test: Add unit testing to nodes (no-changelog) (#4890)

* 🧪 Add base for building unit testing within nodes

* Improve helper functions

* 🧪 If node test

* 🧪 Airtable node test

* 🧪 If node test improvements

* 🧪 Airtable node test improvements

* ♻️ cleanup node unit tests

* ♻️ refactor getting node result data to use helper method

* ⚡ removed unused variables

* ♻️ Helper to read json files

---------

Co-authored-by: Marcus <marcus@n8n.io>
Co-authored-by: Michael Kret <michael.k@radency.com>

packages/nodes-base/test/nodes/Start/StartNode.test.ts

@@ -0,0 +1,48 @@
+import { INodeType } from 'n8n-workflow';
+import * as Helpers from '../Helpers';
+import { Start } from '../../../nodes/Start/Start.node';
+import { WorkflowTestData } from '../types';
+import { executeWorkflow } from '../ExecuteWorkflow';
+
+describe('Execute Start Node', () => {
+	const tests: Array<WorkflowTestData> = [
+		{
+			description: 'should run start node',
+			input: {
+				workflowData: {
+					nodes: [
+						{
+							id: 'uuid-1',
+							parameters: {},
+							name: 'Start',
+							type: 'n8n-nodes-base.start',
+							typeVersion: 1,
+							position: [100, 300],
+						},
+					],
+					connections: {},
+				},
+			},
+			output: {
+				nodeExecutionOrder: ['Start'],
+				nodeData: {},
+			},
+		},
+	];
+
+	const nodes: INodeType[] = [new Start()];
+	const nodeTypes = Helpers.setup(nodes);
+
+	for (const testData of tests) {
+		test(testData.description, async () => {
+			// execute workflow
+			const { result, nodeExecutionOrder } = await executeWorkflow(testData, nodeTypes);
+			// Check if the nodes did execute in the correct order
+			expect(nodeExecutionOrder).toEqual(testData.output.nodeExecutionOrder);
+			// Check if other data has correct value
+			expect(result.finished).toEqual(true);
+			expect(result.data.executionData!.contextData).toEqual({});
+			expect(result.data.executionData!.nodeExecutionStack).toEqual([]);
+		});
+	}
+});