Consolidate file-level directive manipulation

src/Cli/Microsoft.DotNet.FileBasedPrograms/FileLevelDirectiveHelpers.cs

@@ -77,7 +77,6 @@ void ReportErrorFor(SyntaxTrivia trivia)
             }
         }
 
-        // The result should be ordered by source location, RemoveDirectivesFromFile depends on that.
         return builder.ToImmutable();
     }
 
@@ -112,7 +111,7 @@ public static void FindLeadingDirectives(
             {
                 TextSpan span = GetFullSpan(previousWhiteSpaceSpan, trivia);
 
-                var whiteSpace = GetWhiteSpaceInfo(triviaList, index);
+                var whiteSpace = GetWhiteSpaceInfo(triviaList, index, span);
                 var info = new CSharpDirective.ParseInfo
                 {
                     SourceFile = sourceFile,
@@ -134,7 +133,7 @@ public static void FindLeadingDirectives(
                 var value = parts.Length > 1 ? parts[1] : "";
                 Debug.Assert(!(parts.Length > 2));
 
-                var whiteSpace = GetWhiteSpaceInfo(triviaList, index);
+                var whiteSpace = GetWhiteSpaceInfo(triviaList, index, span);
                 var context = new CSharpDirective.ParseContext
                 {
                     Info = new()
@@ -183,35 +182,42 @@ static TextSpan GetFullSpan(TextSpan previousWhiteSpaceSpan, SyntaxTrivia trivia
             return previousWhiteSpaceSpan.IsEmpty ? trivia.FullSpan : TextSpan.FromBounds(previousWhiteSpaceSpan.Start, trivia.FullSpan.End);
         }
 
-        static (WhiteSpaceInfo Leading, WhiteSpaceInfo Trailing) GetWhiteSpaceInfo(in SyntaxTriviaList triviaList, int index)
+        static (WhiteSpaceInfo Leading, WhiteSpaceInfo Trailing) GetWhiteSpaceInfo(in SyntaxTriviaList triviaList, int index, TextSpan excludeSpan)
         {
             (WhiteSpaceInfo Leading, WhiteSpaceInfo Trailing) result = default;
 
             for (int i = index - 1; i >= 0; i--)
             {
-                if (!Fill(ref result.Leading, triviaList, i)) break;
+                if (!Fill(ref result.Leading, triviaList, i, excludeSpan)) break;
             }
 
             for (int i = index + 1; i < triviaList.Count; i++)
             {
-                if (!Fill(ref result.Trailing, triviaList, i)) break;
+                if (!Fill(ref result.Trailing, triviaList, i, excludeSpan)) break;
             }
 
             return result;
 
-            static bool Fill(ref WhiteSpaceInfo info, in SyntaxTriviaList triviaList, int index)
+            static bool Fill(ref WhiteSpaceInfo info, in SyntaxTriviaList triviaList, int index, TextSpan excludeSpan)
             {
                 var trivia = triviaList[index];
+
+                var length = trivia.FullSpan.Length - (trivia.FullSpan.Intersection(excludeSpan)?.Length ?? 0);
+
                 if (trivia.IsKind(SyntaxKind.EndOfLineTrivia))
                 {
-                    info.LineBreaks += 1;
-                    info.TotalLength += trivia.FullSpan.Length;
+                    if (length != 0)
+                    {
+                        info.BlankLineLength += info.RestLength + length;
+                        info.RestLength = 0;
+                    }
+
                     return true;
                 }
 
                 if (trivia.IsKind(SyntaxKind.WhitespaceTrivia))
                 {
-                    info.TotalLength += trivia.FullSpan.Length;
+                    info.RestLength += length;
                     return true;
                 }
 
@@ -272,8 +278,15 @@ internal static partial class Patterns
 
 internal struct WhiteSpaceInfo
 {
-    public int LineBreaks;
-    public int TotalLength;
+    /// <summary>
+    /// Size of whitespace that consists of only blank lines (i.e., lines that contain only whitespace).
+    /// </summary>
+    public int BlankLineLength;
+
+    /// <summary>
+    /// Size of the remaining whitespace on a not-entirely-blank line.
+    /// </summary>
+    public int RestLength;
 }
 
 /// <summary>
@@ -287,11 +300,20 @@ internal abstract class CSharpDirective(in CSharpDirective.ParseInfo info)
     public readonly struct ParseInfo
     {
         public required SourceFile SourceFile { get; init; }
+
         /// <summary>
         /// Span of the full line including the trailing line break.
         /// </summary>
         public required TextSpan Span { get; init; }
+
+        /// <summary>
+        /// Additional leading whitespace not included in <see cref="Span"/>.
+        /// </summary>
         public required WhiteSpaceInfo LeadingWhiteSpace { get; init; }
+
+        /// <summary>
+        /// Additional trailing whitespace not included in <see cref="Span"/>.
+        /// </summary>
         public required WhiteSpaceInfo TrailingWhiteSpace { get; init; }
     }
 

src/Cli/Microsoft.DotNet.FileBasedPrograms/InternalAPI.Unshipped.txt

@@ -115,8 +115,8 @@ Microsoft.DotNet.FileBasedPrograms.SourceFile.Text.init -> void
 Microsoft.DotNet.FileBasedPrograms.SourceFile.WithPath(string! newPath) -> Microsoft.DotNet.FileBasedPrograms.SourceFile
 Microsoft.DotNet.FileBasedPrograms.SourceFile.WithText(Microsoft.CodeAnalysis.Text.SourceText! newText) -> Microsoft.DotNet.FileBasedPrograms.SourceFile
 Microsoft.DotNet.FileBasedPrograms.WhiteSpaceInfo
-Microsoft.DotNet.FileBasedPrograms.WhiteSpaceInfo.LineBreaks -> int
-Microsoft.DotNet.FileBasedPrograms.WhiteSpaceInfo.TotalLength -> int
+Microsoft.DotNet.FileBasedPrograms.WhiteSpaceInfo.BlankLineLength -> int
+Microsoft.DotNet.FileBasedPrograms.WhiteSpaceInfo.RestLength -> int
 Microsoft.DotNet.FileBasedPrograms.WhiteSpaceInfo.WhiteSpaceInfo() -> void
 Microsoft.DotNet.ProjectTools.ProjectLocator
 override abstract Microsoft.DotNet.FileBasedPrograms.CSharpDirective.ToString() -> string!

src/Cli/dotnet/Commands/Project/Convert/ProjectConvertCommand.cs

@@ -67,7 +67,7 @@ public override int Execute()
         }
         else
         {
-            VirtualProjectBuilder.RemoveDirectivesFromFile(evaluatedDirectives, builder.EntryPointSourceFile, targetFile);
+            VirtualProjectBuildingCommand.RemoveDirectivesFromFile(builder.EntryPointSourceFile, targetFile);
         }
 
         // Create project file.
@@ -112,7 +112,7 @@ public override int Execute()
                 else
                 {
                     var sourceFile = SourceFile.Load(item.FullPath);
-                    VirtualProjectBuilder.RemoveDirectivesFromFile(evaluatedDirectives, sourceFile, targetItemFullPath);
+                    VirtualProjectBuildingCommand.RemoveDirectivesFromFile(sourceFile, targetItemFullPath);
                 }
             }
             else

src/Cli/dotnet/Commands/Run/FileBasedAppSourceEditor.cs

@@ -230,27 +230,37 @@ public void Remove(CSharpDirective directive)
     {
         var span = directive.Info.Span;
         var start = span.Start;
-        var length = span.Length + DetermineTrailingLengthToRemove(directive);
+        var length = span.Length;
+
+        DetermineWhiteSpaceToRemove(directive, out int leadingLength, out int trailingLength);
+        start -= leadingLength;
+        length += trailingLength;
+
         SourceFile = SourceFile.WithText(SourceFile.Text.Replace(start: start, length: length, newText: string.Empty));
     }
 
-    private static int DetermineTrailingLengthToRemove(CSharpDirective directive)
+    private static void DetermineWhiteSpaceToRemove(CSharpDirective directive, out int leadingLength, out int trailingLength)
     {
-        // If there are blank lines both before and after the directive, remove the trailing white space.
-        if (directive.Info.LeadingWhiteSpace.LineBreaks > 0 && directive.Info.TrailingWhiteSpace.LineBreaks > 0)
+        // If there are blank lines both before and after the directive, remove the trailing blank lines.
+        if (directive.Info.LeadingWhiteSpace.BlankLineLength > 0 && directive.Info.TrailingWhiteSpace.BlankLineLength > 0)
         {
-            return directive.Info.TrailingWhiteSpace.TotalLength;
+            leadingLength = 0;
+            trailingLength = directive.Info.TrailingWhiteSpace.BlankLineLength;
+            return;
         }
 
         // If the directive (including leading white space) starts at the beginning of the file,
-        // remove both the leading and trailing white space.
-        var startBeforeWhiteSpace = directive.Info.Span.Start - directive.Info.LeadingWhiteSpace.TotalLength;
+        // remove both the leading and trailing blank lines.
+        var startBeforeWhiteSpace = directive.Info.Span.Start - directive.Info.LeadingWhiteSpace.BlankLineLength;
         if (startBeforeWhiteSpace == 0)
         {
-            return directive.Info.LeadingWhiteSpace.TotalLength + directive.Info.TrailingWhiteSpace.TotalLength;
+            leadingLength = directive.Info.LeadingWhiteSpace.BlankLineLength;
+            trailingLength = directive.Info.TrailingWhiteSpace.BlankLineLength;
+            return;
         }
 
         Debug.Assert(startBeforeWhiteSpace > 0);
-        return 0;
+        leadingLength = 0;
+        trailingLength = 0;
     }
 }

src/Cli/dotnet/Commands/Run/VirtualProjectBuildingCommand.cs

@@ -1178,6 +1178,24 @@ public static void CreateTempSubdirectory(string path)
         static (sourceFile, textSpan, message, innerException) => throw new GracefulException(
             $"{sourceFile.GetLocationString(textSpan)}: {FileBasedProgramsResources.DirectiveError}: {message}",
             innerException);
+
+    public static SourceFile RemoveDirectivesFromFile(SourceFile sourceFile)
+    {
+        var editor = FileBasedAppSourceEditor.Load(sourceFile);
+
+        while (editor.Directives is [{ } directive, ..])
+        {
+            editor.Remove(directive);
+        }
+
+        return editor.SourceFile;
+    }
+
+    public static void RemoveDirectivesFromFile(SourceFile sourceFile, string targetFilePath)
+    {
+        var modifiedFile = RemoveDirectivesFromFile(sourceFile);
+        modifiedFile.WithPath(targetFilePath).Save();
+    }
 }
 
 internal sealed class RunFileBuildCacheEntry

src/Microsoft.DotNet.ProjectTools/VirtualProjectBuilder.cs

@@ -753,38 +753,4 @@ static void WriteImport(TextWriter writer, string project, CSharpDirective.Sdk s
             }
         }
     }
-
-    public static SourceFile RemoveDirectivesFromFile(ImmutableArray<CSharpDirective> directives, SourceFile sourceFile)
-    {
-        if (directives.Length == 0)
-        {
-            return sourceFile;
-        }
-
-#if DEBUG
-        var filteredDirectives = directives.Where(d => d.Info.SourceFile.Path == sourceFile.Path);
-        Debug.Assert(
-            filteredDirectives.OrderBy(static d => d.Info.Span.Start).SequenceEqual(filteredDirectives),
-            "Directives should be ordered by source location.");
-#endif
-
-        var text = sourceFile.Text;
-
-        for (int i = directives.Length - 1; i >= 0; i--)
-        {
-            var directive = directives[i];
-            if (directive.Info.SourceFile.Path == sourceFile.Path)
-            {
-                text = text.Replace(directive.Info.Span, string.Empty);
-            }
-        }
-
-        return sourceFile.WithText(text);
-    }
-
-    public static void RemoveDirectivesFromFile(ImmutableArray<CSharpDirective> directives, SourceFile sourceFile, string targetFilePath)
-    {
-        var modifiedFile = RemoveDirectivesFromFile(directives, sourceFile);
-        modifiedFile.WithPath(targetFilePath).Save();
-    }
 }

test/dotnet.Tests/CommandTests/Project/Convert/DotnetProjectConvertTests.cs

@@ -1645,7 +1645,6 @@ public void Directives_BlankLines()
                 """,
             expectedProject: expectedProject,
             expectedCSharp: """
-
                 Console.WriteLine();
                 """);
 
@@ -1968,7 +1967,7 @@ private static void Convert(
 
         actualProject = projectWriter.ToString();
 
-        var convertedFile = VirtualProjectBuilder.RemoveDirectivesFromFile(directives, builder.EntryPointSourceFile);
+        var convertedFile = VirtualProjectBuildingCommand.RemoveDirectivesFromFile(builder.EntryPointSourceFile);
         actualCSharp = convertedFile.Text != builder.EntryPointSourceFile.Text ? convertedFile.Text.ToString() : null;
     }
 

test/dotnet.Tests/CommandTests/Run/FileBasedAppSourceEditorTests.cs

@@ -109,6 +109,51 @@ public void PreExistingWhiteSpace()
             """));
     }
 
+    [Fact]
+    public void LeadingWhiteSpace()
+    {
+        Verify(
+            """
+
+            #:package MyPackage@1.0.0
+            Console.WriteLine();
+            """,
+            (static editor => editor.Remove(editor.Directives.Single()),
+            """
+
+            Console.WriteLine();
+            """));
+
+        Verify(
+            """
+              #:package MyPackage@1.0.0
+            Console.WriteLine();
+            """,
+            (static editor => editor.Remove(editor.Directives.Single()),
+            """
+            Console.WriteLine();
+            """));
+    }
+
+    [Fact]
+    public void WhiteSpaceOutsideLines()
+    {
+        Verify(
+            $"""
+            // trailing{"  "}
+
+            #:package MyPackage@1.0.0
+
+              // leading
+            """,
+            (static editor => editor.Remove(editor.Directives.Single()),
+            $"""
+            // trailing{"  "}
+
+              // leading
+            """));
+    }
+
     [Fact]
     public void Comments()
     {