Resolve HTTP transport merge conflict

Author: NewPeople-star

mcp-test/src/test/java/io/modelcontextprotocol/client/transport/HttpClientStreamableHttpTransportInvalidJsonResponseTest.java

@@ -0,0 +1,86 @@
+/*
+ * Copyright 2024-2026 the original author or authors.
+ */
+
+package io.modelcontextprotocol.client.transport;
+
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.time.Duration;
+
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.Timeout;
+
+import com.sun.net.httpserver.HttpServer;
+
+import io.modelcontextprotocol.spec.McpSchema;
+import io.modelcontextprotocol.spec.McpTransportException;
+import io.modelcontextprotocol.spec.ProtocolVersions;
+import io.modelcontextprotocol.server.transport.TomcatTestUtil;
+import reactor.test.StepVerifier;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Verifies that an {@code application/json} response whose body is not valid JSON fails
+ * the {@link HttpClientStreamableHttpTransport#sendMessage} mono with the parsing error
+ * instead of completing it successfully.
+ *
+ * <p>
+ * Completing the delivery sink before deserialization used to swallow the parse failure:
+ * the {@code McpClientSession} then never received the error, kept the pending response
+ * entry and the caller only saw a {@code TimeoutException} once the request timeout
+ * elapsed.
+ *
+ * @see <a href="https://github.com/modelcontextprotocol/java-sdk/issues/1147">#1147</a>
+ */
+public class HttpClientStreamableHttpTransportInvalidJsonResponseTest {
+
+	static int PORT = TomcatTestUtil.findAvailablePort();
+
+	static String host = "http://localhost:" + PORT;
+
+	static HttpServer server;
+
+	@BeforeAll
+	static void startServer() throws IOException {
+		server = HttpServer.create(new InetSocketAddress(PORT), 0);
+
+		// 200 OK with an invalid JSON body for the /mcp endpoint
+		server.createContext("/mcp", exchange -> {
+			byte[] body = "{broken".getBytes();
+			exchange.getResponseHeaders().set("Content-Type", "application/json");
+			exchange.sendResponseHeaders(200, body.length);
+			exchange.getResponseBody().write(body);
+			exchange.close();
+		});
+
+		server.setExecutor(null);
+		server.start();
+	}
+
+	@AfterAll
+	static void stopServer() {
+		server.stop(1);
+	}
+
+	@Test
+	@Timeout(10)
+	void testInvalidJsonResponseFailsWithParseError() {
+		var transport = HttpClientStreamableHttpTransport.builder(host).build();
+
+		var initializeRequest = McpSchema.InitializeRequest
+			.builder(ProtocolVersions.MCP_2025_03_26, McpSchema.ClientCapabilities.builder().roots(true).build(),
+					McpSchema.Implementation.builder("MCP Client", "0.3.1").build())
+			.build();
+		var testMessage = new McpSchema.JSONRPCRequest(McpSchema.METHOD_INITIALIZE, "test-id", initializeRequest);
+
+		StepVerifier.create(transport.sendMessage(testMessage)).expectErrorSatisfies(error -> {
+			// The parse failure must surface as the delivery error, not a timeout
+			assertThat(error).isInstanceOf(McpTransportException.class);
+		}).verify(Duration.ofSeconds(5));
+	}
+
+}