fix(core): Wrap nodes for tool use at a suitable time (#11238)

Co-authored-by: कारतोफ्फेलस्क्रिप्ट™ <aditya@netroy.in>

packages/cli/src/__tests__/node-types.test.ts

@@ -0,0 +1,100 @@
+import { mock } from 'jest-mock-extended';
+import type { INodeType, IVersionedNodeType } from 'n8n-workflow';
+
+import type { LoadNodesAndCredentials } from '@/load-nodes-and-credentials';
+
+import { NodeTypes } from '../node-types';
+
+describe('NodeTypes', () => {
+	let nodeTypes: NodeTypes;
+	const loadNodesAndCredentials = mock<LoadNodesAndCredentials>();
+
+	beforeEach(() => {
+		jest.clearAllMocks();
+		nodeTypes = new NodeTypes(loadNodesAndCredentials);
+	});
+
+	describe('getByNameAndVersion', () => {
+		const nodeTypeName = 'n8n-nodes-base.testNode';
+
+		it('should throw an error if the node-type does not exist', () => {
+			const nodeTypeName = 'unknownNode';
+
+			// @ts-expect-error overwriting a readonly property
+			loadNodesAndCredentials.loadedNodes = {};
+			// @ts-expect-error overwriting a readonly property
+			loadNodesAndCredentials.knownNodes = {};
+
+			expect(() => nodeTypes.getByNameAndVersion(nodeTypeName)).toThrow(
+				'Unrecognized node type: unknownNode',
+			);
+		});
+
+		it('should return a regular node-type without version', () => {
+			const nodeType = mock<INodeType>();
+
+			// @ts-expect-error overwriting a readonly property
+			loadNodesAndCredentials.loadedNodes = {
+				[nodeTypeName]: { type: nodeType },
+			};
+
+			const result = nodeTypes.getByNameAndVersion(nodeTypeName);
+
+			expect(result).toEqual(nodeType);
+		});
+
+		it('should return a regular node-type with version', () => {
+			const nodeTypeV1 = mock<INodeType>();
+			const nodeType = mock<IVersionedNodeType>({
+				nodeVersions: { 1: nodeTypeV1 },
+				getNodeType: () => nodeTypeV1,
+			});
+
+			// @ts-expect-error overwriting a readonly property
+			loadNodesAndCredentials.loadedNodes = {
+				[nodeTypeName]: { type: nodeType },
+			};
+
+			const result = nodeTypes.getByNameAndVersion(nodeTypeName);
+
+			expect(result).toEqual(nodeTypeV1);
+		});
+
+		it('should throw when a node-type is requested as tool, but does not support being used as one', () => {
+			const nodeType = mock<INodeType>();
+
+			// @ts-expect-error overwriting a readonly property
+			loadNodesAndCredentials.loadedNodes = {
+				[nodeTypeName]: { type: nodeType },
+			};
+
+			expect(() => nodeTypes.getByNameAndVersion(`${nodeTypeName}Tool`)).toThrow(
+				'Node cannot be used as a tool',
+			);
+		});
+
+		it('should return the tool node-type when requested as tool', () => {
+			const nodeType = mock<INodeType>();
+			// @ts-expect-error can't use a mock here
+			nodeType.description = {
+				name: nodeTypeName,
+				displayName: 'TestNode',
+				usableAsTool: true,
+				properties: [],
+			};
+
+			// @ts-expect-error overwriting a readonly property
+			loadNodesAndCredentials.loadedNodes = {
+				[nodeTypeName]: { type: nodeType },
+			};
+
+			const result = nodeTypes.getByNameAndVersion(`${nodeTypeName}Tool`);
+			expect(result).not.toEqual(nodeType);
+			expect(result.description.name).toEqual('n8n-nodes-base.testNodeTool');
+			expect(result.description.displayName).toEqual('TestNode Tool');
+			expect(result.description.codex?.categories).toContain('AI');
+			expect(result.description.inputs).toEqual([]);
+			expect(result.description.outputs).toEqual(['ai_tool']);
+		});
+	});
+});

packages/cli/src/node-types.ts

@@ -44,15 +44,38 @@ export class NodeTypes implements INodeTypes {
 	}
 
 	getByNameAndVersion(nodeType: string, version?: number): INodeType {
-		const versionedNodeType = NodeHelpers.getVersionedNodeType(
-			this.getNode(nodeType).type,
-			version,
-		);
-		if (versionedNodeType.description.usableAsTool) {
-			return NodeHelpers.convertNodeToAiTool(versionedNodeType);
+		const origType = nodeType;
+		const toolRequested = nodeType.startsWith('n8n-nodes-base') && nodeType.endsWith('Tool');
+		// Make sure the nodeType to actually get from disk is the un-wrapped type
+		if (toolRequested) {
+			nodeType = nodeType.replace(/Tool$/, '');
+		}
+
+		const node = this.getNode(nodeType);
+		const versionedNodeType = NodeHelpers.getVersionedNodeType(node.type, version);
+		if (!toolRequested) return versionedNodeType;
+
+		if (!versionedNodeType.description.usableAsTool)
+			throw new ApplicationError('Node cannot be used as a tool', { extra: { nodeType } });
+
+		const { loadedNodes } = this.loadNodesAndCredentials;
+		if (origType in loadedNodes) {
+			return loadedNodes[origType].type as INodeType;
 		}
 
-		return versionedNodeType;
+		// Instead of modifying the existing type, we extend it into a new type object
+		const clonedProperties = Object.create(
+			versionedNodeType.description.properties,
+		) as INodeTypeDescription['properties'];
+		const clonedDescription = Object.create(versionedNodeType.description, {
+			properties: { value: clonedProperties },
+		}) as INodeTypeDescription;
+		const clonedNode = Object.create(versionedNodeType, {
+			description: { value: clonedDescription },
+		}) as INodeType;
+		const tool = NodeHelpers.convertNodeToAiTool(clonedNode);
+		loadedNodes[nodeType + 'Tool'] = { sourcePath: '', type: tool };
+		return tool;
 	}
 
 	/* Some nodeTypes need to get special parameters applied like the polling nodes the polling times */