feat(HTTP Request Tool Node): Relax binary data detection

packages/@n8n/nodes-langchain/nodes/tools/ToolHttpRequest/test/ToolHttpRequest.node.test.ts

@@ -237,6 +237,69 @@ describe('ToolHttpRequest', () => {
 				}),
 			);
 		});
+
+		it('should return the error when receiving text that contains a null character', async () => {
+			helpers.httpRequest.mockResolvedValue({
+				body: 'Hello\0World',
+				headers: {
+					'content-type': 'text/plain',
+				},
+			});
+
+			executeFunctions.getNodeParameter.mockImplementation((paramName: string) => {
+				switch (paramName) {
+					case 'method':
+						return 'GET';
+					case 'url':
+						return 'https://httpbin.org/text/plain';
+					case 'options':
+						return {};
+					case 'placeholderDefinitions.values':
+						return [];
+					default:
+						return undefined;
+				}
+			});
+
+			const { response } = await httpTool.supplyData.call(executeFunctions, 0);
+			const res = await (response as N8nTool).invoke({});
+			expect(helpers.httpRequest).toHaveBeenCalled();
+			// Check that the returned string is formatted as an error message.
+			expect(res).toContain('error');
+			expect(res).toContain('Binary data is not supported');
+		});
+
+		it('should return the error when receiving a JSON response containing a null character', async () => {
+			// Provide a raw JSON string with a literal null character.
+			helpers.httpRequest.mockResolvedValue({
+				body: '{"message":"hello\0world"}',
+				headers: {
+					'content-type': 'application/json',
+				},
+			});
+
+			executeFunctions.getNodeParameter.mockImplementation((paramName: string) => {
+				switch (paramName) {
+					case 'method':
+						return 'GET';
+					case 'url':
+						return 'https://httpbin.org/json';
+					case 'options':
+						return {};
+					case 'placeholderDefinitions.values':
+						return [];
+					default:
+						return undefined;
+				}
+			});
+
+			const { response } = await httpTool.supplyData.call(executeFunctions, 0);
+			const res = await (response as N8nTool).invoke({});
+			expect(helpers.httpRequest).toHaveBeenCalled();
+			// Check that the tool returns an error string rather than resolving to valid JSON.
+			expect(res).toContain('error');
+			expect(res).toContain('Binary data is not supported');
+		});
 	});
 
 	describe('Optimize response', () => {

packages/@n8n/nodes-langchain/nodes/tools/ToolHttpRequest/utils.ts

@@ -5,7 +5,6 @@ import { JSDOM } from 'jsdom';
 import get from 'lodash/get';
 import set from 'lodash/set';
 import unset from 'lodash/unset';
-import * as mime from 'mime-types';
 import { getOAuth2AdditionalParameters } from 'n8n-nodes-base/dist/nodes/HttpRequest/GenericFunctions';
 import type {
 	IDataObject,
@@ -146,6 +145,25 @@ const defaultOptimizer = <T>(response: T) => {
 	return String(response);
 };
 
+function isBinary(data: unknown) {
+	// Check if data is a Buffer
+	if (Buffer.isBuffer(data)) {
+		return true;
+	}
+
+	// If data is a string, assume it's text unless it contains null characters.
+	if (typeof data === 'string') {
+		// If the string contains a null character, it's likely binary.
+		if (data.includes('\0')) {
+			return true;
+		}
+		return false;
+	}
+
+	// For any other type, assume it's not binary.
+	return false;
+}
+
 const htmlOptimizer = (ctx: ISupplyDataFunctions, itemIndex: number, maxLength: number) => {
 	const cssSelector = ctx.getNodeParameter('cssSelector', itemIndex, '') as string;
 	const onlyContent = ctx.getNodeParameter('onlyContent', itemIndex, false) as boolean;
@@ -755,13 +773,8 @@ export const configureToolFunction = (
 			if (!response) {
 				try {
 					// Check if the response is binary data
-					if (fullResponse?.headers?.['content-type']) {
-						const contentType = fullResponse.headers['content-type'] as string;
-						const mimeType = contentType.split(';')[0].trim();
-
-						if (mime.charset(mimeType) !== 'UTF-8') {
-							throw new NodeOperationError(ctx.getNode(), 'Binary data is not supported');
-						}
+					if (fullResponse.body && isBinary(fullResponse.body)) {
+						throw new NodeOperationError(ctx.getNode(), 'Binary data is not supported');
 					}
 
 					response = optimizeResponse(fullResponse.body);