Initial draft of a custom LSP protocol for refactoring

Change-Id: Ib7a6b6bd0b2e0dccd8e7b6c117dc284b0e5a95cd
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/253361
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>
Reviewed-by: Phil Quitslund <pquitslund@google.com>
Reviewed-by: Danny Tuppeny <danny@tuppeny.com>

pkg/analysis_server/lib/lsp_protocol/protocol_custom_generated.dart

@@ -136,6 +136,130 @@ class ClosingLabel implements ToJsonable {
   String toString() => jsonEncoder.convert(toJson());
 }
 
+/// Information about one of the arguments needed by the command.
+///
+/// A list of parameters is sent in the `data` field of the `CodeAction`
+/// returned by the server. The values of the parameters should appear in the
+/// `args` field of the `Command` sent to the server in the same order as the
+/// corresponding parameters.
+class CommandParameter implements ToJsonable {
+  static const jsonHandler = LspJsonHandler(
+    CommandParameter.canParse,
+    CommandParameter.fromJson,
+  );
+
+  CommandParameter({
+    required this.defaultValue,
+    required this.label,
+    required this.type,
+  });
+  static CommandParameter fromJson(Map<String, Object?> json) {
+    final defaultValueJson = json['defaultValue'];
+    final defaultValue = defaultValueJson as String;
+    final labelJson = json['label'];
+    final label = labelJson as String;
+    final typeJson = json['type'];
+    final type = CommandParameterType.fromJson(typeJson as String);
+    return CommandParameter(
+      defaultValue: defaultValue,
+      label: label,
+      type: type,
+    );
+  }
+
+  /// The default value for the parameter.
+  final String defaultValue;
+
+  /// A human-readable label to be displayed in the UI affordance used to prompt
+  /// the user for the value of the parameter.
+  final String label;
+
+  /// The type of the value of the parameter.
+  final CommandParameterType type;
+
+  @override
+  Map<String, Object?> toJson() {
+    var result = <String, Object?>{};
+    result['defaultValue'] = defaultValue;
+    result['label'] = label;
+    result['type'] = type.toJson();
+    return result;
+  }
+
+  static bool canParse(Object? obj, LspJsonReporter reporter) {
+    if (obj is Map<String, Object?>) {
+      if (!_canParseString(obj, reporter, 'defaultValue',
+          allowsUndefined: false, allowsNull: false)) {
+        return false;
+      }
+      if (!_canParseString(obj, reporter, 'label',
+          allowsUndefined: false, allowsNull: false)) {
+        return false;
+      }
+      return _canParseCommandParameterType(obj, reporter, 'type',
+          allowsUndefined: false, allowsNull: false);
+    } else {
+      reporter.reportError('must be of type CommandParameter');
+      return false;
+    }
+  }
+
+  @override
+  bool operator ==(Object other) {
+    return other is CommandParameter &&
+        other.runtimeType == CommandParameter &&
+        defaultValue == other.defaultValue &&
+        label == other.label &&
+        type == other.type;
+  }
+
+  @override
+  int get hashCode => Object.hash(
+        defaultValue,
+        label,
+        type,
+      );
+
+  @override
+  String toString() => jsonEncoder.convert(toJson());
+}
+
+/// The type of the value associated with a CommandParameter. All values are
+/// encoded as strings, but the type indicates how the string will be decoded by
+/// the server.
+class CommandParameterType implements ToJsonable {
+  const CommandParameterType(this._value);
+  const CommandParameterType.fromJson(this._value);
+
+  final String _value;
+
+  static bool canParse(Object? obj, LspJsonReporter reporter) => obj is String;
+
+  /// The type associated with a bool value.
+  ///
+  /// The value must either be `'true'` or `'false'`.
+  static const boolean = CommandParameterType('boolean');
+
+  /// The type associated with a value representing a path to a file.
+  static const filePath = CommandParameterType('filePath');
+
+  /// The type associated with a string value.
+  static const string = CommandParameterType('string');
+
+  @override
+  Object toJson() => _value;
+
+  @override
+  String toString() => _value.toString();
+
+  @override
+  int get hashCode => _value.hashCode;
+
+  @override
+  bool operator ==(Object other) =>
+      other is CommandParameterType && other._value == _value;
+}
+
 class CompletionItemResolutionInfo implements ToJsonable {
   static const jsonHandler = LspJsonHandler(
     CompletionItemResolutionInfo.canParse,
@@ -1811,6 +1935,32 @@ bool _canParseBool(
   return true;
 }
 
+bool _canParseCommandParameterType(
+    Map<String, Object?> map, LspJsonReporter reporter, String fieldName,
+    {required bool allowsUndefined, required bool allowsNull}) {
+  reporter.push(fieldName);
+  try {
+    if (!allowsUndefined && !map.containsKey(fieldName)) {
+      reporter.reportError('must not be undefined');
+      return false;
+    }
+    final value = map[fieldName];
+    final nullCheck = allowsNull || allowsUndefined;
+    if (!nullCheck && value == null) {
+      reporter.reportError('must not be null');
+      return false;
+    }
+    if ((!nullCheck || value != null) &&
+        !CommandParameterType.canParse(value, reporter)) {
+      reporter.reportError('must be of type CommandParameterType');
+      return false;
+    }
+  } finally {
+    reporter.pop();
+  }
+  return true;
+}
+
 bool _canParseElement(
     Map<String, Object?> map, LspJsonReporter reporter, String fieldName,
     {required bool allowsUndefined, required bool allowsNull}) {

pkg/analysis_server/lib/lsp_protocol/protocol_generated.dart

@@ -306,7 +306,7 @@ typedef TextDocumentSignatureHelpResult = SignatureHelp?;
 
 /// Result for a request to resolve the type definition locations of a symbol at
 /// a given text document position. The request's parameter is of type
-/// TextDocumentPositionParams the response is of type Definition or a Thenable
+/// TextDocumentPositioParams the response is of type Definition or a Thenable
 /// that resolves to such.
 typedef TextDocumentTypeDefinitionResult
     = Either2<Definition, List<DefinitionLink>>?;
@@ -21955,7 +21955,7 @@ class PreviousResultId implements ToJsonable {
     );
   }
 
-  /// The URI for which the client knows a result id.
+  /// The URI for which the client knowns a result id.
   final DocumentUri uri;
 
   /// The value of the previous result id.

pkg/analysis_server/tool/lsp_spec/generate_all.dart

@@ -111,9 +111,11 @@ const jsonEncoder = JsonEncoder.withIndent('    ');
 
 List<LspEntity> getCustomClasses() {
   /// Helper to create an interface type.
-  Interface interface(String name, List<Member> fields, {String? baseType}) {
+  Interface interface(String name, List<Member> fields,
+      {String? baseType, String? comment}) {
     return Interface(
       name: name,
+      comment: comment,
       baseTypes: [if (baseType != null) TypeReference(baseType)],
       members: fields,
     );
@@ -353,7 +355,68 @@ List<LspEntity> getCustomClasses() {
         ]),
       ),
       isRename: false,
-    )
+    ),
+    //
+    // Command parameter support
+    //
+    interface(
+      'CommandParameter',
+      [
+        field(
+          'label',
+          type: 'String',
+          comment:
+              'A human-readable label to be displayed in the UI affordance '
+              'used to prompt the user for the value of the parameter.',
+        ),
+        field(
+          'type',
+          type: 'CommandParameterType',
+          comment: 'The type of the value of the parameter.',
+        ),
+        field(
+          'defaultValue',
+          type: 'String',
+          comment: 'The default value for the parameter.',
+        ),
+      ],
+      comment: 'Information about one of the arguments needed by the command.'
+          '\n\n'
+          'A list of parameters is sent in the `data` field of the '
+          '`CodeAction` returned by the server. The values of the parameters '
+          'should appear in the `args` field of the `Command` sent to the '
+          'server in the same order as the corresponding parameters.',
+    ),
+    LspEnum(
+      name: 'CommandParameterType',
+      comment: 'The type of the value associated with a CommandParameter. All '
+          'values are encoded as strings, but the type indicates how the '
+          'string will be decoded by the server.',
+      members: [
+        Constant(
+          name: 'boolean',
+          value: 'boolean',
+          type: TypeReference('String'),
+          comment: 'The type associated with a bool value.'
+              '\n\n'
+              "The value must either be `'true'` or `'false'`.",
+        ),
+        Constant(
+          name: 'string',
+          value: 'string',
+          type: TypeReference('String'),
+          comment: 'The type associated with a string value.',
+        ),
+        Constant(
+          name: 'filePath',
+          value: 'filePath',
+          type: TypeReference('String'),
+          comment:
+              'The type associated with a value representing a path to a file.',
+        ),
+      ],
+      typeOfValues: TypeReference('String'),
+    ),
   ];
   return customTypes;
 }