support for textDocument/prepareTypeHierarchy

README.md

@@ -100,7 +100,7 @@ The LSP [specification](https://microsoft.github.io/language-server-protocol/spe
 | textDocument/onTypeFormatting | ✅ |
 | textDocument/prepareCallHierarchy | ✅ |
 | textDocument/prepareRename | ✅ |
-| textDocument/prepareTypeHierarchy | - |
+| textDocument/prepareTypeHierarchy | ✅ |
 | textDocument/publishDiagnostics | ✅ |
 | textDocument/rangeFormatting | ✅ |
 | textDocument/references | ✅  |

Sources/LSPClient/Client.JSONRPCServerConnection.swift

@@ -145,6 +145,8 @@ public actor JSONRPCServerConnection: ServerConnection {
 			return try await session.response(to: method, params: params)
 		case .prepareRename(let params, _):
 			return try await session.response(to: method, params: params)
+		case .prepareTypeHierarchy(let params, _):
+			return try await session.response(to: method, params: params)
 		case .rename(let params, _):
 			return try await session.response(to: method, params: params)
 		case .inlayHint(let params, _):

Sources/LSPClient/Client.ServerConnection.swift

@@ -145,6 +145,10 @@ public extension ServerConnection {
         try await sendRequest(.prepareRename(params, ClientRequest.NullHandler))
     }
 
+	func prepareTypeHeirarchy(params: TypeHierarchyPrepareParams) async throws -> PrepareTypeHeirarchyResponse {
+		try await sendRequest(.prepareTypeHierarchy(params, ClientRequest.NullHandler))
+	}
+
     func rename(params: RenameParams) async throws -> RenameResponse {
         try await sendRequest(.rename(params, ClientRequest.NullHandler))
     }

Sources/LSPServer/Server.JSONRPCClientConnection.swift

@@ -226,6 +226,8 @@ public actor JSONRPCClientConnection : ClientConnection {
 				yield(id: id, request: ClientRequest.prepareCallHierarchy(try decodeRequestParams(data), makeHandler(handler)))
 			case .textDocumentPrepareRename:
 				yield(id: id, request: ClientRequest.prepareRename(try decodeRequestParams(data), makeHandler(handler)))
+			case .textDocumentPrepareTypeHierarchy:
+				yield(id: id, request: ClientRequest.prepareTypeHierarchy(try decodeRequestParams(data), makeHandler(handler)))
 			case .textDocumentRename:
 				yield(id: id, request: ClientRequest.rename(try decodeRequestParams(data), makeHandler(handler)))
 			case .textDocumentInlayHint:

Sources/LSPServer/Server.RequestHandler.swift

@@ -37,6 +37,7 @@ public protocol RequestHandler : ErrorHandler {
 	func linkedEditingRange(id: JSONId, params: LinkedEditingRangeParams) async -> Result<LinkedEditingRangeResponse, AnyJSONRPCResponseError>
 	func prepareCallHierarchy(id: JSONId, params: CallHierarchyPrepareParams) async -> Result<CallHierarchyPrepareResponse, AnyJSONRPCResponseError>
 	func prepareRename(id: JSONId, params: PrepareRenameParams) async -> Result<PrepareRenameResponse, AnyJSONRPCResponseError>
+	func prepareTypeHeirarchy(id: JSONId, params: TypeHierarchyPrepareParams) async -> Result<PrepareTypeHeirarchyResponse, AnyJSONRPCResponseError>
 	func rename(id: JSONId, params: RenameParams) async -> Result<RenameResponse, AnyJSONRPCResponseError>
 	func documentLink(id: JSONId, params: DocumentLinkParams) async -> Result<DocumentLinkResponse, AnyJSONRPCResponseError>
 	func documentLinkResolve(id: JSONId, params: DocumentLink) async -> Result<DocumentLink, AnyJSONRPCResponseError>
@@ -125,6 +126,8 @@ public extension RequestHandler {
 			await handler(await prepareCallHierarchy(id: id, params: params))
 		case let .prepareRename(params, handler):
 			await handler(await prepareRename(id: id, params: params))
+		case let .prepareTypeHierarchy(params, handler):
+			await handler(await prepareTypeHeirarchy(id: id, params: params))
 		case let .rename(params, handler):
 			await handler(await rename(id: id, params: params))
 		case let .inlayHint(params, handler):
@@ -203,6 +206,7 @@ public extension RequestHandler {
 	func linkedEditingRange(id: JSONId, params: LinkedEditingRangeParams) async -> Result<LinkedEditingRangeResponse, AnyJSONRPCResponseError> { .failure(NotImplementedError) }
 	func prepareCallHierarchy(id: JSONId, params: CallHierarchyPrepareParams) async -> Result<CallHierarchyPrepareResponse, AnyJSONRPCResponseError> { .failure(NotImplementedError) }
 	func prepareRename(id: JSONId, params: PrepareRenameParams) async -> Result<PrepareRenameResponse, AnyJSONRPCResponseError> { .failure(NotImplementedError) }
+	func prepareTypeHeirarchy(id: JSONId, params: TypeHierarchyPrepareParams) async -> Result<PrepareTypeHeirarchyResponse, AnyJSONRPCResponseError> { .failure(NotImplementedError) }
 	func rename(id: JSONId, params: RenameParams) async -> Result<RenameResponse, AnyJSONRPCResponseError> { .failure(NotImplementedError) }
 	func inlayHint(id: JSONId, params: InlayHintParams) async -> Result<InlayHintResponse, AnyJSONRPCResponseError> { .failure(NotImplementedError) }
 	func inlayHintResolve(id: JSONId, params: InlayHint) async -> Result<InlayHintResponse, AnyJSONRPCResponseError> { .failure(NotImplementedError) }

Sources/LanguageServerProtocol/LanguageFeatures/TypeHeirarchy.swift

@@ -0,0 +1,26 @@
+import Foundation
+
+public struct TypeHierarchyPrepareParams: Codable, Hashable, Sendable {
+	public let textDocument: TextDocumentIdentifier
+	public let position: Position
+	public let workDoneToken: ProgressToken?
+
+	public init(textDocument: TextDocumentIdentifier, position: Position, workDoneToken: ProgressToken? = nil) {
+		self.textDocument = textDocument
+		self.position = position
+		self.workDoneToken = workDoneToken
+	}
+}
+
+public struct TypeHierarchyItem: Codable, Hashable, Sendable {
+	public let name: String
+	public let kind: SymbolKind
+	public let tags: [SymbolTag]?
+	public let detail: String?
+	public let uri: DocumentUri
+	public let range: LSPRange
+	public let selectionRange: LSPRange
+	public let data: LSPAny?
+}
+
+public typealias PrepareTypeHeirarchyResponse = [TypeHierarchyItem]?

Sources/LanguageServerProtocol/LanguageServerProtocol.swift

@@ -140,6 +140,7 @@ public enum ClientRequest: Sendable {
         case textDocumentSignatureHelp = "textDocument/signatureHelp"
         case textDocumentDeclaration = "textDocument/declaration"
         case textDocumentDefinition = "textDocument/definition"
+		case textDocumentPrepareTypeHierarchy = "textDocument/prepareTypeHierarchy"
         case textDocumentTypeDefinition = "textDocument/typeDefinition"
         case textDocumentImplementation = "textDocument/implementation"
         case textDocumentReferences = "textDocument/references"
@@ -204,6 +205,7 @@ public enum ClientRequest: Sendable {
 	case linkedEditingRange(LinkedEditingRangeParams, Handler<LinkedEditingRangeResponse>)
 	case prepareCallHierarchy(CallHierarchyPrepareParams, Handler<CallHierarchyPrepareResponse>)
 	case prepareRename(PrepareRenameParams, Handler<PrepareRenameResponse>)
+	case prepareTypeHierarchy(TypeHierarchyPrepareParams, Handler<PrepareTypeHeirarchyResponse>)
 	case rename(RenameParams, Handler<RenameResponse>)
 	case inlayHint(InlayHintParams, Handler<InlayHintResponse>)
 	case inlayHintResolve(InlayHint, Handler<InlayHintResponse>)
@@ -282,6 +284,8 @@ public enum ClientRequest: Sendable {
 			return .textDocumentPrepareCallHierarchy
         case .prepareRename:
             return .textDocumentPrepareRename
+		case .prepareTypeHierarchy:
+			return .textDocumentPrepareTypeHierarchy
         case .rename:
             return .textDocumentRename
 		case .inlayHint: