Notify resources list_changed when removing a resource template (#1266)

McpAsyncServer#removeResourceTemplate removed the template but never sent
notifications/resources/list_changed, unlike addResourceTemplate and
removeResource. Send it when a template was removed and the server declares
resources.listChanged.

Author: subhashpolisetti

mcp-core/src/main/java/io/modelcontextprotocol/server/McpAsyncServer.java

@@ -723,6 +723,10 @@ public Mono<Void> removeResourceTemplate(String uriTemplate) {
 			McpServerFeatures.AsyncResourceTemplateSpecification removed = this.resourceTemplates.remove(uriTemplate);
 			if (removed != null) {
 				logger.debug("Removed resource template: {}", uriTemplate);
+				if (Boolean.TRUE.equals(this.serverCapabilities.resources().listChanged())) {
+					return notifyResourcesListChanged();
+				}
+				return Mono.empty();
 			}
 			else {
 				logger.warn("Failed to remove a resource template with URI '{}' (not found)", uriTemplate);

mcp-test/src/test/java/io/modelcontextprotocol/server/DerivedCapabilitiesRuntimeChangesTests.java

@@ -78,6 +78,7 @@ void addAndRemoveResourceAndTemplateWithDerivedCapabilities() {
 		StepVerifier.create(server.addResource(asyncResource("test://added"))).verifyComplete();
 		StepVerifier.create(server.removeResource("test://initial")).verifyComplete();
 		StepVerifier.create(server.addResourceTemplate(asyncTemplate("test://items/{id}"))).verifyComplete();
+		StepVerifier.create(server.removeResourceTemplate("test://items/{id}")).verifyComplete();
 
 		assertThat(transport.getAllSentMessages()).isEmpty();
 	}

mcp-test/src/test/java/io/modelcontextprotocol/server/ResourceTemplateManagementTests.java

@@ -9,6 +9,8 @@
 
 import io.modelcontextprotocol.MockMcpServerTransport;
 import io.modelcontextprotocol.MockMcpServerTransportProvider;
+import io.modelcontextprotocol.spec.McpSchema;
+import io.modelcontextprotocol.spec.McpSchema.JSONRPCNotification;
 import io.modelcontextprotocol.spec.McpSchema.ReadResourceResult;
 import io.modelcontextprotocol.spec.McpSchema.ResourceTemplate;
 import io.modelcontextprotocol.spec.McpSchema.ServerCapabilities;
@@ -146,6 +148,38 @@ void testRemoveNonexistentResourceTemplate() {
 		StepVerifier.create(mcpAsyncServer.removeResourceTemplate("nonexistent://template/{id}")).verifyComplete();
 	}
 
+	@Test
+	void testRemoveResourceTemplateNotifiesListChanged() {
+		ResourceTemplate template = ResourceTemplate.builder(TEST_TEMPLATE_URI, TEST_TEMPLATE_NAME).build();
+
+		McpServerFeatures.AsyncResourceTemplateSpecification specification = new McpServerFeatures.AsyncResourceTemplateSpecification(
+				template, (exchange, req) -> Mono.just(ReadResourceResult.builder(List.of()).build()));
+
+		mcpAsyncServer = McpServer.async(mockTransportProvider)
+			.serverInfo("test-server", "1.0.0")
+			.capabilities(ServerCapabilities.builder().resources(false, true).build())
+			.resourceTemplates(specification)
+			.build();
+
+		StepVerifier.create(mcpAsyncServer.removeResourceTemplate(TEST_TEMPLATE_URI)).verifyComplete();
+
+		assertThat(mockTransportProvider.getTransport().getAllSentMessages()).singleElement()
+			.isInstanceOfSatisfying(JSONRPCNotification.class, notification -> assertThat(notification.method())
+				.isEqualTo(McpSchema.METHOD_NOTIFICATION_RESOURCES_LIST_CHANGED));
+	}
+
+	@Test
+	void testRemoveNonexistentResourceTemplateDoesNotNotify() {
+		mcpAsyncServer = McpServer.async(mockTransportProvider)
+			.serverInfo("test-server", "1.0.0")
+			.capabilities(ServerCapabilities.builder().resources(false, true).build())
+			.build();
+
+		StepVerifier.create(mcpAsyncServer.removeResourceTemplate("nonexistent://template/{id}")).verifyComplete();
+
+		assertThat(mockTransportProvider.getTransport().getAllSentMessages()).isEmpty();
+	}
+
 	@Test
 	void testReplaceExistingResourceTemplate() {
 		ResourceTemplate originalTemplate = ResourceTemplate.builder(TEST_TEMPLATE_URI, TEST_TEMPLATE_NAME)