From a9804e3259d6335ef1b2706b6e5efa95c0fc83b7 Mon Sep 17 00:00:00 2001
From: Danny Tuppeny <danny@tuppeny.com>
Date: Thu, 12 May 2022 15:46:25 +0000
Subject: [PATCH] [analysis_server] Simplify types for LSP documentChanges

+ add ToJsonable to enums.

Change-Id: I1c51258f84d3aa27f82986be759483d7985475d6
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/244624
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>
---
 .../lib/lsp_protocol/protocol_generated.dart  | 139 +++++++++---------
 pkg/analysis_server/lib/src/lsp/mapping.dart  |  34 +----
 .../test/lsp/code_actions_assists_test.dart   |  34 ++---
 .../test/lsp/server_abstract.dart             |  41 ++----
 .../test/tool/lsp_spec/json_test.dart         |   2 +-
 .../tool/lsp_spec/codegen_dart.dart           |   2 +-
 .../tool/lsp_spec/typescript_parser.dart      |  12 ++
 7 files changed, 114 insertions(+), 150 deletions(-)

diff --git a/pkg/analysis_server/lib/lsp_protocol/protocol_generated.dart b/pkg/analysis_server/lib/lsp_protocol/protocol_generated.dart
index 699d04ebdb2..92f7af42251 100644
--- a/pkg/analysis_server/lib/lsp_protocol/protocol_generated.dart
+++ b/pkg/analysis_server/lib/lsp_protocol/protocol_generated.dart
@@ -3262,7 +3262,7 @@ class CodeActionDisabled implements ToJsonable {
 }
 
 /// A set of predefined code action kinds.
-class CodeActionKind {
+class CodeActionKind implements ToJsonable {
   const CodeActionKind(this._value);
   const CodeActionKind.fromJson(this._value);
 
@@ -3807,7 +3807,7 @@ class CodeActionRegistrationOptions
 
 /// The reason why code actions were requested.
 ///  @since 3.17.0
-class CodeActionTriggerKind {
+class CodeActionTriggerKind implements ToJsonable {
   const CodeActionTriggerKind(this._value);
   const CodeActionTriggerKind.fromJson(this._value);
 
@@ -6786,7 +6786,7 @@ class CompletionItem implements ToJsonable {
 }
 
 /// The kind of a completion entry.
-class CompletionItemKind {
+class CompletionItemKind implements ToJsonable {
   const CompletionItemKind(this._value);
   const CompletionItemKind.fromJson(this._value);
 
@@ -6928,7 +6928,7 @@ class CompletionItemLabelDetails implements ToJsonable {
 /// Completion item tags are extra annotations that tweak the rendering of a
 /// completion item.
 ///  @since 3.15.0
-class CompletionItemTag {
+class CompletionItemTag implements ToJsonable {
   const CompletionItemTag(this._value);
   const CompletionItemTag.fromJson(this._value);
 
@@ -8017,7 +8017,7 @@ class CompletionRegistrationOptions
 }
 
 /// How a completion was triggered
-class CompletionTriggerKind {
+class CompletionTriggerKind implements ToJsonable {
   const CompletionTriggerKind._(this._value);
   const CompletionTriggerKind.fromJson(this._value);
 
@@ -10604,7 +10604,7 @@ class DiagnosticServerCancellationData implements ToJsonable {
   String toString() => jsonEncoder.convert(toJson());
 }
 
-class DiagnosticSeverity {
+class DiagnosticSeverity implements ToJsonable {
   const DiagnosticSeverity(this._value);
   const DiagnosticSeverity.fromJson(this._value);
 
@@ -10639,7 +10639,7 @@ class DiagnosticSeverity {
 
 /// The diagnostic tags.
 ///  @since 3.15.0
-class DiagnosticTag {
+class DiagnosticTag implements ToJsonable {
   const DiagnosticTag(this._value);
   const DiagnosticTag.fromJson(this._value);
 
@@ -12530,7 +12530,7 @@ class DocumentDiagnosticParams
 
 /// The document diagnostic report kinds.
 ///  @since 3.17.0
-class DocumentDiagnosticReportKind {
+class DocumentDiagnosticReportKind implements ToJsonable {
   const DocumentDiagnosticReportKind(this._value);
   const DocumentDiagnosticReportKind.fromJson(this._value);
 
@@ -13188,7 +13188,7 @@ class DocumentHighlightClientCapabilities implements ToJsonable {
 }
 
 /// A document highlight kind.
-class DocumentHighlightKind {
+class DocumentHighlightKind implements ToJsonable {
   const DocumentHighlightKind(this._value);
   const DocumentHighlightKind.fromJson(this._value);
 
@@ -15928,7 +15928,7 @@ class DocumentSymbolRegistrationOptions
   String toString() => jsonEncoder.convert(toJson());
 }
 
-class ErrorCodes {
+class ErrorCodes implements ToJsonable {
   const ErrorCodes(this._value);
   const ErrorCodes.fromJson(this._value);
 
@@ -16485,7 +16485,7 @@ class ExecutionSummary implements ToJsonable {
   String toString() => jsonEncoder.convert(toJson());
 }
 
-class FailureHandlingKind {
+class FailureHandlingKind implements ToJsonable {
   const FailureHandlingKind._(this._value);
   const FailureHandlingKind.fromJson(this._value);
 
@@ -16533,7 +16533,7 @@ class FailureHandlingKind {
 }
 
 /// The file event type.
-class FileChangeType {
+class FileChangeType implements ToJsonable {
   const FileChangeType(this._value);
   const FileChangeType.fromJson(this._value);
 
@@ -17037,7 +17037,7 @@ class FileOperationPattern implements ToJsonable {
 
 /// A pattern kind describing if a glob pattern matches a file a folder or both.
 ///  @since 3.16.0
-class FileOperationPatternKind {
+class FileOperationPatternKind implements ToJsonable {
   const FileOperationPatternKind(this._value);
   const FileOperationPatternKind.fromJson(this._value);
 
@@ -17927,7 +17927,7 @@ class FoldingRangeClientCapabilitiesFoldingRangeKind implements ToJsonable {
 }
 
 /// A set of predefined range kinds.
-class FoldingRangeKind {
+class FoldingRangeKind implements ToJsonable {
   const FoldingRangeKind(this._value);
   const FoldingRangeKind.fromJson(this._value);
 
@@ -19688,7 +19688,7 @@ class ImplementationRegistrationOptions
 }
 
 /// Known error codes for an `InitializeErrorCodes`;
-class InitializeErrorCodes {
+class InitializeErrorCodes implements ToJsonable {
   const InitializeErrorCodes(this._value);
   const InitializeErrorCodes.fromJson(this._value);
 
@@ -20783,7 +20783,7 @@ class InlayHintClientCapabilitiesResolveSupport implements ToJsonable {
 
 /// Inlay hint kinds.
 ///  @since 3.17.0
-class InlayHintKind {
+class InlayHintKind implements ToJsonable {
   const InlayHintKind(this._value);
   const InlayHintKind.fromJson(this._value);
 
@@ -22448,7 +22448,7 @@ class InsertReplaceEdit implements ToJsonable {
 
 /// Defines whether the insert text in a completion item should be interpreted
 /// as plain text or a snippet.
-class InsertTextFormat {
+class InsertTextFormat implements ToJsonable {
   const InsertTextFormat._(this._value);
   const InsertTextFormat.fromJson(this._value);
 
@@ -22487,7 +22487,7 @@ class InsertTextFormat {
 
 /// How whitespace and indentation is handled during completion item insertion.
 ///  @since 3.16.0
-class InsertTextMode {
+class InsertTextMode implements ToJsonable {
   const InsertTextMode(this._value);
   const InsertTextMode.fromJson(this._value);
 
@@ -23704,7 +23704,7 @@ class MarkupContent implements ToJsonable {
 ///
 /// Please note that `MarkupKinds` must not start with a `$`. This kinds are
 /// reserved for internal usage.
-class MarkupKind {
+class MarkupKind implements ToJsonable {
   const MarkupKind._(this._value);
   const MarkupKind.fromJson(this._value);
 
@@ -23903,7 +23903,7 @@ class MessageActionItem implements ToJsonable {
   String toString() => jsonEncoder.convert(toJson());
 }
 
-class MessageType {
+class MessageType implements ToJsonable {
   const MessageType(this._value);
   const MessageType.fromJson(this._value);
 
@@ -23937,7 +23937,7 @@ class MessageType {
 }
 
 /// Valid LSP methods known at the time of code generation from the spec.
-class Method {
+class Method implements ToJsonable {
   const Method(this._value);
   const Method.fromJson(this._value);
 
@@ -24475,7 +24475,7 @@ class MonikerClientCapabilities implements ToJsonable {
 }
 
 /// The moniker kind.
-class MonikerKind {
+class MonikerKind implements ToJsonable {
   const MonikerKind(this._value);
   const MonikerKind.fromJson(this._value);
 
@@ -25106,7 +25106,7 @@ class NotebookCellArrayChange implements ToJsonable {
 
 /// A notebook cell kind.
 ///  @since 3.17.0
-class NotebookCellKind {
+class NotebookCellKind implements ToJsonable {
   const NotebookCellKind(this._value);
   const NotebookCellKind.fromJson(this._value);
 
@@ -27539,7 +27539,7 @@ class Position implements ToJsonable {
 
 /// A set of predefined position encoding kinds.
 ///  @since 3.17.0
-class PositionEncodingKind {
+class PositionEncodingKind implements ToJsonable {
   const PositionEncodingKind(this._value);
   const PositionEncodingKind.fromJson(this._value);
 
@@ -27676,7 +27676,7 @@ class PrepareRenameParams implements TextDocumentPositionParams, ToJsonable {
   String toString() => jsonEncoder.convert(toJson());
 }
 
-class PrepareSupportDefaultBehavior {
+class PrepareSupportDefaultBehavior implements ToJsonable {
   const PrepareSupportDefaultBehavior(this._value);
   const PrepareSupportDefaultBehavior.fromJson(this._value);
 
@@ -30722,7 +30722,7 @@ class RequestMessage implements Message, IncomingMessage, ToJsonable {
   String toString() => jsonEncoder.convert(toJson());
 }
 
-class ResourceOperationKind {
+class ResourceOperationKind implements ToJsonable {
   const ResourceOperationKind._(this._value);
   const ResourceOperationKind.fromJson(this._value);
 
@@ -31615,7 +31615,7 @@ class SelectionRangeRegistrationOptions
   String toString() => jsonEncoder.convert(toJson());
 }
 
-class SemanticTokenModifiers {
+class SemanticTokenModifiers implements ToJsonable {
   const SemanticTokenModifiers(this._value);
   const SemanticTokenModifiers.fromJson(this._value);
 
@@ -31648,7 +31648,7 @@ class SemanticTokenModifiers {
       o is SemanticTokenModifiers && o._value == _value;
 }
 
-class SemanticTokenTypes {
+class SemanticTokenTypes implements ToJsonable {
   const SemanticTokenTypes(this._value);
   const SemanticTokenTypes.fromJson(this._value);
 
@@ -37241,7 +37241,7 @@ class SignatureHelpRegistrationOptions
 
 /// How a signature help was triggered.
 ///  @since 3.15.0
-class SignatureHelpTriggerKind {
+class SignatureHelpTriggerKind implements ToJsonable {
   const SignatureHelpTriggerKind(this._value);
   const SignatureHelpTriggerKind.fromJson(this._value);
 
@@ -37758,7 +37758,7 @@ class SymbolInformation implements ToJsonable {
 }
 
 /// A symbol kind.
-class SymbolKind {
+class SymbolKind implements ToJsonable {
   const SymbolKind(this._value);
   const SymbolKind.fromJson(this._value);
 
@@ -37808,7 +37808,7 @@ class SymbolKind {
 
 /// Symbol tags are extra annotations that tweak the rendering of a symbol.
 ///  @since 3.16
-class SymbolTag {
+class SymbolTag implements ToJsonable {
   const SymbolTag(this._value);
   const SymbolTag.fromJson(this._value);
 
@@ -39807,7 +39807,7 @@ class TextDocumentRegistrationOptions implements ToJsonable {
 }
 
 /// Represents reasons why a text document is saved.
-class TextDocumentSaveReason {
+class TextDocumentSaveReason implements ToJsonable {
   const TextDocumentSaveReason(this._value);
   const TextDocumentSaveReason.fromJson(this._value);
 
@@ -40078,7 +40078,7 @@ class TextDocumentSyncClientCapabilities implements ToJsonable {
 
 /// Defines how the host (editor) should sync document changes to the language
 /// server.
-class TextDocumentSyncKind {
+class TextDocumentSyncKind implements ToJsonable {
   const TextDocumentSyncKind(this._value);
   const TextDocumentSyncKind.fromJson(this._value);
 
@@ -40385,7 +40385,7 @@ class TextEdit implements ToJsonable {
   String toString() => jsonEncoder.convert(toJson());
 }
 
-class TokenFormat {
+class TokenFormat implements ToJsonable {
   const TokenFormat(this._value);
   const TokenFormat.fromJson(this._value);
 
@@ -41867,7 +41867,7 @@ class UnchangedDocumentDiagnosticReport implements ToJsonable {
 }
 
 /// Moniker uniqueness level to define scope of the moniker.
-class UniquenessLevel {
+class UniquenessLevel implements ToJsonable {
   const UniquenessLevel(this._value);
   const UniquenessLevel.fromJson(this._value);
 
@@ -42284,7 +42284,7 @@ class VersionedTextDocumentIdentifier
   String toString() => jsonEncoder.convert(toJson());
 }
 
-class WatchKind {
+class WatchKind implements ToJsonable {
   const WatchKind(this._value);
   const WatchKind.fromJson(this._value);
 
@@ -44273,26 +44273,22 @@ class WorkspaceEdit implements ToJsonable {
                 .map((item) => TextEdit.fromJson(item as Map<String, Object?>))
                 .toList()));
     final documentChangesJson = json['documentChanges'];
-    final documentChanges = documentChangesJson == null
-        ? null
-        : ((documentChangesJson is List<Object?> &&
-                (documentChangesJson.every((item) =>
-                    (CreateFile.canParse(item, nullLspJsonReporter) ||
-                        DeleteFile.canParse(item, nullLspJsonReporter) ||
-                        RenameFile.canParse(item, nullLspJsonReporter) ||
-                        TextDocumentEdit.canParse(item, nullLspJsonReporter)))))
-            ? Either2<List<Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit>>, List<TextDocumentEdit>>.t1((documentChangesJson)
-                .map((item) => CreateFile.canParse(item, nullLspJsonReporter)
-                    ? Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit>.t1(
-                        CreateFile.fromJson(item as Map<String, Object?>))
-                    : (DeleteFile.canParse(item, nullLspJsonReporter)
-                        ? Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit>.t2(
-                            DeleteFile.fromJson(item as Map<String, Object?>))
-                        : (RenameFile.canParse(item, nullLspJsonReporter)
-                            ? Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit>.t3(RenameFile.fromJson(item as Map<String, Object?>))
-                            : (TextDocumentEdit.canParse(item, nullLspJsonReporter) ? Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit>.t4(TextDocumentEdit.fromJson(item as Map<String, Object?>)) : (throw '''$item was not one of (CreateFile, DeleteFile, RenameFile, TextDocumentEdit)''')))))
-                .toList())
-            : ((documentChangesJson is List<Object?> && (documentChangesJson.every((item) => TextDocumentEdit.canParse(item, nullLspJsonReporter)))) ? Either2<List<Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit>>, List<TextDocumentEdit>>.t2((documentChangesJson).map((item) => TextDocumentEdit.fromJson(item as Map<String, Object?>)).toList()) : (throw '''$documentChangesJson was not one of (List<Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit>>, List<TextDocumentEdit>)''')));
+    final documentChanges = (documentChangesJson as List<Object?>?)
+        ?.map((item) => CreateFile.canParse(item, nullLspJsonReporter)
+            ? Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit>.t1(
+                CreateFile.fromJson(item as Map<String, Object?>))
+            : (DeleteFile.canParse(item, nullLspJsonReporter)
+                ? Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit>.t2(
+                    DeleteFile.fromJson(item as Map<String, Object?>))
+                : (RenameFile.canParse(item, nullLspJsonReporter)
+                    ? Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit>.t3(
+                        RenameFile.fromJson(item as Map<String, Object?>))
+                    : (TextDocumentEdit.canParse(item, nullLspJsonReporter)
+                        ? Either4<CreateFile, DeleteFile, RenameFile,
+                                TextDocumentEdit>.t4(
+                            TextDocumentEdit.fromJson(item as Map<String, Object?>))
+                        : (throw '''$item was not one of (CreateFile, DeleteFile, RenameFile, TextDocumentEdit)''')))))
+        .toList();
     return WorkspaceEdit(
       changeAnnotations: changeAnnotations,
       changes: changes,
@@ -44324,9 +44320,8 @@ class WorkspaceEdit implements ToJsonable {
   /// If a client neither supports `documentChanges` nor
   /// `workspace.workspaceEdit.resourceOperations` then only plain `TextEdit`s
   /// using the `changes` property are supported.
-  final Either2<
-      List<Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit>>,
-      List<TextDocumentEdit>>? documentChanges;
+  final List<Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit>>?
+      documentChanges;
 
   Map<String, Object?> toJson() {
     var __result = <String, Object?>{};
@@ -44379,17 +44374,14 @@ class WorkspaceEdit implements ToJsonable {
       try {
         final documentChanges = obj['documentChanges'];
         if (documentChanges != null &&
-            !(((documentChanges is List<Object?> &&
-                    (documentChanges.every((item) =>
-                        (CreateFile.canParse(item, reporter) ||
-                            DeleteFile.canParse(item, reporter) ||
-                            RenameFile.canParse(item, reporter) ||
-                            TextDocumentEdit.canParse(item, reporter))))) ||
-                (documentChanges is List<Object?> &&
-                    (documentChanges.every((item) =>
+            !((documentChanges is List<Object?> &&
+                (documentChanges.every((item) =>
+                    (CreateFile.canParse(item, reporter) ||
+                        DeleteFile.canParse(item, reporter) ||
+                        RenameFile.canParse(item, reporter) ||
                         TextDocumentEdit.canParse(item, reporter))))))) {
           reporter.reportError(
-              'must be of type Either2<List<Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit>>, List<TextDocumentEdit>>');
+              'must be of type List<Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit>>');
           return false;
         }
       } finally {
@@ -44412,7 +44404,14 @@ class WorkspaceEdit implements ToJsonable {
               other.changes,
               (List<TextEdit> a, List<TextEdit> b) =>
                   listEqual(a, b, (TextEdit a, TextEdit b) => a == b)) &&
-          documentChanges == other.documentChanges &&
+          listEqual(
+              documentChanges,
+              other.documentChanges,
+              (Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit> a,
+                      Either4<CreateFile, DeleteFile, RenameFile,
+                              TextDocumentEdit>
+                          b) =>
+                  a == b) &&
           true;
     }
     return false;
@@ -44422,7 +44421,7 @@ class WorkspaceEdit implements ToJsonable {
   int get hashCode => Object.hash(
         lspHashCode(changeAnnotations),
         lspHashCode(changes),
-        documentChanges,
+        lspHashCode(documentChanges),
       );
 
   @override
diff --git a/pkg/analysis_server/lib/src/lsp/mapping.dart b/pkg/analysis_server/lib/src/lsp/mapping.dart
index ff0fc5e5be2..9e0fef26233 100644
--- a/pkg/analysis_server/lib/src/lsp/mapping.dart
+++ b/pkg/analysis_server/lib/src/lsp/mapping.dart
@@ -105,10 +105,7 @@ WorkspaceEdit createRenameEdit(String oldPath, String newPath) {
 
   changes.add(renameUnion);
 
-  final edit = WorkspaceEdit(
-      documentChanges: Either2<
-          List<Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit>>,
-          List<TextDocumentEdit>>.t1(changes));
+  final edit = WorkspaceEdit(documentChanges: changes);
   return edit;
 }
 
@@ -171,15 +168,8 @@ lsp.WorkspaceEdit createWorkspaceEdit(
   final textDocumentEditsAsUnion = Either4<lsp.CreateFile, lsp.DeleteFile,
       lsp.RenameFile, lsp.TextDocumentEdit>.t4(textDocumentEdit);
 
-  // Convert to the union that documentChanges is.
-  final documentChanges = Either2<
-      List<
-          Either4<lsp.CreateFile, lsp.DeleteFile, lsp.RenameFile,
-              lsp.TextDocumentEdit>>,
-      List<lsp.TextDocumentEdit>>.t1([textDocumentEditsAsUnion]);
-
   /// Add the textDocumentEdit to a WorkspaceEdit.
-  return lsp.WorkspaceEdit(documentChanges: documentChanges);
+  return lsp.WorkspaceEdit(documentChanges: [textDocumentEditsAsUnion]);
 }
 
 lsp.CompletionItemKind? declarationKindToCompletionItemKind(
@@ -696,19 +686,10 @@ WorkspaceEdit mergeWorkspaceEdits(List<WorkspaceEdit> edits) {
       <Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit>>[];
 
   for (final edit in edits) {
-    // Flatten the Either into just the Union side to get a flat list.
-    final flatResourceChanges = edit.documentChanges!.map(
-      (resources) => resources,
-      (edits) => edits.map((e) =>
-          Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit>.t4(e)),
-    );
-    changes.addAll(flatResourceChanges);
+    changes.addAll(edit.documentChanges!);
   }
 
-  return WorkspaceEdit(
-      documentChanges: Either2<
-          List<Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit>>,
-          List<TextDocumentEdit>>.t1(changes));
+  return WorkspaceEdit(documentChanges: changes);
 }
 
 lsp.Location navigationTargetToLocation(
@@ -1612,12 +1593,7 @@ lsp.WorkspaceEdit toWorkspaceEdit(
       changes.add(textDocEditUnion);
     }
 
-    return lsp.WorkspaceEdit(
-        documentChanges: Either2<
-            List<
-                Either4<lsp.CreateFile, lsp.DeleteFile, lsp.RenameFile,
-                    lsp.TextDocumentEdit>>,
-            List<lsp.TextDocumentEdit>>.t1(changes));
+    return lsp.WorkspaceEdit(documentChanges: changes);
   } else {
     return lsp.WorkspaceEdit(changes: toWorkspaceEditChanges(edits));
   }
diff --git a/pkg/analysis_server/test/lsp/code_actions_assists_test.dart b/pkg/analysis_server/test/lsp/code_actions_assists_test.dart
index ad18e280d32..efe98865455 100644
--- a/pkg/analysis_server/test/lsp/code_actions_assists_test.dart
+++ b/pkg/analysis_server/test/lsp/code_actions_assists_test.dart
@@ -548,28 +548,20 @@ void f() {
   }
 
   List<TextDocumentEdit> _extractTextDocumentEdits(
-          Either2<
-                  List<
-                      Either4<CreateFile, DeleteFile, RenameFile,
-                          TextDocumentEdit>>,
-                  List<TextDocumentEdit>>
+          List<Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit>>
               documentChanges) =>
-      documentChanges.map(
-        // Extract TextDocumentEdits from union of resource changes
-        (changes) => changes
-            .map(
-              (change) => change.map(
-                (create) => null,
-                (delete) => null,
-                (rename) => null,
-                (textDocEdit) => textDocEdit,
-              ),
-            )
-            .whereNotNull()
-            .toList(),
-        // Already TextDocumentEdits
-        (edits) => edits,
-      );
+      // Extract TextDocumentEdits from union of resource changes
+      documentChanges
+          .map(
+            (change) => change.map(
+              (create) => null,
+              (delete) => null,
+              (rename) => null,
+              (textDocEdit) => textDocEdit,
+            ),
+          )
+          .whereNotNull()
+          .toList();
 }
 
 class _RawParams extends ToJsonable {
diff --git a/pkg/analysis_server/test/lsp/server_abstract.dart b/pkg/analysis_server/test/lsp/server_abstract.dart
index 273369b947d..c19d82ecc85 100644
--- a/pkg/analysis_server/test/lsp/server_abstract.dart
+++ b/pkg/analysis_server/test/lsp/server_abstract.dart
@@ -684,8 +684,7 @@ mixin LspAnalysisServerTestMixin implements ClientCapabilitiesHelperMixin {
 
   void applyDocumentChanges(
     Map<String, String> fileContents,
-    Either2<List<Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit>>,
-            List<TextDocumentEdit>>
+    List<Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit>>
         documentChanges, {
     Map<String, int>? expectedVersions,
   }) {
@@ -694,10 +693,7 @@ mixin LspAnalysisServerTestMixin implements ClientCapabilitiesHelperMixin {
     if (expectedVersions != null) {
       expectDocumentVersions(documentChanges, expectedVersions);
     }
-    documentChanges.map(
-      (changes) => applyResourceChanges(fileContents, changes),
-      (edits) => applyTextDocumentEdits(fileContents, edits),
-    );
+    applyResourceChanges(fileContents, documentChanges);
   }
 
   void applyResourceChanges(
@@ -904,31 +900,20 @@ mixin LspAnalysisServerTestMixin implements ClientCapabilitiesHelperMixin {
   /// Validates the document versions for a set of edits match the versions in
   /// the supplied map.
   void expectDocumentVersions(
-    Either2<List<Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit>>,
-            List<TextDocumentEdit>>
+    List<Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit>>
         documentChanges,
     Map<String, int> expectedVersions,
   ) {
-    documentChanges.map(
-      // For resource changes, we only need to validate changes since
-      // creates/renames/deletes do not supply versions.
-      (changes) {
-        for (var change in changes) {
-          change.map(
-            (create) => {},
-            (delete) {},
-            (rename) {},
-            (edit) => expectDocumentVersion(edit, expectedVersions),
-          );
-        }
-      },
-      // Validate versions on simple doc edits
-      (edits) {
-        for (var edit in edits) {
-          expectDocumentVersion(edit, expectedVersions);
-        }
-      },
-    );
+    // For resource changes, we only need to validate changes since
+    // creates/renames/deletes do not supply versions.
+    for (var change in documentChanges) {
+      change.map(
+        (create) {},
+        (delete) {},
+        (rename) {},
+        (edit) => expectDocumentVersion(edit, expectedVersions),
+      );
+    }
   }
 
   Future<ShowMessageParams> expectErrorNotification(
diff --git a/pkg/analysis_server/test/tool/lsp_spec/json_test.dart b/pkg/analysis_server/test/tool/lsp_spec/json_test.dart
index 52a685967c0..1af098aad31 100644
--- a/pkg/analysis_server/test/tool/lsp_spec/json_test.dart
+++ b/pkg/analysis_server/test/tool/lsp_spec/json_test.dart
@@ -306,7 +306,7 @@ void main() {
       expect(
           reporter.errors.first,
           equals(
-              'params.documentChanges must be of type Either2<List<Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit>>, List<TextDocumentEdit>>'));
+              'params.documentChanges must be of type List<Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit>>'));
     });
 
     test('ResponseMessage can include a null result', () {
diff --git a/pkg/analysis_server/tool/lsp_spec/codegen_dart.dart b/pkg/analysis_server/tool/lsp_spec/codegen_dart.dart
index e2463db5ba2..50297165279 100644
--- a/pkg/analysis_server/tool/lsp_spec/codegen_dart.dart
+++ b/pkg/analysis_server/tool/lsp_spec/codegen_dart.dart
@@ -420,7 +420,7 @@ void _writeEnumClass(IndentableStringBuffer buffer, Namespace namespace) {
       resolveTypeAlias(requiredValueType, resolveEnumClasses: true);
 
   buffer
-    ..writeln('class ${namespace.name} {')
+    ..writeln('class ${namespace.name} implements ToJsonable {')
     ..indent()
     ..writeIndentedln('const ${namespace.name}$constructorName(this._value);')
     ..writeIndentedln('const ${namespace.name}.fromJson(this._value);')
diff --git a/pkg/analysis_server/tool/lsp_spec/typescript_parser.dart b/pkg/analysis_server/tool/lsp_spec/typescript_parser.dart
index e4415a8ef52..309deb4bb2a 100644
--- a/pkg/analysis_server/tool/lsp_spec/typescript_parser.dart
+++ b/pkg/analysis_server/tool/lsp_spec/typescript_parser.dart
@@ -531,6 +531,18 @@ class Parser {
       return uniqueTypes.firstWhere(isAnyType);
     }
 
+    // Special case to simplify a complex type in the TypeScript spec that is
+    // hard to detect generically and is already simplified in the JSON model.
+    // The first type in the union is fully representable in the second and can
+    // be dropped.
+    // TODO(dantup): Remove this when switching to the JSON model.
+    if (uniqueTypes.length == 2 &&
+        uniqueTypes[0].dartTypeWithTypeArgs == 'List<TextDocumentEdit>' &&
+        uniqueTypes[1].dartTypeWithTypeArgs ==
+            'List<Either4<CreateFile, DeleteFile, RenameFile, TextDocumentEdit>>') {
+      return uniqueTypes[1];
+    }
+
     return uniqueTypes.length == 1
         ? uniqueTypes.single
         : uniqueTypes.every(isLiteralType)