Merge pull request #42117 from CyrusNajmabadi/conflictMarkerFixAll

Add 'fix all' support for picking conflict-marker regions.

src/EditorFeatures/CSharpTest/ConflictMarkerResolution/ConflictMarkerResolutionTests.cs

@@ -8,6 +8,7 @@
 using Microsoft.CodeAnalysis.Diagnostics;
 using Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.Diagnostics;
 using Microsoft.CodeAnalysis.Test.Utilities;
+using Roslyn.Test.Utilities;
 using Xunit;
 
 namespace Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.ConflictMarkerResolution
@@ -448,6 +449,147 @@ static void Main2(string[] args)
         }
     }
 
+}", index: 2);
+        }
+
+        [WorkItem(21107, "https://github.com/dotnet/roslyn/issues/21107")]
+        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsResolveConflictMarker)]
+        public async Task TestFixAll1()
+        {
+            await TestInRegularAndScript1Async(
+@"
+using System;
+
+namespace N
+{
+{|FixAllInDocument:<<<<<<<|} This is mine!
+    class Program
+    {
+    }
+=======
+    class Program2
+    {
+    }
+>>>>>>> This is theirs!
+
+<<<<<<< This is mine!
+    class Program3
+    {
+    }
+=======
+    class Program4
+    {
+    }
+>>>>>>> This is theirs!
+}",
+@"
+using System;
+
+namespace N
+{
+    class Program
+    {
+    }
+
+    class Program3
+    {
+    }
+}", index: 0);
+        }
+
+        [WorkItem(21107, "https://github.com/dotnet/roslyn/issues/21107")]
+        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsResolveConflictMarker)]
+        public async Task TestFixAll2()
+        {
+            await TestInRegularAndScript1Async(
+@"
+using System;
+
+namespace N
+{
+{|FixAllInDocument:<<<<<<<|} This is mine!
+    class Program
+    {
+    }
+=======
+    class Program2
+    {
+    }
+>>>>>>> This is theirs!
+
+<<<<<<< This is mine!
+    class Program3
+    {
+    }
+=======
+    class Program4
+    {
+    }
+>>>>>>> This is theirs!
+}",
+@"
+using System;
+
+namespace N
+{
+    class Program2
+    {
+    }
+
+    class Program4
+    {
+    }
+}", index: 1);
+        }
+
+        [WorkItem(21107, "https://github.com/dotnet/roslyn/issues/21107")]
+        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsResolveConflictMarker)]
+        public async Task TestFixAll3()
+        {
+            await TestInRegularAndScript1Async(
+@"
+using System;
+
+namespace N
+{
+{|FixAllInDocument:<<<<<<<|} This is mine!
+    class Program
+    {
+    }
+=======
+    class Program2
+    {
+    }
+>>>>>>> This is theirs!
+
+<<<<<<< This is mine!
+    class Program3
+    {
+    }
+=======
+    class Program4
+    {
+    }
+>>>>>>> This is theirs!
+}",
+@"
+using System;
+
+namespace N
+{
+    class Program
+    {
+    }
+    class Program2
+    {
+    }
+
+    class Program3
+    {
+    }
+    class Program4
+    {
+    }
 }", index: 2);
         }
     }

src/EditorFeatures/VisualBasicTest/ConflictMarkerResolution/ConflictMarkerResolutionTests.vb

@@ -126,6 +126,118 @@ namespace N
             Console.WriteLine(""Their section"")
         end sub
     end class
+end namespace", index:=2)
+        End Function
+
+        <WorkItem(21107, "https://github.com/dotnet/roslyn/issues/21107")>
+        <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsResolveConflictMarker)>
+        Public Async Function TestFixAll1() As Task
+            Await TestInRegularAndScript1Async(
+"
+imports System
+
+namespace N
+{|FixAllInDocument:<<<<<<<|} This is mine!
+    class Program
+    end class
+=======
+    class Program2
+    end class
+>>>>>>> This is theirs!
+
+<<<<<<< This is mine!
+    class Program3
+    end class
+=======
+    class Program4
+    end class
+>>>>>>> This is theirs!
+end namespace",
+"
+imports System
+
+namespace N
+    class Program
+    end class
+
+    class Program3
+    end class
+end namespace", index:=0)
+        End Function
+
+        <WorkItem(21107, "https://github.com/dotnet/roslyn/issues/21107")>
+        <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsResolveConflictMarker)>
+        Public Async Function TestFixAll2() As Task
+            Await TestInRegularAndScript1Async(
+"
+imports System
+
+namespace N
+{|FixAllInDocument:<<<<<<<|} This is mine!
+    class Program
+    end class
+=======
+    class Program2
+    end class
+>>>>>>> This is theirs!
+
+<<<<<<< This is mine!
+    class Program3
+    end class
+=======
+    class Program4
+    end class
+>>>>>>> This is theirs!
+end namespace",
+"
+imports System
+
+namespace N
+    class Program2
+    end class
+
+    class Program4
+    end class
+end namespace", index:=1)
+        End Function
+
+        <WorkItem(21107, "https://github.com/dotnet/roslyn/issues/21107")>
+        <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsResolveConflictMarker)>
+        Public Async Function TestFixAll3() As Task
+            Await TestInRegularAndScript1Async(
+"
+imports System
+
+namespace N
+{|FixAllInDocument:<<<<<<<|} This is mine!
+    class Program
+    end class
+=======
+    class Program2
+    end class
+>>>>>>> This is theirs!
+
+<<<<<<< This is mine!
+    class Program3
+    end class
+=======
+    class Program4
+    end class
+>>>>>>> This is theirs!
+end namespace",
+"
+imports System
+
+namespace N
+    class Program
+    end class
+    class Program2
+    end class
+
+    class Program3
+    end class
+    class Program4
+    end class
 end namespace", index:=2)
         End Function
     End Class

src/Features/Core/Portable/ConflictMarkerResolution/AbstractConflictMarkerCodeFixProvider.cs

@@ -6,18 +6,25 @@
 
 using System;
 using System.Collections.Immutable;
+using System.Diagnostics;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis.CodeActions;
 using Microsoft.CodeAnalysis.CodeFixes;
 using Microsoft.CodeAnalysis.LanguageServices;
+using Microsoft.CodeAnalysis.PooledObjects;
 using Microsoft.CodeAnalysis.Shared.Extensions;
 using Microsoft.CodeAnalysis.Text;
+using Roslyn.Utilities;
 
 namespace Microsoft.CodeAnalysis.ConflictMarkerResolution
 {
-    internal abstract class AbstractResolveConflictMarkerCodeFixProvider : CodeFixProvider
+    internal abstract partial class AbstractResolveConflictMarkerCodeFixProvider : CodeFixProvider
     {
+        private const string TakeTopEquivalenceKey = nameof(TakeTopEquivalenceKey);
+        private const string TakeBottomEquivalenceKey = nameof(TakeBottomEquivalenceKey);
+        private const string TakeBothEquivalenceKey = nameof(TakeBothEquivalenceKey);
+
         private static readonly int s_mergeConflictLength = "<<<<<<<".Length;
 
         private readonly ISyntaxKinds _syntaxKinds;
@@ -29,15 +36,11 @@ internal abstract class AbstractResolveConflictMarkerCodeFixProvider : CodeFixPr
             _syntaxKinds = syntaxKinds;
         }
 
-        public override FixAllProvider? GetFixAllProvider()
-        {
-            // Fix All is not currently supported for this code fix
-            // https://github.com/dotnet/roslyn/issues/34461
-            return null;
-        }
-
         public override ImmutableArray<string> FixableDiagnosticIds { get; }
 
+        public override FixAllProvider GetFixAllProvider()
+            => new ConflictMarkerFixAllProvider(this);
+
         public override async Task RegisterCodeFixesAsync(CodeFixContext context)
         {
             var cancellationToken = context.CancellationToken;
@@ -46,17 +49,24 @@ public override async Task RegisterCodeFixesAsync(CodeFixContext context)
             var text = await document.GetTextAsync(cancellationToken).ConfigureAwait(false);
 
             var startTrivia = root.FindTrivia(context.Span.Start);
-
             if (!IsConflictMarker(text, startTrivia, '<'))
-            {
                 return;
-            }
 
+            var conflictTrivia = TryGetConflictTrivia(text, startTrivia);
+            if (conflictTrivia == null)
+                return;
+
+            var (equalsTrivia, endTrivia) = conflictTrivia.Value;
+            RegisterCodeFixes(context, startTrivia, equalsTrivia, endTrivia);
+        }
+
+        private (SyntaxTrivia equalsTrivia, SyntaxTrivia endTrivia)? TryGetConflictTrivia(SourceText text, SyntaxTrivia startTrivia)
+        {
             var token = startTrivia.Token;
 
             while (true)
             {
-                var index = GetEqualsConflictMarkerIndex(text, token);
+                var index = GetEqualsConflictMarkerIndex(text, token, afterPosition: startTrivia.SpanStart);
                 if (index >= 0)
                 {
                     var leadingTrivia = token.LeadingTrivia;
@@ -74,8 +84,7 @@ public override async Task RegisterCodeFixesAsync(CodeFixContext context)
                             _syntaxKinds.DisabledTextTrivia == disabledTrivia.RawKind &&
                             IsConflictMarker(text, endTrivia, '>'))
                         {
-                            RegisterCodeFixes(context, startTrivia, equalsTrivia, endTrivia);
-                            return;
+                            return (equalsTrivia, endTrivia);
                         }
                     }
 
@@ -90,8 +99,7 @@ public override async Task RegisterCodeFixesAsync(CodeFixContext context)
                         if (_syntaxKinds.EndOfLineTrivia == endOfLineTrivia.RawKind &&
                             IsConflictMarker(text, endTrivia, '>'))
                         {
-                            RegisterCodeFixes(context, startTrivia, equalsTrivia, endTrivia);
-                            return;
+                            return (equalsTrivia, endTrivia);
                         }
                     }
                 }
@@ -99,7 +107,7 @@ public override async Task RegisterCodeFixesAsync(CodeFixContext context)
                 token = token.GetNextToken(includeZeroWidth: true);
                 if (token.RawKind == 0)
                 {
-                    return;
+                    return null;
                 }
             }
         }
@@ -125,77 +133,99 @@ public override async Task RegisterCodeFixesAsync(CodeFixContext context)
 
             context.RegisterCodeFix(
                 new MyCodeAction(takeTopText,
-                    c => TakeTopAsync(document, startPos, equalsPos, endPos, c)),
+                    c => TakeTopAsync(document, startPos, equalsPos, endPos, c),
+                    TakeTopEquivalenceKey),
                 context.Diagnostics);
             context.RegisterCodeFix(
                 new MyCodeAction(takeBottomText,
-                    c => TakeBottomAsync(document, startPos, equalsPos, endPos, c)),
+                    c => TakeBottomAsync(document, startPos, equalsPos, endPos, c),
+                    TakeBottomEquivalenceKey),
                 context.Diagnostics);
             context.RegisterCodeFix(
                 new MyCodeAction(FeaturesResources.Take_both,
-                    c => TakeBothAsync(document, startPos, equalsPos, endPos, c)),
+                    c => TakeBothAsync(document, startPos, equalsPos, endPos, c),
+                    TakeBothEquivalenceKey),
                 context.Diagnostics);
         }
 
-        private async Task<Document> TakeTopAsync(
+        private async Task<Document> AddEditsAsync(
             Document document, int startPos, int equalsPos, int endPos,
+            Action<SourceText, ArrayBuilder<TextChange>, int, int, int> addEdits,
             CancellationToken cancellationToken)
         {
             var text = await document.GetTextAsync(cancellationToken).ConfigureAwait(false);
 
-            var bottomEnd = GetEndIncludingLineBreak(text, endPos);
-            var newText = text.Replace(TextSpan.FromBounds(equalsPos, bottomEnd), "");
+            using var _ = ArrayBuilder<TextChange>.GetInstance(out var edits);
+            addEdits(text, edits, startPos, equalsPos, endPos);
 
-            var startEnd = GetEndIncludingLineBreak(text, startPos);
-            var finaltext = newText.Replace(TextSpan.FromBounds(startPos, startEnd), "");
-
-            return document.WithText(finaltext);
+            var finalText = text.WithChanges(edits);
+            return document.WithText(finalText);
         }
 
-        private async Task<Document> TakeBottomAsync(
-            Document document, int startPos, int equalsPos, int endPos,
-            CancellationToken cancellationToken)
+        private static void AddTopEdits(
+            SourceText text, ArrayBuilder<TextChange> edits,
+            int startPos, int equalsPos, int endPos)
         {
-            var text = await document.GetTextAsync(cancellationToken).ConfigureAwait(false);
+            // Delete the line containing <<<<<<<
+            var startEnd = GetEndIncludingLineBreak(text, startPos);
+            edits.Add(new TextChange(TextSpan.FromBounds(startPos, startEnd), ""));
 
+            // Remove the chunk of text (inclusive) from ======= through >>>>>>>
             var bottomEnd = GetEndIncludingLineBreak(text, endPos);
-            var newText = text.Replace(TextSpan.FromBounds(endPos, bottomEnd), "");
+            edits.Add(new TextChange(TextSpan.FromBounds(equalsPos, bottomEnd), ""));
+        }
 
+        private static void AddBottomEdits(
+            SourceText text, ArrayBuilder<TextChange> edits,
+            int startPos, int equalsPos, int endPos)
+        {
+            // Remove the chunk of text (inclusive) from <<<<<<< through =======
             var equalsEnd = GetEndIncludingLineBreak(text, equalsPos);
-            var finaltext = newText.Replace(TextSpan.FromBounds(startPos, equalsEnd), "");
+            edits.Add(new TextChange(TextSpan.FromBounds(startPos, equalsEnd), ""));
 
-            return document.WithText(finaltext);
+            // Delete the line containing >>>>>>> 
+            var bottomEnd = GetEndIncludingLineBreak(text, endPos);
+            edits.Add(new TextChange(TextSpan.FromBounds(endPos, bottomEnd), ""));
         }
 
-        private async Task<Document> TakeBothAsync(
-            Document document, int startPos, int equalsPos, int endPos,
-            CancellationToken cancellationToken)
+        private static void AddBothEdits(
+            SourceText text, ArrayBuilder<TextChange> edits,
+            int startPos, int equalsPos, int endPos)
         {
-            var text = await document.GetTextAsync(cancellationToken).ConfigureAwait(false);
+            // Delete the line containing <<<<<<<
+            var startEnd = GetEndIncludingLineBreak(text, startPos);
+            edits.Add(new TextChange(TextSpan.FromBounds(startPos, startEnd), ""));
+
+            // Delete the line containing =======
+            var equalsEnd = GetEndIncludingLineBreak(text, equalsPos);
+            edits.Add(new TextChange(TextSpan.FromBounds(equalsPos, equalsEnd), ""));
 
+            // Delete the line containing >>>>>>>
             var bottomEnd = GetEndIncludingLineBreak(text, endPos);
-            var newText = text.Replace(TextSpan.FromBounds(endPos, bottomEnd), "");
+            edits.Add(new TextChange(TextSpan.FromBounds(endPos, bottomEnd), ""));
+        }
 
-            var equalsEnd = GetEndIncludingLineBreak(text, equalsPos);
-            newText = newText.Replace(TextSpan.FromBounds(equalsPos, equalsEnd), "");
+        private Task<Document> TakeTopAsync(Document document, int startPos, int equalsPos, int endPos, CancellationToken cancellationToken)
+            => AddEditsAsync(document, startPos, equalsPos, endPos, AddTopEdits, cancellationToken);
 
-            var startEnd = GetEndIncludingLineBreak(text, startPos);
-            var finaltext = newText.Replace(TextSpan.FromBounds(startPos, startEnd), "");
+        private Task<Document> TakeBottomAsync(Document document, int startPos, int equalsPos, int endPos, CancellationToken cancellationToken)
+            => AddEditsAsync(document, startPos, equalsPos, endPos, AddBottomEdits, cancellationToken);
 
-            return document.WithText(finaltext);
-        }
+        private Task<Document> TakeBothAsync(Document document, int startPos, int equalsPos, int endPos, CancellationToken cancellationToken)
+            => AddEditsAsync(document, startPos, equalsPos, endPos, AddBothEdits, cancellationToken);
 
-        private int GetEndIncludingLineBreak(SourceText text, int position)
+        private static int GetEndIncludingLineBreak(SourceText text, int position)
             => text.Lines.GetLineFromPosition(position).SpanIncludingLineBreak.End;
 
-        private int GetEqualsConflictMarkerIndex(SourceText text, SyntaxToken token)
+        private int GetEqualsConflictMarkerIndex(SourceText text, SyntaxToken token, int afterPosition)
         {
             if (token.HasLeadingTrivia)
             {
                 var i = 0;
                 foreach (var trivia in token.LeadingTrivia)
                 {
-                    if (IsConflictMarker(text, trivia, '='))
+                    if (trivia.SpanStart >= afterPosition &&
+                        IsConflictMarker(text, trivia, '='))
                     {
                         return i;
                     }
@@ -207,11 +237,6 @@ private int GetEqualsConflictMarkerIndex(SourceText text, SyntaxToken token)
             return -1;
         }
 
-        private SyntaxTrivia GetEqualsConflictMarker(SyntaxToken token)
-        {
-            throw new NotImplementedException();
-        }
-
         private bool IsConflictMarker(SourceText text, SyntaxTrivia trivia, char ch)
         {
             return
@@ -220,10 +245,75 @@ private bool IsConflictMarker(SourceText text, SyntaxTrivia trivia, char ch)
                 text[trivia.SpanStart] == ch;
         }
 
+        private async Task<SyntaxNode> FixAllAsync(
+            Document document, ImmutableArray<Diagnostic> diagnostics,
+            string equivalenceKey, CancellationToken cancellationToken)
+        {
+            Debug.Assert(
+                equivalenceKey == TakeTopEquivalenceKey ||
+                equivalenceKey == TakeBottomEquivalenceKey ||
+                equivalenceKey == TakeBothEquivalenceKey);
+
+            // Process diagnostics in order so we produce edits in the right order.
+            var orderedDiagnostics = diagnostics.OrderBy(
+                (d1, d2) => d1.Location.SourceSpan.Start - d2.Location.SourceSpan.Start).ToImmutableArray();
+
+            var text = await document.GetTextAsync(cancellationToken).ConfigureAwait(false);
+            var root = await document.GetRequiredSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
+
+            // Create a single array of edits to apply.  Then walk over all the
+            // conflict-marker-regions we want to fix and add the edits for each
+            // region into that array.  Then apply the array just once to get the
+            // final document.
+            using var _ = ArrayBuilder<TextChange>.GetInstance(out var edits);
+
+            foreach (var diagnostic in diagnostics)
+            {
+                var startTrivia = root.FindTrivia(diagnostic.Location.SourceSpan.Start);
+
+                // We'll be called on all the conflict marker diagnostics (i.e. for <<<<<<< =======
+                // and >>>>>>>). We only care about the <<<<<<< ones as that controls which chunks
+                // we'll be processing.
+                if (!IsConflictMarker(text, startTrivia, '<'))
+                    continue;
+
+                var conflictTrivia = TryGetConflictTrivia(text, startTrivia);
+                if (conflictTrivia == null)
+                    continue;
+
+                var startPos = startTrivia.SpanStart;
+                var equalsPos = conflictTrivia.Value.equalsTrivia.SpanStart;
+                var endPos = conflictTrivia.Value.endTrivia.SpanStart;
+
+                switch (equivalenceKey)
+                {
+                    case TakeTopEquivalenceKey:
+                        AddTopEdits(text, edits, startPos, equalsPos, endPos);
+                        continue;
+
+                    case TakeBottomEquivalenceKey:
+                        AddBottomEdits(text, edits, startPos, equalsPos, endPos);
+                        continue;
+
+                    case TakeBothEquivalenceKey:
+                        AddBothEdits(text, edits, startPos, equalsPos, endPos);
+                        continue;
+
+                    default:
+                        throw ExceptionUtilities.UnexpectedValue(equivalenceKey);
+                }
+            }
+
+            var finalText = text.WithChanges(edits);
+            var finalDoc = document.WithText(finalText);
+
+            return await finalDoc.GetRequiredSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
+        }
+
         private class MyCodeAction : CodeAction.DocumentChangeAction
         {
-            public MyCodeAction(string title, Func<CancellationToken, Task<Document>> createChangedDocument)
-                : base(title, createChangedDocument)
+            public MyCodeAction(string title, Func<CancellationToken, Task<Document>> createChangedDocument, string equivalenceKey)
+                : base(title, createChangedDocument, equivalenceKey)
             {
             }
         }

src/Features/Core/Portable/ConflictMarkerResolution/ConflictMarkerFixAllProvider.cs

+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+#nullable enable
+
+using System.Collections.Immutable;
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.CodeFixes;
+using Microsoft.CodeAnalysis.CodeStyle;
+
+namespace Microsoft.CodeAnalysis.ConflictMarkerResolution
+{
+    internal abstract partial class AbstractResolveConflictMarkerCodeFixProvider
+    {
+        private class ConflictMarkerFixAllProvider : DocumentBasedFixAllProvider
+        {
+            private readonly AbstractResolveConflictMarkerCodeFixProvider _codeFixProvider;
+
+            public ConflictMarkerFixAllProvider(AbstractResolveConflictMarkerCodeFixProvider codeFixProvider)
+                => _codeFixProvider = codeFixProvider;
+
+            protected override string CodeActionTitle
+                => FeaturesResources.Resolve_conflict_markers;
+
+            protected override Task<SyntaxNode> FixAllInDocumentAsync(FixAllContext fixAllContext, Document document, ImmutableArray<Diagnostic> diagnostics)
+                => _codeFixProvider.FixAllAsync(document, diagnostics, fixAllContext.CodeActionEquivalenceKey, fixAllContext.CancellationToken);
+        }
+    }
+}

src/Features/Core/Portable/FeaturesResources.resx

@@ -1762,4 +1762,7 @@ This version used in: {2}</value>
   <data name="Implement_explicitly" xml:space="preserve">
     <value>Implement explicitly</value>
   </data>
+  <data name="Resolve_conflict_markers" xml:space="preserve">
+    <value>Resolve conflict markers</value>
+  </data>
 </root>
\ No newline at end of file

src/Features/Core/Portable/xlf/FeaturesResources.cs.xlf

@@ -547,6 +547,11 @@
         <target state="translated">Místo {0} použijte {1}</target>
         <note />
       </trans-unit>
+      <trans-unit id="Resolve_conflict_markers">
+        <source>Resolve conflict markers</source>
+        <target state="new">Resolve conflict markers</target>
+        <note />
+      </trans-unit>
       <trans-unit id="RudeEdit">
         <source>Rude edit</source>
         <target state="translated">Hrubá úprava</target>

src/Features/Core/Portable/xlf/FeaturesResources.de.xlf

@@ -547,6 +547,11 @@
         <target state="translated">"{0}" durch "{1}" ersetzen</target>
         <note />
       </trans-unit>
+      <trans-unit id="Resolve_conflict_markers">
+        <source>Resolve conflict markers</source>
+        <target state="new">Resolve conflict markers</target>
+        <note />
+      </trans-unit>
       <trans-unit id="RudeEdit">
         <source>Rude edit</source>
         <target state="translated">Grobe Bearbeitung</target>

src/Features/Core/Portable/xlf/FeaturesResources.es.xlf

@@ -547,6 +547,11 @@
         <target state="translated">Reemplazar "{0}" por "{1}"</target>
         <note />
       </trans-unit>
+      <trans-unit id="Resolve_conflict_markers">
+        <source>Resolve conflict markers</source>
+        <target state="new">Resolve conflict markers</target>
+        <note />
+      </trans-unit>
       <trans-unit id="RudeEdit">
         <source>Rude edit</source>
         <target state="translated">Edición superficial</target>

src/Features/Core/Portable/xlf/FeaturesResources.fr.xlf

@@ -547,6 +547,11 @@
         <target state="translated">Remplacer '{0}' par '{1}'</target>
         <note />
       </trans-unit>
+      <trans-unit id="Resolve_conflict_markers">
+        <source>Resolve conflict markers</source>
+        <target state="new">Resolve conflict markers</target>
+        <note />
+      </trans-unit>
       <trans-unit id="RudeEdit">
         <source>Rude edit</source>
         <target state="translated">Modification non applicable</target>

src/Features/Core/Portable/xlf/FeaturesResources.it.xlf

@@ -547,6 +547,11 @@
         <target state="translated">Sostituisci '{0}' con '{1}'</target>
         <note />
       </trans-unit>
+      <trans-unit id="Resolve_conflict_markers">
+        <source>Resolve conflict markers</source>
+        <target state="new">Resolve conflict markers</target>
+        <note />
+      </trans-unit>
       <trans-unit id="RudeEdit">
         <source>Rude edit</source>
         <target state="translated">Modifica non applicabile</target>

src/Features/Core/Portable/xlf/FeaturesResources.ja.xlf

@@ -547,6 +547,11 @@
         <target state="translated">'{0}' を '{1}' に置き換える</target>
         <note />
       </trans-unit>
+      <trans-unit id="Resolve_conflict_markers">
+        <source>Resolve conflict markers</source>
+        <target state="new">Resolve conflict markers</target>
+        <note />
+      </trans-unit>
       <trans-unit id="RudeEdit">
         <source>Rude edit</source>
         <target state="translated">Rude 編集</target>

src/Features/Core/Portable/xlf/FeaturesResources.ko.xlf

@@ -547,6 +547,11 @@
         <target state="translated">'{0}'을(를) '{1}'(으)로 바꾸기</target>
         <note />
       </trans-unit>
+      <trans-unit id="Resolve_conflict_markers">
+        <source>Resolve conflict markers</source>
+        <target state="new">Resolve conflict markers</target>
+        <note />
+      </trans-unit>
       <trans-unit id="RudeEdit">
         <source>Rude edit</source>
         <target state="translated">편집 다시 실행</target>

src/Features/Core/Portable/xlf/FeaturesResources.pl.xlf

@@ -547,6 +547,11 @@
         <target state="translated">Zamień element „{0}” na element „{1}”</target>
         <note />
       </trans-unit>
+      <trans-unit id="Resolve_conflict_markers">
+        <source>Resolve conflict markers</source>
+        <target state="new">Resolve conflict markers</target>
+        <note />
+      </trans-unit>
       <trans-unit id="RudeEdit">
         <source>Rude edit</source>
         <target state="translated">Edycja reguły</target>

src/Features/Core/Portable/xlf/FeaturesResources.pt-BR.xlf

@@ -547,6 +547,11 @@
         <target state="translated">Substituir '{0}' por '{1}'</target>
         <note />
       </trans-unit>
+      <trans-unit id="Resolve_conflict_markers">
+        <source>Resolve conflict markers</source>
+        <target state="new">Resolve conflict markers</target>
+        <note />
+      </trans-unit>
       <trans-unit id="RudeEdit">
         <source>Rude edit</source>
         <target state="translated">Edição rudimentar</target>

src/Features/Core/Portable/xlf/FeaturesResources.ru.xlf

@@ -547,6 +547,11 @@
         <target state="translated">Замените '{0}' на '{1}'</target>
         <note />
       </trans-unit>
+      <trans-unit id="Resolve_conflict_markers">
+        <source>Resolve conflict markers</source>
+        <target state="new">Resolve conflict markers</target>
+        <note />
+      </trans-unit>
       <trans-unit id="RudeEdit">
         <source>Rude edit</source>
         <target state="translated">Грубая редакция</target>

src/Features/Core/Portable/xlf/FeaturesResources.tr.xlf

@@ -547,6 +547,11 @@
         <target state="translated">'{0}' öğesini '{1}' ile değiştir</target>
         <note />
       </trans-unit>
+      <trans-unit id="Resolve_conflict_markers">
+        <source>Resolve conflict markers</source>
+        <target state="new">Resolve conflict markers</target>
+        <note />
+      </trans-unit>
       <trans-unit id="RudeEdit">
         <source>Rude edit</source>
         <target state="translated">İşlenmemiş düzenleme</target>

src/Features/Core/Portable/xlf/FeaturesResources.zh-Hans.xlf

@@ -547,6 +547,11 @@
         <target state="translated">将 "{0}" 替换为 "{1}"</target>
         <note />
       </trans-unit>
+      <trans-unit id="Resolve_conflict_markers">
+        <source>Resolve conflict markers</source>
+        <target state="new">Resolve conflict markers</target>
+        <note />
+      </trans-unit>
       <trans-unit id="RudeEdit">
         <source>Rude edit</source>
         <target state="translated">原始编辑</target>

src/Features/Core/Portable/xlf/FeaturesResources.zh-Hant.xlf

@@ -547,6 +547,11 @@
         <target state="translated">將 ‘{0}’ 取代為 ‘{1}'</target>
         <note />
       </trans-unit>
+      <trans-unit id="Resolve_conflict_markers">
+        <source>Resolve conflict markers</source>
+        <target state="new">Resolve conflict markers</target>
+        <note />
+      </trans-unit>
       <trans-unit id="RudeEdit">
         <source>Rude edit</source>
         <target state="translated">粗略編輯</target>

src/Workspaces/SharedUtilitiesAndExtensions/Workspace/Core/CodeFixes/DocumentBasedFixAllProvider.cs

@@ -8,6 +8,8 @@
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis.CodeActions;
 using Microsoft.CodeAnalysis.CodeFixes;
+using Microsoft.CodeAnalysis.PooledObjects;
+using Roslyn.Utilities;
 
 #pragma warning disable RS0005 // Do not use generic CodeAction.Create to create CodeAction
 
@@ -92,28 +94,28 @@ private async Task<Solution> GetSolutionFixesAsync(FixAllContext fixAllContext,
         {
             var documentDiagnosticsToFix = await FixAllContextHelper.GetDocumentDiagnosticsToFixAsync(fixAllContext, progressTrackerOpt: null).ConfigureAwait(false);
 
-            var solution = fixAllContext.Solution;
-            var newDocuments = new List<Task<SyntaxNode>>(documents.Length);
+            using var _ = PooledDictionary<DocumentId, Task<SyntaxNode>>.GetInstance(out var documentIdToNewNode);
             foreach (var document in documents)
             {
+                // Don't bother examining any documents that aren't in the list of docs that
+                // actually have diagnostics.
                 if (!documentDiagnosticsToFix.TryGetValue(document, out var diagnostics))
-                {
-                    newDocuments.Add(document.GetSyntaxRootAsync(fixAllContext.CancellationToken));
                     continue;
-                }
 
-                newDocuments.Add(FixAllInDocumentAsync(fixAllContext, document, diagnostics));
+                documentIdToNewNode.Add(document.Id, FixAllInDocumentAsync(fixAllContext, document, diagnostics));
             }
 
-            for (var i = 0; i < documents.Length; i++)
+            // Allow the processing of all the documents to happen concurrently.
+            await Task.WhenAll(documentIdToNewNode.Values).ConfigureAwait(false);
+
+            var solution = fixAllContext.Solution;
+            foreach (var (docId, syntaxNodeTask) in documentIdToNewNode)
             {
-                var newDocumentRoot = await newDocuments[i].ConfigureAwait(false);
+                var newDocumentRoot = await syntaxNodeTask.ConfigureAwait(false);
                 if (newDocumentRoot == null)
-                {
                     continue;
-                }
 
-                solution = solution.WithDocumentSyntaxRoot(documents[i].Id, newDocumentRoot);
+                solution = solution.WithDocumentSyntaxRoot(docId, newDocumentRoot);
             }
 
             return solution;