fix(RSS Feed Trigger Node): Handle empty items gracefully (#10855)

packages/nodes-base/nodes/RssFeedRead/RssFeedReadTrigger.node.ts

@@ -9,6 +9,11 @@ import { NodeConnectionType, NodeOperationError } from 'n8n-workflow';
 import Parser from 'rss-parser';
 import moment from 'moment-timezone';
 
+interface PollData {
+	lastItemDate?: string;
+	lastTimeChecked?: string;
+}
+
 export class RssFeedReadTrigger implements INodeType {
 	description: INodeTypeDescription = {
 		displayName: 'RSS Feed Trigger',
@@ -39,12 +44,12 @@ export class RssFeedReadTrigger implements INodeType {
 	};
 
 	async poll(this: IPollFunctions): Promise<INodeExecutionData[][] | null> {
-		const pollData = this.getWorkflowStaticData('node');
+		const pollData = this.getWorkflowStaticData('node') as PollData;
 		const feedUrl = this.getNodeParameter('feedUrl') as string;
 
-		const now = moment().utc().format();
+		const dateToCheck = Date.parse(
-		const dateToCheck =
+			pollData.lastItemDate ?? pollData.lastTimeChecked ?? moment().utc().format(),
-			(pollData.lastItemDate as string) || (pollData.lastTimeChecked as string) || now;
+		);
 
 		if (!feedUrl) {
 			throw new NodeOperationError(this.getNode(), 'The parameter "URL" has to be set!');
@@ -73,14 +78,15 @@ export class RssFeedReadTrigger implements INodeType {
 				return [this.helpers.returnJsonArray(feed.items[0])];
 			}
 			feed.items.forEach((item) => {
-				if (Date.parse(item.isoDate as string) > Date.parse(dateToCheck)) {
+				if (Date.parse(item.isoDate as string) > dateToCheck) {
 					returnData.push(item);
 				}
 			});
-			const maxIsoDate = feed.items.reduce((a, b) =>
+
-				new Date(a.isoDate as string) > new Date(b.isoDate as string) ? a : b,
+			if (feed.items.length) {
-			).isoDate;
+				const maxIsoDate = Math.max(...feed.items.map(({ isoDate }) => Date.parse(isoDate!)));
-			pollData.lastItemDate = maxIsoDate;
+				pollData.lastItemDate = new Date(maxIsoDate).toISOString();
+			}
 		}
 
 		if (Array.isArray(returnData) && returnData.length !== 0) {

packages/nodes-base/nodes/RssFeedRead/test/RssFeedRead.test.ts

@@ -0,0 +1,64 @@
+import { mock } from 'jest-mock-extended';
+import type { IPollFunctions } from 'n8n-workflow';
+import Parser from 'rss-parser';
+import { returnJsonArray } from 'n8n-core';
+import { RssFeedReadTrigger } from '../RssFeedReadTrigger.node';
+
+jest.mock('rss-parser');
+
+const now = new Date('2024-02-01T01:23:45.678Z');
+jest.useFakeTimers({ now });
+
+describe('RssFeedReadTrigger', () => {
+	describe('poll', () => {
+		const feedUrl = 'https://example.com/feed';
+		const lastItemDate = '2022-01-01T00:00:00.000Z';
+		const newItemDate = '2022-01-02T00:00:00.000Z';
+
+		const node = new RssFeedReadTrigger();
+		const pollFunctions = mock<IPollFunctions>({
+			helpers: mock({ returnJsonArray }),
+		});
+
+		it('should throw an error if the feed URL is empty', async () => {
+			pollFunctions.getNodeParameter.mockReturnValue('');
+
+			await expect(node.poll.call(pollFunctions)).rejects.toThrowError();
+
+			expect(pollFunctions.getNodeParameter).toHaveBeenCalledWith('feedUrl');
+			expect(Parser.prototype.parseURL).not.toHaveBeenCalled();
+		});
+
+		it('should return new items from the feed', async () => {
+			const pollData = mock({ lastItemDate });
+			pollFunctions.getNodeParameter.mockReturnValue(feedUrl);
+			pollFunctions.getWorkflowStaticData.mockReturnValue(pollData);
+			(Parser.prototype.parseURL as jest.Mock).mockResolvedValue({
+				items: [{ isoDate: lastItemDate }, { isoDate: newItemDate }],
+			});
+
+			const result = await node.poll.call(pollFunctions);
+
+			expect(result).toEqual([[{ json: { isoDate: newItemDate } }]]);
+			expect(pollFunctions.getWorkflowStaticData).toHaveBeenCalledWith('node');
+			expect(pollFunctions.getNodeParameter).toHaveBeenCalledWith('feedUrl');
+			expect(Parser.prototype.parseURL).toHaveBeenCalledWith(feedUrl);
+			expect(pollData.lastItemDate).toEqual(newItemDate);
+		});
+
+		it('should return null if the feed is empty', async () => {
+			const pollData = mock({ lastItemDate });
+			pollFunctions.getNodeParameter.mockReturnValue(feedUrl);
+			pollFunctions.getWorkflowStaticData.mockReturnValue(pollData);
+			(Parser.prototype.parseURL as jest.Mock).mockResolvedValue({ items: [] });
+
+			const result = await node.poll.call(pollFunctions);
+
+			expect(result).toEqual(null);
+			expect(pollFunctions.getWorkflowStaticData).toHaveBeenCalledWith('node');
+			expect(pollFunctions.getNodeParameter).toHaveBeenCalledWith('feedUrl');
+			expect(Parser.prototype.parseURL).toHaveBeenCalledWith(feedUrl);
+			expect(pollData.lastItemDate).toEqual(lastItemDate);
+		});
+	});
+});

packages/nodes-base/nodes/RssFeedRead/test/node/RssFeedRead.test.ts

@@ -4,7 +4,7 @@ import { setup, equalityTest, workflowToTests, getWorkflowFilenames } from '@tes
 // eslint-disable-next-line n8n-local-rules/no-unneeded-backticks
 const feed = `<?xml version="1.0" encoding="UTF-8"?><rss xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:content="http://purl.org/rss/1.0/modules/content/" xmlns:atom="http://www.w3.org/2005/Atom" version="2.0"><channel><title><![CDATA[Lorem ipsum feed for an interval of 1 minutes with 3 item(s)]]></title><description><![CDATA[This is a constantly updating lorem ipsum feed]]></description><link>http://example.com/</link><generator>RSS for Node</generator><lastBuildDate>Thu, 09 Feb 2023 13:40:32 GMT</lastBuildDate><pubDate>Thu, 09 Feb 2023 13:40:00 GMT</pubDate><copyright><![CDATA[Michael Bertolacci, licensed under a Creative Commons Attribution 3.0 Unported License.]]></copyright><ttl>1</ttl><item><title><![CDATA[Lorem ipsum 2023-02-09T13:40:00Z]]></title><description><![CDATA[Fugiat excepteur exercitation tempor ut aute sunt pariatur veniam pariatur dolor.]]></description><link>http://example.com/test/1675950000</link><guid isPermaLink="true">http://example.com/test/1675950000</guid><dc:creator><![CDATA[John Smith]]></dc:creator><pubDate>Thu, 09 Feb 2023 13:40:00 GMT</pubDate></item><item><title><![CDATA[Lorem ipsum 2023-02-09T13:39:00Z]]></title><description><![CDATA[Laboris quis nulla tempor eu ullamco est esse qui aute commodo aliqua occaecat.]]></description><link>http://example.com/test/1675949940</link><guid isPermaLink="true">http://example.com/test/1675949940</guid><dc:creator><![CDATA[John Smith]]></dc:creator><pubDate>Thu, 09 Feb 2023 13:39:00 GMT</pubDate></item><item><title><![CDATA[Lorem ipsum 2023-02-09T13:38:00Z]]></title><description><![CDATA[Irure labore dolor dolore sint aliquip eu anim aute anim et nulla adipisicing nostrud.]]></description><link>http://example.com/test/1675949880</link><guid isPermaLink="true">http://example.com/test/1675949880</guid><dc:creator><![CDATA[John Smith]]></dc:creator><pubDate>Thu, 09 Feb 2023 13:38:00 GMT</pubDate></item></channel></rss>`;
 
-describe('Test HTTP Request Node', () => {
+describe('Test RSS Feed Trigger Node', () => {
 	const workflows = getWorkflowFilenames(__dirname);
 	const tests = workflowToTests(workflows);