Add tests for McpWebFluxServerAutoConfiguration

Add unit tests to verify that the WebFlux server transport is properly configured
with a custom ObjectMapper that ignores unknown properties. This ensures that the
MCP server can handle JSON payloads containing fields not defined in the model
classes, which is important for forward compatibility.

Signed-off-by: Hari Ohm Prasath <[email protected]>
Signed-off-by: Hari Ohm Prasth Rajagopal <[email protected]>

Author: bullet-dev-team

auto-configurations/mcp/spring-ai-autoconfigure-mcp-server/src/test/java/org/springframework/ai/mcp/server/autoconfigure/McpWebFluxServerAutoConfigurationTests.java

@@ -0,0 +1,87 @@
+/*
+ * Copyright 2025-2025 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.ai.mcp.server.autoconfigure;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.reactive.function.server.RouterFunction;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import io.modelcontextprotocol.server.transport.WebFluxSseServerTransportProvider;
+
+class McpWebFluxServerAutoConfigurationTests {
+
+	private final ApplicationContextRunner contextRunner = new ApplicationContextRunner()
+		.withConfiguration(AutoConfigurations.of(McpWebFluxServerAutoConfiguration.class,
+				JacksonAutoConfiguration.class, TestConfiguration.class));
+
+	@Test
+	void shouldConfigureWebFluxTransportWithCustomObjectMapper() {
+		this.contextRunner.run((context) -> {
+			assertThat(context).hasSingleBean(WebFluxSseServerTransportProvider.class);
+			assertThat(context).hasSingleBean(RouterFunction.class);
+			assertThat(context).hasSingleBean(McpServerProperties.class);
+
+			ObjectMapper objectMapper = context.getBean(ObjectMapper.class);
+
+			// Verify that the ObjectMapper is configured to ignore unknown properties
+			assertThat(objectMapper.getDeserializationConfig()
+				.isEnabled(com.fasterxml.jackson.databind.DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)).isFalse();
+
+			// Test with a JSON payload containing unknown fields
+			String jsonWithUnknownField = """
+					{
+					    "tools": ["tool1", "tool2"],
+					    "name": "test",
+					    "unknownField": "value"
+					}
+					""";
+
+			// This should not throw an exception
+			TestMessage message = objectMapper.readValue(jsonWithUnknownField, TestMessage.class);
+			assertThat(message.getName()).isEqualTo("test");
+		});
+	}
+
+	// Test configuration to enable McpServerProperties
+	@Configuration
+	@EnableConfigurationProperties(McpServerProperties.class)
+	static class TestConfiguration {
+
+	}
+
+	// Test class to simulate the actual message structure
+	static class TestMessage {
+
+		private String name;
+
+		public String getName() {
+			return name;
+		}
+
+		public void setName(String name) {
+			this.name = name;
+		}
+
+	}
+
+}