feat(core): Improve nodeNameToToolName special characters normalization (#15126)

packages/@n8n/nodes-langchain/utils/helpers.ts

@@ -251,6 +251,10 @@ export function unwrapNestedOutput(output: Record<string, unknown>): Record<stri
 	return output;
 }
 
+/**
+ * Converts a node name to a valid tool name by replacing special characters with underscores
+ * and collapsing consecutive underscores into a single one.
+ */
 export function nodeNameToToolName(node: INode): string {
-	return node.name.replace(/ /g, '_');
+	return node.name.replace(/[\s.?!=+#@&*()[\]{}:;,<>\/\\'"^%$]/g, '_').replace(/_+/g, '_');
 }

packages/@n8n/nodes-langchain/utils/tests/helpers.test.ts

@@ -5,9 +5,62 @@ import { NodeOperationError } from 'n8n-workflow';
 import type { ISupplyDataFunctions, IExecuteFunctions, INode } from 'n8n-workflow';
 import { z } from 'zod';
 
-import { escapeSingleCurlyBrackets, getConnectedTools, unwrapNestedOutput } from '../helpers';
+import {
+	escapeSingleCurlyBrackets,
+	getConnectedTools,
+	nodeNameToToolName,
+	unwrapNestedOutput,
+} from '../helpers';
 import { N8nTool } from '../N8nTool';
 
+describe('nodeNameToToolName', () => {
+	const getNodeWithName = (name: string): INode => ({
+		id: 'test-node',
+		name,
+		type: 'test',
+		typeVersion: 1,
+		position: [0, 0] as [number, number],
+		parameters: {},
+	});
+	it('should replace spaces with underscores', () => {
+		expect(nodeNameToToolName(getNodeWithName('Test Node'))).toBe('Test_Node');
+	});
+
+	it('should replace dots with underscores', () => {
+		expect(nodeNameToToolName(getNodeWithName('Test.Node'))).toBe('Test_Node');
+	});
+
+	it('should replace question marks with underscores', () => {
+		expect(nodeNameToToolName(getNodeWithName('Test?Node'))).toBe('Test_Node');
+	});
+
+	it('should replace exclamation marks with underscores', () => {
+		expect(nodeNameToToolName(getNodeWithName('Test!Node'))).toBe('Test_Node');
+	});
+
+	it('should replace equals signs with underscores', () => {
+		expect(nodeNameToToolName(getNodeWithName('Test=Node'))).toBe('Test_Node');
+	});
+
+	it('should replace multiple special characters with underscores', () => {
+		expect(nodeNameToToolName(getNodeWithName('Test.Node?With!Special=Chars'))).toBe(
+			'Test_Node_With_Special_Chars',
+		);
+	});
+
+	it('should handle names that already have underscores', () => {
+		expect(nodeNameToToolName(getNodeWithName('Test_Node'))).toBe('Test_Node');
+	});
+
+	it('should handle names with consecutive special characters', () => {
+		expect(nodeNameToToolName(getNodeWithName('Test..!!??==Node'))).toBe('Test_Node');
+	});
+
+	it('should replace various special characters with underscores', () => {
+		expect(nodeNameToToolName(getNodeWithName('Test#+*()[]{}:;,<>/\\\'"%$Node'))).toBe('Test_Node');
+	});
+});
+
 describe('escapeSingleCurlyBrackets', () => {
 	it('should return undefined when input is undefined', () => {
 		expect(escapeSingleCurlyBrackets(undefined)).toBeUndefined();
@@ -166,7 +219,7 @@ describe('getConnectedTools', () => {
 			name: 'Test Node',
 			type: 'test',
 			typeVersion: 1,
-			position: [0, 0],
+			position: [0, 0] as [number, number],
 			parameters: {},
 		};