clean up code

Author: devcrocod

src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/client/Client.kt

@@ -59,7 +59,7 @@ public class ClientOptions(
  * An MCP client on top of a pluggable transport.
  *
  * The client automatically performs the initialization handshake with the server when [connect] is called.
- * After initialization, [severCapabilities] and [serverVersion] provide details about the connected server.
+ * After initialization, [serverCapabilities] and [serverVersion] provide details about the connected server.
  *
  * You can extend this class with custom request/notification/result types if needed.
  *
@@ -167,9 +167,7 @@ public open class Client(
             Method.Defined.ResourcesUnsubscribe,
                 -> {
                 val resCaps = serverCapabilities?.resources
-                if (resCaps == null) {
-                    throw IllegalStateException("Server does not support resources (required for $method)")
-                }
+                    ?: error("Server does not support resources (required for $method)")
 
                 if (method == Method.Defined.ResourcesSubscribe && resCaps.subscribe != true) {
                     throw IllegalStateException(

src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/client/SSEClientTransport.kt

@@ -59,7 +59,7 @@ public class SseClientTransport(
     }
 
     override suspend fun start() {
-        if (!initialized.compareAndSet(false, true)) {
+        if (!initialized.compareAndSet(expectedValue = false, newValue = true)) {
             error(
                 "SSEClientTransport already started! " +
                         "If using Client class, note that connect() calls start() automatically.",

src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/server/SSEServerTransport.kt

@@ -45,7 +45,7 @@ public class SseServerTransport(
      */
     override suspend fun start() {
         if (!initialized.compareAndSet(expectedValue = false, newValue = true)) {
-            throw error("SSEServerTransport already started! If using Server class, note that connect() calls start() automatically.")
+            error("SSEServerTransport already started! If using Server class, note that connect() calls start() automatically.")
         }
 
         // Send the endpoint event
@@ -117,7 +117,7 @@ public class SseServerTransport(
 
     override suspend fun send(message: JSONRPCMessage) {
         if (!initialized.load()) {
-            throw error("Not connected")
+            error("Not connected")
         }
 
         session.send(

src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/server/StdioServerTransport.kt

@@ -8,10 +8,13 @@ import io.modelcontextprotocol.kotlin.sdk.shared.ReadBuffer
 import io.modelcontextprotocol.kotlin.sdk.shared.serializeMessage
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Job
+import kotlinx.coroutines.NonCancellable
 import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.cancelAndJoin
 import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.isActive
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 import kotlinx.io.Buffer
 import kotlinx.io.Sink
 import kotlinx.io.Source
@@ -123,15 +126,26 @@ public class StdioServerTransport(
     override suspend fun close() {
         if (!initialized.compareAndSet(expectedValue = true, newValue = false)) return
 
-        // Cancel reading job and close channel
-        readingJob?.cancel() // ToDO("was cancel and join")
-        sendingJob?.cancel()
+        withContext(NonCancellable) {
+            writeChannel.close()
+            sendingJob?.cancelAndJoin()
 
-        readChannel.close()
-        writeChannel.close()
-        readBuffer.clear()
+            runCatching {
+                inputStream.close()
+            }.onFailure { logger.warn(it) { "Failed to close stdin" } }
 
-        _onClose.invoke()
+            readingJob?.cancel()
+
+            readChannel.close()
+            readBuffer.clear()
+
+            runCatching {
+                outputWriter.flush()
+                outputWriter.close()
+            }.onFailure { logger.warn(it) { "Failed to close stdout" } }
+
+            _onClose.invoke()
+        }
     }
 
     override suspend fun send(message: JSONRPCMessage) {

src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/shared/Protocol.kt

@@ -69,7 +69,8 @@ public open class ProtocolOptions(
      * considered a logic error to mis-specify those.
      *
      * Currently, this defaults to false, for backwards compatibility with SDK versions
-     * that did not advertise capabilities correctly. In future, this will default to true.
+     * that did not advertise capabilities correctly.
+     * In the future, this will default to true.
      */
     public var enforceStrictCapabilities: Boolean = false,
 
@@ -140,7 +141,8 @@ public abstract class Protocol(
     /**
      * Callback for when an error occurs.
      *
-     * Note that errors are not necessarily fatal they are used for reporting any kind of exceptional condition out of band.
+     * Note that errors are not necessarily fatal they are used
+     * for reporting any kind of exceptional condition out of a band.
      */
     public open fun onError(error: Throwable) {}
 

src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/shared/Transport.kt

@@ -4,7 +4,7 @@ import io.modelcontextprotocol.kotlin.sdk.JSONRPCMessage
 import kotlinx.coroutines.CompletableDeferred
 
 /**
- * Describes the minimal contract for a MCP transport that a client or server can communicate over.
+ * Describes the minimal contract for MCP transport that a client or server can communicate over.
  */
 public interface Transport {
     /**
@@ -38,7 +38,7 @@ public interface Transport {
      * Callback for when an error occurs.
      *
      * Note that errors are not necessarily fatal; they are used for reporting any kind of
-     * exceptional condition out of band.
+     * exceptional condition out of a band.
      */
     public fun onError(block: (Throwable) -> Unit)
 

src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/shared/WebSocketMcpTransport.kt

@@ -41,7 +41,7 @@ public abstract class WebSocketMcpTransport : AbstractTransport() {
     protected abstract suspend fun initializeSession()
 
     override suspend fun start() {
-        if (!initialized.compareAndSet(false, true)) {
+        if (!initialized.compareAndSet(expectedValue = false, newValue = true)) {
             error(
                 "WebSocketClientTransport already started! " +
                         "If using Client class, note that connect() calls start() automatically.",

src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/types.kt

@@ -183,7 +183,7 @@ internal fun JSONRPCNotification.fromJSON(): Notification {
 public sealed interface RequestResult : WithMeta
 
 /**
- * An empty result for a request, containing optional metadata.
+ * An empty result for a request containing optional metadata.
  *
  * @param _meta Additional metadata for the response. Defaults to an empty JSON object.
  */
@@ -492,7 +492,8 @@ public class InitializedNotification : ClientNotification {
 
 /* Ping */
 /**
- * A ping, issued by either the server or the client, to check that the other party is still alive. The receiver must promptly respond, or else may be disconnected.
+ * A ping, issued by either the server or the client, to check that the other party is still alive.
+ * The receiver must promptly respond, or else it may be disconnected.
  */
 @Serializable
 public class PingRequest : ServerRequest, ClientRequest {

src/commonTest/kotlin/io/modelcontextprotocol/kotlin/sdk/shared/ReadBufferTest.kt

@@ -28,12 +28,12 @@ class ReadBufferTest {
     fun `should only yield a message after a newline`() {
         val readBuffer = ReadBuffer()
 
-        // Append message without newline
+        // Append message without a newline
         val messageBytes = json.encodeToString(testMessage).encodeToByteArray()
         readBuffer.append(messageBytes)
         assertNull(readBuffer.readMessage())
 
-        // Append newline and verify message is now available
+        // Append a newline and verify message is now available
         readBuffer.append("\n".encodeToByteArray())
         assertEquals(testMessage, readBuffer.readMessage())
         assertNull(readBuffer.readMessage())

src/jvmTest/kotlin/client/ClientTest.kt

@@ -486,10 +486,10 @@ class ClientTest {
 
         server.setRequestHandler<ListResourcesRequest>(Method.Defined.ResourcesList) { _, extra ->
             // Simulate a delayed response
-            // Wait ~100ms unless cancelled
+            // Wait ~100ms unless canceled
             try {
                 kotlinx.coroutines.withTimeout(100L) {
-                    // Just delay here, if timeout is 0 on client side this won't return in time
+                    // Just delay here, if timeout is 0 on the client side, this won't return in time
                     kotlinx.coroutines.delay(100)
                 }
             } catch (_: Exception) {