Added the returned serverInstructions to the client and added verification to the ServerTests (addresses PR feedback)

Author: jclyne

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

@@ -91,6 +91,13 @@ public open class Client(private val clientInfo: Implementation, options: Client
     public var serverCapabilities: ServerCapabilities? = null
         private set
 
+    /**
+     * Optional human-readable instructions or description for the client.
+     * This can be used to provide context or usage guidelines for users interacting with the client.
+     */
+    public var serverInstructions: String? = null
+        private set
+
     /**
      * Retrieves the server's reported version information after initialization.
      *
@@ -154,6 +161,7 @@ public open class Client(private val clientInfo: Implementation, options: Client
 
             serverCapabilities = result.capabilities
             serverVersion = result.serverInfo
+            serverInstructions = result.instructions
 
             notification(InitializedNotification())
         } catch (error: Throwable) {

kotlin-sdk-server/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/server/ServerSession.kt

@@ -255,7 +255,7 @@ public open class ServerSession(
 
             Defined.NotificationsResourcesUpdated,
             Defined.NotificationsResourcesListChanged,
-                -> {
+            -> {
                 if (serverCapabilities.resources == null) {
                     throw IllegalStateException(
                         "Server does not support notifying about resources (required for ${method.value})",
@@ -281,7 +281,7 @@ public open class ServerSession(
 
             Defined.NotificationsCancelled,
             Defined.NotificationsProgress,
-                -> {
+            -> {
                 // Always allowed
             }
 
@@ -316,7 +316,7 @@ public open class ServerSession(
 
             Defined.PromptsGet,
             Defined.PromptsList,
-                -> {
+            -> {
                 if (serverCapabilities.prompts == null) {
                     throw IllegalStateException("Server does not support prompts (required for $method)")
                 }
@@ -327,15 +327,15 @@ public open class ServerSession(
             Defined.ResourcesRead,
             Defined.ResourcesSubscribe,
             Defined.ResourcesUnsubscribe,
-                -> {
+            -> {
                 if (serverCapabilities.resources == null) {
                     throw IllegalStateException("Server does not support resources (required for $method)")
                 }
             }
 
             Defined.ToolsCall,
             Defined.ToolsList,
-                -> {
+            -> {
                 if (serverCapabilities.tools == null) {
                     throw IllegalStateException("Server does not support tools (required for $method)")
                 }

kotlin-sdk-test/src/jvmTest/kotlin/io/modelcontextprotocol/kotlin/sdk/server/ServerTest.kt

@@ -19,6 +19,7 @@ import kotlinx.coroutines.CompletableDeferred
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.test.runTest
 import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.assertNull
 import org.junit.jupiter.api.assertThrows
 import kotlin.test.assertEquals
 import kotlin.test.assertFalse
@@ -485,32 +486,15 @@ class ServerTest {
         val (clientTransport, serverTransport) = InMemoryTransport.createLinkedPair()
         val client = Client(clientInfo = Implementation(name = "test client", version = "1.0"))
 
-        launch { client.connect(clientTransport) }
-        launch { server.connect(serverTransport) }
+        server.connect(serverTransport)
+        client.connect(clientTransport)
 
-        // The test passes if the server can be created with instructions without throwing
-        assertTrue(true, "Server should accept instructions parameter")
+        assertEquals(instructions, client.serverInstructions)
     }
 
-    @Test
-    fun `Server constructor should work with null instructions`() = runTest {
-        val serverInfo = Implementation(name = "test server", version = "1.0")
-        val serverOptions = ServerOptions(capabilities = ServerCapabilities())
-
-        val server = Server(serverInfo, serverOptions, null)
-
-        // Test that server works with null instructions
-        val (clientTransport, serverTransport) = InMemoryTransport.createLinkedPair()
-        val client = Client(clientInfo = Implementation(name = "test client", version = "1.0"))
-
-        launch { client.connect(clientTransport) }
-        launch { server.connect(serverTransport) }
-
-        assertTrue(true, "Server should accept null instructions parameter")
-    }
 
     @Test
-    fun `Server constructor should work with default instructions parameter`() = runTest {
+    fun `Server constructor should work without instructions parameter`() = runTest {
         val serverInfo = Implementation(name = "test server", version = "1.0")
         val serverOptions = ServerOptions(capabilities = ServerCapabilities())
 
@@ -520,9 +504,9 @@ class ServerTest {
         val (clientTransport, serverTransport) = InMemoryTransport.createLinkedPair()
         val client = Client(clientInfo = Implementation(name = "test client", version = "1.0"))
 
-        launch { client.connect(clientTransport) }
-        launch { server.connect(serverTransport) }
+        server.connect(serverTransport)
+        client.connect(clientTransport)
 
-        assertTrue(true, "Server should work with default instructions parameter")
+        assertNull(client.serverInstructions)
     }
 }