Make sure to invoke capability handlers

Author: mattmassicotte

Package.resolved

@@ -17,7 +17,7 @@ let package = Package(
 			targets: ["LanguageClient"]),
 	],
 	dependencies: [
-		.package(url: "https://github.com/ChimeHQ/LanguageServerProtocol", from: "0.13.2"),
+		.package(url: "https://github.com/ChimeHQ/LanguageServerProtocol", from: "0.13.3"),
 		.package(url: "https://github.com/Frizlab/FSEventsWrapper", from: "2.1.0"),
 		.package(url: "https://github.com/davbeck/swift-glob", from: "0.0.0"),
 		.package(url: "https://github.com/ChimeHQ/JSONRPC", from: "0.9.0"),

Package.swift

@@ -42,6 +42,7 @@ extension DataChannel {
 			let dataStream = stdoutPipe.fileHandleForReading.dataStream
 
 			for try await data in dataStream {
+				print("read:", String(decoding: data, as: UTF8.self))
 				continuation.yield(data)
 			}
 
@@ -61,6 +62,8 @@ extension DataChannel {
 			// to prevent it from being deallocated
 			_ = process
 
+			print("write:", String(decoding: $0, as: UTF8.self))
+
 			try stdinPipe.fileHandleForWriting.write(contentsOf: $0)
 		}
 

Sources/LanguageClient/DataChannel+LocalProcess.swift

@@ -3,15 +3,22 @@ import Foundation
 import os.log
 #endif
 
-import Semaphore
+import JSONRPC
 import LanguageServerProtocol
+import Semaphore
 
 enum InitializingServerError: Error {
 	case noStateProvider
 	case capabilitiesUnavailable
 	case stateInvalid
 }
 
+extension AnyJSONRPCResponseError {
+	init(error: any Error) {
+		self.init(code: JSONRPCErrors.internalError, message: error.localizedDescription)
+	}
+}
+
 /// Server implementation that lazily initializes another Server on first message.
 ///
 /// Provides special handling for `shutdown` and `exit` messages.
@@ -205,33 +212,47 @@ extension InitializingServer {
 		return initResponse
 	}
 
-	private func handleEvent(_ event: ServerEvent) {
+	private func handleEvent(_ event: ServerEvent) async {
 		switch event {
 		case let .request(_, request):
-			handleRequest(request)
+			await handleRequest(request)
 		default:
 			break
 		}
 	}
 
-	private func handleRequest(_ request: ServerRequest) {
+	private func handleRequest(_ request: ServerRequest) async {
 		guard case .initialized(let initResp) = self.state else {
 			fatalError("received a request without being initialized")
 		}
 
 		var newCaps = initResp.capabilities
 
-		do {
-			switch request {
-			case .clientRegisterCapability(let params, _):
+		switch request {
+		case let .clientRegisterCapability(params, handler):
+			do {
 				try newCaps.applyRegistrations(params.registrations)
-			case .clientUnregisterCapability(let params, _):
+
+				await handler(nil)
+			} catch {
+				print("failed to process clientRegisterCapability: \(error)")
+
+				await handler(AnyJSONRPCResponseError(error: error))
+			}
+		case let .clientUnregisterCapability(params, handler):
+			do {
 				try newCaps.applyUnregistrations(params.unregistrations)
-			default:
-				break
+
+				await handler(nil)
+			} catch {
+				print("failed to process clientUnregisterCapability: \(error)")
+
+				await handler(AnyJSONRPCResponseError(error: error))
 			}
-		} catch {
-			print("unable to mutate server capabilities: \(error)")
+		default:
+			print("unhandled request: \(request)")
+
+			await request.relyWithError(InitializingServerError.stateInvalid)
 		}
 
 		if initResp.capabilities != newCaps {

Sources/LanguageClient/InitializingServer.swift

@@ -78,11 +78,14 @@ final class ServerTests: XCTestCase {
 			Registration(id: "abc", method: ClientRequest.Method.textDocumentSemanticTokens.rawValue, registerOptions: options)
 		])
 
-		await mockChannel.sendMockRequest(.clientRegisterCapability(params, { _ in }))
+		let registerExp = expectation(description: "registration handled")
+		await mockChannel.sendMockRequest(.clientRegisterCapability(params, { _ in registerExp.fulfill() }))
 
 		let caps2 = await iterator.next()
 
 		XCTAssertNotNil(caps2?.semanticTokensProvider)
+
+		await fulfillment(of: [registerExp], timeout: 1.0)
 	}
 }
 #endif