Refactor the logic of S4663

SonarSource · Jan 26, 2023 · beb705c · beb705c
1 parent c1cf2c4
commit beb705c
Show file tree

Hide file tree

Showing 3 changed files with 94 additions and 15 deletions.
diff --git a/analyzers/src/SonarAnalyzer.CSharp/Rules/CommentsShouldNotBeEmpty.cs b/analyzers/src/SonarAnalyzer.CSharp/Rules/CommentsShouldNotBeEmpty.cs
@@ -27,6 +27,13 @@ public sealed class CommentsShouldNotBeEmpty : CommentsShouldNotBeEmptyBase<Synt
 {
     protected override ILanguageFacade<SyntaxKind> Language => CSharpFacade.Instance;
 
+    protected override bool IsValidTriviaType(SyntaxTrivia trivia)
+        => Language.SyntaxKind.CommentTrivia.Contains(trivia.Kind());
+
+    protected override bool IsSimpleComment(SyntaxTrivia trivia) => trivia.IsKind(SyntaxKind.SingleLineCommentTrivia);
+    protected override bool IsEndOfLine(SyntaxTrivia trivia) => trivia.IsKind(SyntaxKind.EndOfLineTrivia);
+    protected override bool IsWhitespace(SyntaxTrivia trivia) => trivia.IsKind(SyntaxKind.WhitespaceTrivia);
+
     protected override string GetCommentText(SyntaxTrivia trivia)
         => trivia.Kind() switch
         {
@@ -36,17 +43,10 @@ protected override string GetCommentText(SyntaxTrivia trivia)
             SyntaxKind.MultiLineDocumentationCommentTrivia => GetMultiLineDocumentationText(trivia),
         };
 
-    protected override bool IsValidTriviaType(SyntaxTrivia trivia)
-        => Language.SyntaxKind.CommentTrivia.Contains(trivia.Kind());
-
     // //
     private static string GetSingleLineText(SyntaxTrivia trivia)
         => trivia.ToString().Trim().Substring(2);
 
-    // /* */
-    private static string GetMultiLineText(SyntaxTrivia trivia) =>
-        ParseMultiLine(trivia.ToString(), 2); // Length of "/*"
-
     // ///
     private static string GetSingleLineDocumentationText(SyntaxTrivia trivia)
     {
@@ -64,6 +64,10 @@ private static string GetSingleLineDocumentationText(SyntaxTrivia trivia)
         return stringBuilder.ToString();
     }
 
+    // /* */
+    private static string GetMultiLineText(SyntaxTrivia trivia) =>
+        ParseMultiLine(trivia.ToString(), 2); // Length of "/*"
+
     // /** */
     private static string GetMultiLineDocumentationText(SyntaxTrivia trivia) =>
         ParseMultiLine(trivia.ToFullString(), 3); // Length of "/**"

diff --git a/analyzers/src/SonarAnalyzer.Common/Rules/CommentsShouldNotBeEmptyBase.cs b/analyzers/src/SonarAnalyzer.Common/Rules/CommentsShouldNotBeEmptyBase.cs
@@ -18,15 +18,21 @@
  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  */
 
+using Microsoft.CodeAnalysis.Text;
+
 namespace SonarAnalyzer.Rules;
 
 public abstract class CommentsShouldNotBeEmptyBase<TSyntaxKind> : SonarDiagnosticAnalyzer<TSyntaxKind>
     where TSyntaxKind : struct
 {
     private const string DiagnosticId = "S4663";
 
-    protected abstract bool IsValidTriviaType(SyntaxTrivia trivia);
     protected abstract string GetCommentText(SyntaxTrivia trivia);
+    protected abstract bool IsValidTriviaType(SyntaxTrivia trivia);
+
+    protected abstract bool IsSimpleComment(SyntaxTrivia trivia);
+    protected abstract bool IsEndOfLine(SyntaxTrivia trivia);
+    protected abstract bool IsWhitespace(SyntaxTrivia trivia);
 
     protected override string MessageFormat => "Remove this empty comment";
 
@@ -44,12 +50,77 @@ public abstract class CommentsShouldNotBeEmptyBase<TSyntaxKind> : SonarDiagnosti
 
     protected void CheckTrivia(SonarSyntaxTreeReportingContext context, IEnumerable<SyntaxTrivia> trivia)
     {
-        foreach (var trivium in trivia.Where(ShouldReport))
+        foreach (var partition in Partition(trivia).Where(ShouldReport))
+        {
+            var start = partition.First().GetLocation().SourceSpan.Start;
+            var end = partition.Last().GetLocation().SourceSpan.End;
+
+            var location = Location.Create(context.Tree, TextSpan.FromBounds(start, end));
+            context.ReportIssue(Diagnostic.Create(Rule, location));
+        }
+    }
+
+    protected IEnumerable<IEnumerable<SyntaxTrivia>> Partition(IEnumerable<SyntaxTrivia> trivia)
+    {
+        var res = new List<List<SyntaxTrivia>>();
+
+        var current = new List<SyntaxTrivia>();
+        var endOfLineFound = false;
+
+        foreach (var trivium in trivia)
         {
-            context.ReportIssue(Diagnostic.Create(Rule, trivium.GetLocation()));
+            if (IsWhitespace(trivium))
+            {
+                continue;
+            }
+
+            if (IsSimpleComment(trivium)) // put it on the current block of "//"
+            {
+                current.Add(trivium);
+                endOfLineFound = false;
+                continue;
+            }
+
+            // This is for the case, of two different comment types, for example:
+            // //
+            // ///
+            if (IsValidTriviaType(trivium)) // valid but not "//", because of the upper if
+            {
+                AddCurrent();
+                res.Add(new List<SyntaxTrivia> { trivium });
+            }
+            else if (IsEndOfLine(trivium))
+            {
+                // This is for the case, of an empty line in between, for example:
+                // //
+                //
+                // //
+                if (endOfLineFound)
+                {
+                    AddCurrent();
+                }
+                else
+                {
+                    endOfLineFound = true;
+                }
+            }
+            else
+            {
+                AddCurrent();
+            }
         }
 
-        bool ShouldReport(SyntaxTrivia trivia)
-        => IsValidTriviaType(trivia) && string.IsNullOrEmpty(GetCommentText(trivia));
+        res.Add(current);
+        return res;
+
+        void AddCurrent()
+        {
+            res.Add(current);
+            current = new();
+            endOfLineFound = false;
+        }
     }
+
+    protected bool ShouldReport(IEnumerable<SyntaxTrivia> trivia) =>
+        trivia.Any() && trivia.All(x => GetCommentText(x) == string.Empty);
 }
diff --git a/analyzers/src/SonarAnalyzer.VisualBasic/Rules/CommentsShouldNotBeEmpty.cs b/analyzers/src/SonarAnalyzer.VisualBasic/Rules/CommentsShouldNotBeEmpty.cs
@@ -27,16 +27,20 @@ public sealed class CommentsShouldNotBeEmpty : CommentsShouldNotBeEmptyBase<Synt
 {
     protected override ILanguageFacade<SyntaxKind> Language => VisualBasicFacade.Instance;
 
+    protected override bool IsValidTriviaType(SyntaxTrivia trivia)
+        => Language.SyntaxKind.CommentTrivia.Contains(trivia.Kind());
+
+    protected override bool IsSimpleComment(SyntaxTrivia trivia) => trivia.IsKind(SyntaxKind.CommentTrivia);
+    protected override bool IsEndOfLine(SyntaxTrivia trivia) => trivia.IsKind(SyntaxKind.EndOfLineTrivia);
+    protected override bool IsWhitespace(SyntaxTrivia trivia) => trivia.IsKind(SyntaxKind.WhitespaceTrivia);
+
     protected override string GetCommentText(SyntaxTrivia trivia)
         => trivia.Kind() switch
         {
             SyntaxKind.CommentTrivia => GetText(trivia),
             SyntaxKind.DocumentationCommentTrivia => GetDocumentationText(trivia),
         };
 
-    protected override bool IsValidTriviaType(SyntaxTrivia trivia)
-        => Language.SyntaxKind.CommentTrivia.Contains(trivia.Kind());
-
     // '
     private static string GetText(SyntaxTrivia trivia)
         => trivia.ToString().Trim().Substring(1);