Revert "Handle textDocument/didChange notifications that don't pass a… (#78227)

…cross the range (#78165)"

This reverts commit 59eae07, reversing
changes made to 20e9836.

Breaks Razor

```
04/19/2025 07:45:59.186 [9876]: 2>Warning: System.MissingMethodException: Method not found: 'Roslyn.LanguageServer.Protocol.TextDocumentContentChangeEvent[] Roslyn.LanguageServer.Protocol.DidChangeTextDocumentParams.get_ContentChanges()'. while resolving 0xa0007f6 - Roslyn.LanguageServer.Protocol.DidChangeTextDocumentParams.get_ContentChanges.
04/19/2025 07:45:59.608 [9876]: 2>Method not found: 'Roslyn.LanguageServer.Protocol.TextDocumentContentChangeEvent[] Roslyn.LanguageServer.Protocol.DidChangeTextDocumentParams.get_ContentChanges()'. while compiling method <HandleNotificationAsync>d__7.MoveNext
```

Author: dibarbet

src/LanguageServer/Protocol.TestUtilities/LanguageServer/AbstractLanguageServerProtocolTests.cs

@@ -500,16 +500,13 @@ private static string GetDocumentFilePathFromName(string documentName)
 
     private static LSP.DidChangeTextDocumentParams CreateDidChangeTextDocumentParams(
         Uri documentUri,
-        ImmutableArray<(LSP.Range? Range, string Text)> changes)
+        ImmutableArray<(LSP.Range Range, string Text)> changes)
     {
-        var changeEvents = new LSP.SumType<LSP.TextDocumentContentChangeEvent, LSP.TextDocumentContentChangeFullReplacementEvent>[changes.Length];
-        for (var i = 0; i < changes.Length; i++)
+        var changeEvents = changes.Select(change => new LSP.TextDocumentContentChangeEvent
         {
-            var (range, text) = changes[i];
-            changeEvents[i] = range != null
-                ? new LSP.TextDocumentContentChangeEvent { Text = text, Range = range }
-                : new LSP.TextDocumentContentChangeFullReplacementEvent { Text = text };
-        }
+            Text = change.Text,
+            Range = change.Range,
+        }).ToArray();
 
         return new LSP.DidChangeTextDocumentParams()
         {
@@ -747,30 +744,21 @@ public async Task OpenDocumentInWorkspaceAsync(DocumentId documentId, bool openA
             await WaitForWorkspaceOperationsAsync(TestWorkspace);
         }
 
-        public Task ReplaceTextAsync(Uri documentUri, params (LSP.Range? Range, string Text)[] changes)
+        public Task ReplaceTextAsync(Uri documentUri, params (LSP.Range Range, string Text)[] changes)
         {
             var didChangeParams = CreateDidChangeTextDocumentParams(
                 documentUri,
                 [.. changes]);
             return ExecuteRequestAsync<LSP.DidChangeTextDocumentParams, object>(LSP.Methods.TextDocumentDidChangeName, didChangeParams, CancellationToken.None);
         }
 
-        public Task InsertTextAsync(Uri documentUri, params (int? Line, int? Column, string Text)[] changes)
+        public Task InsertTextAsync(Uri documentUri, params (int Line, int Column, string Text)[] changes)
         {
-            var rangeChanges = new List<(LSP.Range? Range, string Text)>();
-            foreach (var (line, column, text) in changes)
+            return ReplaceTextAsync(documentUri, [.. changes.Select(change => (new LSP.Range
             {
-                var range = (line is null || column is null)
-                    ? null
-                    : new LSP.Range
-                    {
-                        Start = new LSP.Position { Line = line.Value, Character = column.Value },
-                        End = new LSP.Position { Line = line.Value, Character = column.Value }
-                    };
-                rangeChanges.Add((range, text));
-            }
-
-            return ReplaceTextAsync(documentUri, [.. rangeChanges]);
+                Start = new LSP.Position { Line = change.Line, Character = change.Column },
+                End = new LSP.Position { Line = change.Line, Character = change.Column }
+            }, change.Text))]);
         }
 
         public Task DeleteTextAsync(Uri documentUri, params (int StartLine, int StartColumn, int EndLine, int EndColumn)[] changes)

src/LanguageServer/Protocol/Handler/DocumentChanges/DidChangeHandler.cs

@@ -3,7 +3,6 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
-using System.Collections.Immutable;
 using System.Composition;
 using System.Linq;
 using System.Threading;
@@ -38,7 +37,7 @@ public TextDocumentIdentifier GetTextDocumentIdentifier(DidChangeTextDocumentPar
         return SpecializedTasks.Default<object>();
     }
 
-    internal static bool AreChangesInReverseOrder(ImmutableArray<TextDocumentContentChangeEvent> contentChanges)
+    internal static bool AreChangesInReverseOrder(TextDocumentContentChangeEvent[] contentChanges)
     {
         for (var i = 1; i < contentChanges.Length; i++)
         {
@@ -54,14 +53,8 @@ internal static bool AreChangesInReverseOrder(ImmutableArray<TextDocumentContent
         return true;
     }
 
-    private static SourceText GetUpdatedSourceText(SumType<TextDocumentContentChangeEvent, TextDocumentContentChangeFullReplacementEvent>[] contentChanges, SourceText text)
+    private static SourceText GetUpdatedSourceText(TextDocumentContentChangeEvent[] contentChanges, SourceText text)
     {
-        (var remainingContentChanges, text) = GetUpdatedSourceTextAndChangesAfterFullTextReplacementHandled(contentChanges, text);
-
-        // No range-based changes to apply.
-        if (remainingContentChanges.IsEmpty)
-            return text;
-
         // Per the LSP spec, each text change builds upon the previous, so we don't need to translate any text
         // positions between changes. See
         // https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#didChangeTextDocumentParams
@@ -70,41 +63,20 @@ private static SourceText GetUpdatedSourceText(SumType<TextDocumentContentChange
         // If the host sends us changes in a way such that no earlier change can affect the position of a later change,
         // then we can merge the changes into a single TextChange, allowing creation of only a single new
         // source text.
-        if (AreChangesInReverseOrder(remainingContentChanges))
+        if (AreChangesInReverseOrder(contentChanges))
         {
             // The changes were in reverse document order, so we can merge them into a single operation on the source text.
             // Note that the WithChanges implementation works more efficiently with it's input in forward document order.
-            var newChanges = remainingContentChanges.Reverse().SelectAsArray(change => ProtocolConversions.ContentChangeEventToTextChange(change, text));
+            var newChanges = contentChanges.Reverse().SelectAsArray(change => ProtocolConversions.ContentChangeEventToTextChange(change, text));
             text = text.WithChanges(newChanges);
         }
         else
         {
             // The host didn't send us the items ordered, so we'll apply each one independently.
-            foreach (var change in remainingContentChanges)
+            foreach (var change in contentChanges)
                 text = text.WithChanges(ProtocolConversions.ContentChangeEventToTextChange(change, text));
         }
 
         return text;
     }
-
-    private static (ImmutableArray<TextDocumentContentChangeEvent>, SourceText) GetUpdatedSourceTextAndChangesAfterFullTextReplacementHandled(SumType<TextDocumentContentChangeEvent, TextDocumentContentChangeFullReplacementEvent>[] contentChanges, SourceText text)
-    {
-        // Per the LSP spec, each content change can be either a TextDocumentContentChangeEvent or TextDocumentContentChangeFullReplacementEvent.
-        // The former is a range-based change while the latter is a full text replacement. If a TextDocumentContentChangeFullReplacementEvent is found,
-        // then make a full text replacement for that and return all subsequent changes as remaining range-based changes.
-        var lastFullTextChangeEventIndex = contentChanges.Length - 1;
-        for (; lastFullTextChangeEventIndex >= 0; lastFullTextChangeEventIndex--)
-        {
-            var change = contentChanges[lastFullTextChangeEventIndex];
-            if (change.Value is TextDocumentContentChangeFullReplacementEvent onlyTextEvent)
-            {
-                // Found a full text replacement. Create the new text and stop processing.
-                text = text.WithChanges([new TextChange(new TextSpan(0, text.Length), onlyTextEvent.Text)]);
-                break;
-            }
-        }
-
-        var remainingContentChanges = contentChanges.Skip(lastFullTextChangeEventIndex + 1).SelectAsArray(c => c.First);
-        return (remainingContentChanges, text);
-    }
 }

src/LanguageServer/Protocol/Protocol/DidChangeTextDocumentParams.cs

@@ -45,7 +45,7 @@ public VersionedTextDocumentIdentifier TextDocument
     /// </summary>
     [JsonPropertyName("contentChanges")]
     [JsonRequired]
-    public SumType<TextDocumentContentChangeEvent, TextDocumentContentChangeFullReplacementEvent>[] ContentChanges
+    public TextDocumentContentChangeEvent[] ContentChanges
     {
         get;
         set;

src/LanguageServer/Protocol/Protocol/TextDocumentContentChangeEvent.cs

@@ -18,7 +18,6 @@ internal sealed class TextDocumentContentChangeEvent
     /// Gets or sets the range of the text that was changed.
     /// </summary>
     [JsonPropertyName("range")]
-    [JsonRequired]
     public Range Range
     {
         get;
@@ -40,7 +39,6 @@ public int? RangeLength
     /// Gets or sets the new text of the range/document.
     /// </summary>
     [JsonPropertyName("text")]
-    [JsonRequired]
     public string Text
     {
         get;

src/LanguageServer/Protocol/Protocol/TextDocumentContentChangeFullReplacementEvent.cs

@@ -448,40 +448,6 @@ void M()
         }
     }
 
-    [Theory, CombinatorialData]
-    public async Task DidChange_MultipleRequestsIncludingTextOnly(bool mutatingLspWorkspace)
-    {
-        var source =
-            """
-            {|type:|}
-            """;
-        var expected =
-            """
-            /* test */
-            """;
-
-        var (testLspServer, locationTyped, _) = await GetTestLspServerAndLocationAsync(source, mutatingLspWorkspace);
-
-        await using (testLspServer)
-        {
-            await DidOpen(testLspServer, locationTyped.Uri);
-
-            var changes = new (int? line, int? column, string text)[]
-            {
-                (0, 0, "// hi"),
-                (null, null, "/*  */"),
-                (0, 3, "test"),
-            };
-
-            await DidChange(testLspServer, locationTyped.Uri, changes);
-
-            var document = testLspServer.GetTrackedTexts().FirstOrDefault();
-
-            AssertEx.NotNull(document);
-            Assert.Equal(expected, document.ToString());
-        }
-    }
-
     private async Task<(TestLspServer, LSP.Location, string)> GetTestLspServerAndLocationAsync(string source, bool mutatingLspWorkspace)
     {
         var testLspServer = await CreateTestLspServerAsync(source, mutatingLspWorkspace, CapabilitiesWithVSExtensions);
@@ -493,7 +459,7 @@ public async Task DidChange_MultipleRequestsIncludingTextOnly(bool mutatingLspWo
 
     private static Task DidOpen(TestLspServer testLspServer, Uri uri) => testLspServer.OpenDocumentAsync(uri);
 
-    private static async Task DidChange(TestLspServer testLspServer, Uri uri, params (int? line, int? column, string text)[] changes)
+    private static async Task DidChange(TestLspServer testLspServer, Uri uri, params (int line, int column, string text)[] changes)
         => await testLspServer.InsertTextAsync(uri, changes);
 
     private static async Task DidClose(TestLspServer testLspServer, Uri uri) => await testLspServer.CloseDocumentAsync(uri);