://github.com/JosefPihrt/Roslynator/pull/1139)).
+- Fix [RCS1179](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1179.md) ([#1129](https://github.com/JosefPihrt/Roslynator/pull/1129)).
+- Fix [RCS0060](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS0060.md) ([#1139](https://github.com/JosefPihrt/Roslynator/pull/1139)).
 
 ## [4.3.0] - 2023-04-24
 

src/Analyzers.CodeFixes/CSharp/CodeFixes/ElseClauseCodeFixProvider.cs

@@ -62,7 +62,7 @@ public override async Task RegisterCodeFixesAsync(CodeFixContext context)
         }
     }
 
-    private static async Task<Document> RemoveEmptyElseClauseAsync(
+    internal static async Task<Document> RemoveEmptyElseClauseAsync(
         Document document,
         ElseClauseSyntax elseClause,
         CancellationToken cancellationToken)

src/Analyzers.CodeFixes/CSharp/CodeFixes/FinallyClauseCodeFixProvider.cs

@@ -38,7 +38,7 @@ public override async Task RegisterCodeFixesAsync(CodeFixContext context)
         context.RegisterCodeFix(codeAction, context.Diagnostics[0]);
     }
 
-    private static async Task<Document> RemoveEmptyFinallyClauseAsync(
+    internal static async Task<Document> RemoveEmptyFinallyClauseAsync(
         Document document,
         FinallyClauseSyntax finallyClause,
         CancellationToken cancellationToken)

src/Analyzers.CodeFixes/CSharp/CodeFixes/RemoveEmptySyntaxCodeFixProvider.cs

@@ -0,0 +1,135 @@
+// Copyright (c) Josef Pihrt and Contributors. Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Composition;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CodeActions;
+using Microsoft.CodeAnalysis.CodeFixes;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Roslynator.CodeFixes;
+using Roslynator.CSharp.Refactorings;
+
+namespace Roslynator.CSharp.CodeFixes;
+
+[ExportCodeFixProvider(LanguageNames.CSharp, Name = nameof(RemoveEmptySyntaxCodeFixProvider))]
+[Shared]
+public sealed class RemoveEmptySyntaxCodeFixProvider : BaseCodeFixProvider
+{
+    public override ImmutableArray<string> FixableDiagnosticIds
+    {
+        get { return ImmutableArray.Create(DiagnosticIdentifiers.RemoveEmptySyntax); }
+    }
+
+    public override async Task RegisterCodeFixesAsync(CodeFixContext context)
+    {
+        SyntaxNode root = await context.GetSyntaxRootAsync().ConfigureAwait(false);
+
+        if (!TryFindFirstAncestorOrSelf(
+            root,
+            context.Span,
+            out SyntaxNode node,
+            findInsideTrivia: true,
+            predicate: f =>
+            {
+                switch (f.Kind())
+                {
+                    case SyntaxKind.DestructorDeclaration:
+                    case SyntaxKind.ElseClause:
+                    case SyntaxKind.EmptyStatement:
+                    case SyntaxKind.FinallyClause:
+                    case SyntaxKind.NamespaceDeclaration:
+                    case SyntaxKind.ObjectCreationExpression:
+                    case SyntaxKind.RegionDirectiveTrivia:
+                        return true;
+                    default:
+                        return false;
+                }
+            }))
+        {
+            return;
+        }
+
+        Document document = context.Document;
+        Diagnostic diagnostic = context.Diagnostics[0];
+
+        switch (node)
+        {
+            case DestructorDeclarationSyntax destructorDeclaration:
+                {
+                    CodeAction codeAction = CodeActionFactory.RemoveMemberDeclaration(
+                        document,
+                        destructorDeclaration,
+                        title: "Remove empty destructor",
+                        equivalenceKey: GetEquivalenceKey(diagnostic));
+
+                    context.RegisterCodeFix(codeAction, diagnostic);
+                    break;
+                }
+            case ElseClauseSyntax elseClause:
+                {
+                    CodeAction codeAction = CodeAction.Create(
+                        "Remove empty 'else' clause",
+                        ct => ElseClauseCodeFixProvider.RemoveEmptyElseClauseAsync(document, elseClause, ct),
+                        GetEquivalenceKey(diagnostic));
+
+                    context.RegisterCodeFix(codeAction, diagnostic);
+                    break;
+                }
+            case FinallyClauseSyntax finallyClause:
+                {
+                    CodeAction codeAction = CodeAction.Create(
+                        "Remove empty 'finally' clause",
+                        ct => FinallyClauseCodeFixProvider.RemoveEmptyFinallyClauseAsync(document, finallyClause, ct),
+                        equivalenceKey: GetEquivalenceKey(diagnostic));
+
+                    context.RegisterCodeFix(codeAction, diagnostic);
+                    break;
+                }
+            case ObjectCreationExpressionSyntax objectCreationExpression:
+                {
+                    CodeAction codeAction = CodeAction.Create(
+                        "Remove empty initializer",
+                        ct => RemoveEmptyInitializerRefactoring.RefactorAsync(document, objectCreationExpression, ct),
+                        GetEquivalenceKey(diagnostic));
+
+                    context.RegisterCodeFix(codeAction, diagnostic);
+                    break;
+                }
+            case NamespaceDeclarationSyntax namespaceDeclaration:
+                {
+                    CodeAction codeAction = CodeAction.Create(
+                        "Remove empty namespace declaration",
+                        ct => RemoveEmptyNamespaceDeclarationRefactoring.RefactorAsync(document, namespaceDeclaration, ct),
+                        GetEquivalenceKey(diagnostic));
+
+                    context.RegisterCodeFix(codeAction, diagnostic);
+                    break;
+                }
+            case RegionDirectiveTriviaSyntax regionDirective:
+                {
+                    CodeAction codeAction = CodeAction.Create(
+                        "Remove empty region",
+                        ct => RemoveEmptyRegionRefactoring.RefactorAsync(document, SyntaxInfo.RegionInfo(regionDirective), ct),
+                        GetEquivalenceKey(diagnostic));
+
+                    context.RegisterCodeFix(codeAction, diagnostic);
+                    break;
+                }
+            case EmptyStatementSyntax emptyStatement:
+                {
+                    CodeAction codeAction = CodeAction.Create(
+                        "Remove empty statement",
+                        ct => RemoveEmptyStatementRefactoring.RefactorAsync(document, emptyStatement, ct),
+                        GetEquivalenceKey(diagnostic));
+
+                    context.RegisterCodeFix(codeAction, diagnostic);
+                    break;
+                }
+        }
+    }
+}

src/Analyzers.xml

@@ -2435,10 +2435,13 @@ if (f)
   <Analyzer>
     <Id>RCS1038</Id>
     <Identifier>RemoveEmptyStatement</Identifier>
+    <Status>Obsolete</Status>
+    <ObsoleteMessage>Use RCS1259 instead</ObsoleteMessage>
     <Title>Remove empty statement.</Title>
     <DefaultSeverity>Info</DefaultSeverity>
-    <IsEnabledByDefault>true</IsEnabledByDefault>
+    <IsEnabledByDefault>false</IsEnabledByDefault>
     <SupportsFadeOut>true</SupportsFadeOut>
+    <Tags>HideFromConfiguration</Tags>
     <Samples>
       <Sample>
         <Before><![CDATA[public void Foo()
@@ -2474,10 +2477,13 @@ public void Foo()
   <Analyzer>
     <Id>RCS1040</Id>
     <Identifier>RemoveEmptyElseClause</Identifier>
+    <Status>Obsolete</Status>
+    <ObsoleteMessage>Use RCS1259 instead</ObsoleteMessage>
     <Title>Remove empty 'else' clause.</Title>
     <DefaultSeverity>Hidden</DefaultSeverity>
-    <IsEnabledByDefault>true</IsEnabledByDefault>
+    <IsEnabledByDefault>false</IsEnabledByDefault>
     <SupportsFadeOut>true</SupportsFadeOut>
+    <Tags>HideFromConfiguration</Tags>
     <Samples>
       <Sample>
         <Before><![CDATA[if (condition)
@@ -2497,10 +2503,13 @@ else
   <Analyzer>
     <Id>RCS1041</Id>
     <Identifier>RemoveEmptyInitializer</Identifier>
+    <Status>Obsolete</Status>
+    <ObsoleteMessage>Use RCS1259 instead</ObsoleteMessage>
     <Title>Remove empty initializer.</Title>
     <DefaultSeverity>Info</DefaultSeverity>
-    <IsEnabledByDefault>true</IsEnabledByDefault>
+    <IsEnabledByDefault>false</IsEnabledByDefault>
     <SupportsFadeOut>true</SupportsFadeOut>
+    <Tags>HideFromConfiguration</Tags>
     <Samples>
       <Sample>
         <Before><![CDATA[var items = new List<object>() { };]]></Before>
@@ -3093,11 +3102,14 @@ while (true);]]></Before>
   <Analyzer>
     <Id>RCS1066</Id>
     <Identifier>RemoveEmptyFinallyClause</Identifier>
+    <Status>Obsolete</Status>
+    <ObsoleteMessage>Use RCS1259 instead</ObsoleteMessage>
     <Title>Remove empty 'finally' clause.</Title>
     <DefaultSeverity>Hidden</DefaultSeverity>
-    <IsEnabledByDefault>true</IsEnabledByDefault>
+    <IsEnabledByDefault>false</IsEnabledByDefault>
     <SupportsFadeOut>true</SupportsFadeOut>
     <SupportsFadeOutAnalyzer>true</SupportsFadeOutAnalyzer>
+    <Tags>HideFromConfiguration</Tags>
     <Samples>
       <Sample>
         <Before><![CDATA[try
@@ -3248,10 +3260,13 @@ catch (Exception ex)
   <Analyzer>
     <Id>RCS1072</Id>
     <Identifier>RemoveEmptyNamespaceDeclaration</Identifier>
+    <Status>Obsolete</Status>
+    <ObsoleteMessage>Use RCS1259 instead</ObsoleteMessage>
     <Title>Remove empty namespace declaration.</Title>
     <DefaultSeverity>Info</DefaultSeverity>
-    <IsEnabledByDefault>true</IsEnabledByDefault>
+    <IsEnabledByDefault>false</IsEnabledByDefault>
     <SupportsFadeOut>true</SupportsFadeOut>
+    <Tags>HideFromConfiguration</Tags>
     <Samples>
       <Sample>
         <Before><![CDATA[namespace Foo
@@ -3675,10 +3690,13 @@ public string Foo
   <Analyzer>
     <Id>RCS1091</Id>
     <Identifier>RemoveEmptyRegion</Identifier>
+    <Status>Obsolete</Status>
+    <ObsoleteMessage>Use RCS1259 instead</ObsoleteMessage>
     <Title>Remove empty region.</Title>
     <DefaultSeverity>Hidden</DefaultSeverity>
-    <IsEnabledByDefault>true</IsEnabledByDefault>
+    <IsEnabledByDefault>false</IsEnabledByDefault>
     <SupportsFadeOutAnalyzer>true</SupportsFadeOutAnalyzer>
+    <Tags>HideFromConfiguration</Tags>
     <Samples>
       <Sample>
         <Before><![CDATA[#region Region
@@ -4006,10 +4024,13 @@ else
   <Analyzer>
     <Id>RCS1106</Id>
     <Identifier>RemoveEmptyDestructor</Identifier>
+    <Status>Obsolete</Status>
+    <ObsoleteMessage>Use RCS1259 instead</ObsoleteMessage>
     <Title>Remove empty destructor.</Title>
     <DefaultSeverity>Info</DefaultSeverity>
-    <IsEnabledByDefault>true</IsEnabledByDefault>
+    <IsEnabledByDefault>false</IsEnabledByDefault>
     <SupportsFadeOut>true</SupportsFadeOut>
+    <Tags>HideFromConfiguration</Tags>
     <Samples>
       <Sample>
         <Before><![CDATA[public class Foo
@@ -7382,6 +7403,23 @@ void M()
       </Sample>
     </Samples>
   </Analyzer>
+  <Analyzer Identifier="RemoveEmptySyntax">
+    <Id>RCS1259</Id>
+    <Title>Remove empty syntax.</Title>
+    <MessageFormat>Remove empty {0}.</MessageFormat>
+    <DefaultSeverity>Info</DefaultSeverity>
+    <IsEnabledByDefault>true</IsEnabledByDefault>
+    <SupportsFadeOut>true</SupportsFadeOut>
+    <Summary>This analyzer reports unnecessary syntax that can be safely removed such as:
+  * empty destructor
+  * empty 'else' clause
+  * empty empty statement
+  * empty 'finally' clause
+  * empty namespace declaration
+  * empty object initializer
+  * empty region directive
+</Summary>
+  </Analyzer>
   <Analyzer>
     <Id>RCS9001</Id>
     <Identifier>UsePatternMatching</Identifier>