Refactor streaming http tests

To provide better DSL for integration tests

kotlin-sdk-client/src/jvmTest/kotlin/io/modelcontextprotocol/kotlin/sdk/client/AbstractStreamableHttpClientTest.kt

@@ -0,0 +1,35 @@
+package io.modelcontextprotocol.kotlin.sdk.client
+
+import io.ktor.client.HttpClient
+import io.ktor.client.engine.apache5.Apache5
+import io.ktor.client.plugins.logging.LogLevel
+import io.ktor.client.plugins.logging.Logging
+import io.ktor.client.plugins.sse.SSE
+import org.junit.jupiter.api.AfterEach
+import org.junit.jupiter.api.TestInstance
+
+@TestInstance(TestInstance.Lifecycle.PER_CLASS)
+internal abstract class AbstractStreamableHttpClientTest {
+
+    // start mokksy on random port
+    protected val mockMcp: MockMcp = MockMcp(verbose = true)
+
+    @AfterEach
+    fun afterEach() {
+        mockMcp.checkForUnmatchedRequests()
+    }
+
+    protected suspend fun connect(client: Client) {
+        client.connect(
+            StreamableHttpClientTransport(
+                url = mockMcp.url,
+                client = HttpClient(Apache5) {
+                    install(SSE)
+                    install(Logging) {
+                        level = LogLevel.ALL
+                    }
+                },
+            ),
+        )
+    }
+}

kotlin-sdk-client/src/jvmTest/kotlin/io/modelcontextprotocol/kotlin/sdk/client/MockMcp.kt

@@ -1,5 +1,6 @@
 package io.modelcontextprotocol.kotlin.sdk.client
 
+import dev.mokksy.mokksy.BuildingStep
 import dev.mokksy.mokksy.Mokksy
 import dev.mokksy.mokksy.StubConfiguration
 import io.ktor.http.ContentType
@@ -7,7 +8,18 @@ import io.ktor.http.HttpMethod
 import io.ktor.http.HttpStatusCode
 import io.ktor.sse.ServerSentEvent
 import io.modelcontextprotocol.kotlin.sdk.JSONRPCRequest
+import io.modelcontextprotocol.kotlin.sdk.RequestId
 import kotlinx.coroutines.flow.Flow
+import kotlinx.serialization.json.Json
+import kotlinx.serialization.json.JsonObject
+import kotlinx.serialization.json.JsonPrimitive
+import kotlinx.serialization.json.buildJsonObject
+import kotlinx.serialization.json.contentOrNull
+import kotlinx.serialization.json.jsonObject
+import kotlinx.serialization.json.jsonPrimitive
+import kotlinx.serialization.json.putJsonObject
+
+const val MCP_SESSION_ID_HEADER = "Mcp-Session-Id"
 
 /**
  * High-level helper for simulating an MCP server over Streaming HTTP transport with Server-Sent Events (SSE),
@@ -26,51 +38,188 @@ internal class MockMcp(verbose: Boolean = false) {
         mokksy.checkForUnmatchedRequests()
     }
 
-    val url = mokksy.baseUrl() + "/mcp"
+    val url = "${mokksy.baseUrl()}/mcp"
 
     @Suppress("LongParameterList")
+    fun onInitialize(
+        clientName: String? = null,
+        sessionId: String,
+        protocolVersion: String = "2025-03-26",
+        serverName: String = "Mock MCP Server",
+        serverVersion: String = "1.0.0",
+        capabilities: JsonObject = buildJsonObject {
+            putJsonObject("tools") {
+                put("listChanged", JsonPrimitive(false))
+            }
+        },
+    ) {
+        val predicates = if (clientName != null) {
+            arrayOf<(JSONRPCRequest?) -> Boolean>({
+                it?.params?.jsonObject
+                    ?.get("clientInfo")?.jsonObject
+                    ?.get("name")?.jsonPrimitive
+                    ?.contentOrNull == clientName
+            })
+        } else {
+            emptyArray()
+        }
+
+        handleWithResult(
+            jsonRpcMethod = "initialize",
+            sessionId = sessionId,
+            bodyPredicates = predicates,
+            // language=json
+            result = """
+            {
+                "capabilities": $capabilities,
+                "protocolVersion": "$protocolVersion",
+                "serverInfo": {
+                  "name": "$serverName",
+                  "version": "$serverVersion"
+                },
+                "_meta": {
+                  "foo": "bar"
+                }
+            }
+            """.trimIndent(),
+        )
+    }
+
     fun onJSONRPCRequest(
+        httpMethod: HttpMethod = HttpMethod.Post,
+        jsonRpcMethod: String,
+        expectedSessionId: String? = null,
+        vararg bodyPredicates: (JSONRPCRequest) -> Boolean,
+    ): BuildingStep<JSONRPCRequest> = mokksy.method(
+        configuration = StubConfiguration(removeAfterMatch = true),
+        httpMethod = httpMethod,
+        requestType = JSONRPCRequest::class,
+    ) {
+        path("/mcp")
+        expectedSessionId?.let {
+            containsHeader(MCP_SESSION_ID_HEADER, it)
+        }
+        bodyMatchesPredicate(
+            description = "JSON-RPC version is '2.0'",
+            predicate =
+            {
+                it!!.jsonrpc == "2.0"
+            },
+        )
+        bodyMatchesPredicate(
+            description = "JSON-RPC Method should be '$jsonRpcMethod'",
+            predicate =
+            {
+                it!!.method == jsonRpcMethod
+            },
+        )
+        bodyPredicates.forEach { predicate ->
+            bodyMatchesPredicate(predicate = { predicate.invoke(it!!) })
+        }
+    }
+
+    @Suppress("LongParameterList")
+    fun handleWithResult(
         httpMethod: HttpMethod = HttpMethod.Post,
         jsonRpcMethod: String,
         expectedSessionId: String? = null,
         sessionId: String,
         contentType: ContentType = ContentType.Application.Json,
         statusCode: HttpStatusCode = HttpStatusCode.OK,
-        bodyBuilder: () -> String,
+        vararg bodyPredicates: (JSONRPCRequest) -> Boolean,
+        result: () -> JsonObject,
     ) {
-        mokksy.method(
-            configuration = StubConfiguration(removeAfterMatch = true),
+        onJSONRPCRequest(
             httpMethod = httpMethod,
-            requestType = JSONRPCRequest::class,
-        ) {
-            path("/mcp")
-            expectedSessionId?.let {
-                containsHeader("Mcp-Session-Id", it)
+            jsonRpcMethod = jsonRpcMethod,
+            expectedSessionId = expectedSessionId,
+            bodyPredicates = bodyPredicates,
+        ) respondsWith {
+            val requestId = when (request.body.id) {
+                is RequestId.NumberId -> (request.body.id as RequestId.NumberId).value.toString()
+                is RequestId.StringId -> "\"${(request.body.id as RequestId.StringId).value}\""
             }
-            bodyMatchesPredicates(
-                {
-                    it!!.method == jsonRpcMethod
-                },
-                {
-                    it!!.jsonrpc == "2.0"
-                },
-            )
-        } respondsWith {
-            body = bodyBuilder.invoke()
+            val resultObject = result!!.invoke()
+            // language=json
+            body = """
+             {
+              "jsonrpc": "2.0",
+              "id": $requestId,
+              "result": $resultObject
+            }
+            """.trimIndent()
             this.contentType = contentType
-            headers += "Mcp-Session-Id" to sessionId
+            headers += MCP_SESSION_ID_HEADER to sessionId
             httpStatus = statusCode
         }
     }
 
-    fun onSubscribeWithGet(sessionId: String, block: () -> Flow<ServerSentEvent>) {
-        mokksy.get(name = "MCP GETs", requestType = Any::class) {
-            path("/mcp")
-            containsHeader("Mcp-Session-Id", sessionId)
-            containsHeader("Accept", "application/json,text/event-stream")
-            containsHeader("Cache-Control", "no-store")
-        } respondsWithSseStream {
-            headers += "Mcp-Session-Id" to sessionId
+    @Suppress("LongParameterList")
+    fun handleWithResult(
+        httpMethod: HttpMethod = HttpMethod.Post,
+        jsonRpcMethod: String,
+        expectedSessionId: String? = null,
+        sessionId: String,
+        contentType: ContentType = ContentType.Application.Json,
+        statusCode: HttpStatusCode = HttpStatusCode.OK,
+        vararg bodyPredicates: (JSONRPCRequest) -> Boolean,
+        result: String,
+    ) {
+        handleWithResult(
+            httpMethod = httpMethod,
+            jsonRpcMethod = jsonRpcMethod,
+            expectedSessionId = expectedSessionId,
+            sessionId = sessionId,
+            contentType = contentType,
+            statusCode = statusCode,
+            bodyPredicates = bodyPredicates,
+            result = {
+                Json.parseToJsonElement(result).jsonObject
+            },
+        )
+    }
+
+    @Suppress("LongParameterList")
+    fun handleJSONRPCRequest(
+        httpMethod: HttpMethod = HttpMethod.Post,
+        jsonRpcMethod: String,
+        expectedSessionId: String? = null,
+        sessionId: String,
+        contentType: ContentType = ContentType.Application.Json,
+        statusCode: HttpStatusCode = HttpStatusCode.OK,
+        vararg bodyPredicates: (JSONRPCRequest?) -> Boolean,
+        bodyBuilder: () -> String = { "" },
+    ) {
+        onJSONRPCRequest(
+            httpMethod = httpMethod,
+            jsonRpcMethod = jsonRpcMethod,
+            expectedSessionId = expectedSessionId,
+            bodyPredicates = bodyPredicates,
+        ) respondsWith {
+            body = bodyBuilder.invoke()
+            this.contentType = contentType
+            headers += MCP_SESSION_ID_HEADER to sessionId
+            httpStatus = statusCode
+        }
+    }
+
+    fun onSubscribe(httpMethod: HttpMethod = HttpMethod.Post, sessionId: String): BuildingStep<Any> = mokksy.method(
+        httpMethod = httpMethod,
+        name = "MCP GETs",
+        requestType = Any::class,
+    ) {
+        path("/mcp")
+        containsHeader(MCP_SESSION_ID_HEADER, sessionId)
+        containsHeader("Accept", "application/json,text/event-stream")
+        containsHeader("Cache-Control", "no-store")
+    }
+
+    fun handleSubscribeWithGet(sessionId: String, block: () -> Flow<ServerSentEvent>) {
+        onSubscribe(
+            httpMethod = HttpMethod.Get,
+            sessionId = sessionId,
+        ) respondsWithSseStream {
+            headers += MCP_SESSION_ID_HEADER to sessionId
             this.flow = block.invoke()
         }
     }
@@ -81,7 +230,7 @@ internal class MockMcp(verbose: Boolean = false) {
             requestType = JSONRPCRequest::class,
         ) {
             path("/mcp")
-            containsHeader("Mcp-Session-Id", sessionId)
+            containsHeader(MCP_SESSION_ID_HEADER, sessionId)
         } respondsWith {
             body = null
         }

kotlin-sdk-client/src/jvmTest/kotlin/io/modelcontextprotocol/kotlin/sdk/client/StreamableHttpClientTest.kt

@@ -1,11 +1,6 @@
 package io.modelcontextprotocol.kotlin.sdk.client
 
 import io.kotest.matchers.collections.shouldContain
-import io.ktor.client.HttpClient
-import io.ktor.client.engine.apache5.Apache5
-import io.ktor.client.plugins.logging.LogLevel
-import io.ktor.client.plugins.logging.Logging
-import io.ktor.client.plugins.sse.SSE
 import io.ktor.http.HttpStatusCode
 import io.ktor.sse.ServerSentEvent
 import io.modelcontextprotocol.kotlin.sdk.ClientCapabilities
@@ -19,7 +14,6 @@ import kotlinx.serialization.json.put
 import kotlinx.serialization.json.putJsonObject
 import org.junit.jupiter.api.TestInstance
 import java.util.UUID
-import kotlin.test.AfterTest
 import kotlin.test.Test
 import kotlin.time.Duration.Companion.milliseconds
 
@@ -30,21 +24,16 @@ import kotlin.time.Duration.Companion.milliseconds
  * @author Konstantin Pavlov
  */
 @TestInstance(TestInstance.Lifecycle.PER_CLASS)
-class StreamableHttpClientTest {
-
-    // start mokksy on random port
-    private val mockMcp: MockMcp = MockMcp(verbose = true)
-
-    @AfterTest
-    fun afterEach() {
-        mockMcp.checkForUnmatchedRequests()
-    }
+@Suppress("LongMethod")
+internal class StreamableHttpClientTest : AbstractStreamableHttpClientTest() {
 
     @Test
-    @Suppress("LongMethod")
-    fun `test streamableHttpClient`(): Unit = runBlocking {
+    fun `test streamableHttpClient`() = runBlocking {
         val client = Client(
-            clientInfo = Implementation(name = "sample-client", version = "1.0.0"),
+            clientInfo = Implementation(
+                name = "client1",
+                version = "1.0.0",
+            ),
             options = ClientOptions(
                 capabilities = ClientCapabilities(),
             ),
@@ -52,44 +41,19 @@ class StreamableHttpClientTest {
 
         val sessionId = UUID.randomUUID().toString()
 
-        mockMcp.onJSONRPCRequest(
-            jsonRpcMethod = "initialize",
+        mockMcp.onInitialize(
+            clientName = "client1",
             sessionId = sessionId,
-        ) {
-            // language=json
-            """
-            {
-              "jsonrpc": "2.0",
-              "id": 1,
-              "result": {
-                "capabilities": {
-                  "tools": {
-                     "listChanged": false
-                  }
-                },
-                "protocolVersion": "2025-03-26",
-                "serverInfo": {
-                  "name": "Mock MCP Server",
-                  "version": "1.0.0"
-                },
-                "_meta": {
-                  "foo": "bar"
-                }
-              }
-            }
-            """.trimIndent()
-        }
+        )
 
-        mockMcp.onJSONRPCRequest(
+        mockMcp.handleJSONRPCRequest(
             jsonRpcMethod = "notifications/initialized",
             expectedSessionId = sessionId,
             sessionId = sessionId,
             statusCode = HttpStatusCode.Accepted,
-        ) {
-            ""
-        }
+        )
 
-        mockMcp.onSubscribeWithGet(sessionId) {
+        mockMcp.handleSubscribeWithGet(sessionId) {
             flow {
                 delay(500.milliseconds)
                 emit(
@@ -112,30 +76,14 @@ class StreamableHttpClientTest {
             }
         }
 
-        client.connect(
-            StreamableHttpClientTransport(
-                url = mockMcp.url,
-                client = HttpClient(Apache5) {
-                    install(SSE)
-                    install(Logging) {
-                        level = LogLevel.ALL
-                    }
-                },
-            ),
-        )
-
         // TODO: how to get notifications via Client API?
 
-        mockMcp.onJSONRPCRequest(
+        mockMcp.handleWithResult(
             jsonRpcMethod = "tools/list",
             sessionId = sessionId,
-        ) {
             // language=json
-            """
-             {
-              "jsonrpc": "2.0",
-              "id": 3,
-              "result": {
+            result = """
+              {
                 "tools": [
                   {
                     "name": "get_weather",
@@ -164,9 +112,10 @@ class StreamableHttpClientTest {
                   }
                 ]
               }
-            }
-            """.trimIndent()
-        }
+            """.trimIndent(),
+        )
+
+        connect(client)
 
         val listToolsResult = client.listTools()
 

kotlin-sdk-client/src/jvmTest/resources/simplelogger.properties

@@ -1,14 +1,9 @@
 # Level of logging for the ROOT logger: ERROR, WARN, INFO, DEBUG, TRACE (default is INFO)
 org.slf4j.simpleLogger.defaultLogLevel=INFO
-
-
 org.slf4j.simpleLogger.showThreadName=true
 org.slf4j.simpleLogger.showDateTime=false
 
-# Whether to enable stack traces for exceptions (true/false, default is true)
-org.slf4j.simpleLogger.showShortLogName=false
-
 # Log level for specific packages or classes
 org.slf4j.simpleLogger.log.io.ktor.server=DEBUG
-org.slf4j.simpleLogger.log.io.modelcontextprotocol=TRACE
+org.slf4j.simpleLogger.log.io.modelcontextprotocol=DEBUG
 org.slf4j.simpleLogger.log.dev.mokksy=DEBUG