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/If/If.node.test.ts

@@ -0,0 +1,58 @@
+import { INodeType } from 'n8n-workflow';
+import * as Helpers from '../Helpers';
+import { WorkflowTestData } from '../types';
+
+import { ManualTrigger } from '../../../nodes/ManualTrigger/ManualTrigger.node';
+import { Set } from '../../../nodes/Set/Set.node';
+import { If } from '../../../nodes/If/If.node';
+import { NoOp } from '../../../nodes/NoOp/NoOp.node';
+import { Code } from '../../../nodes/Code/Code.node';
+
+import { executeWorkflow } from '../ExecuteWorkflow';
+
+describe('Execute If Node', () => {
+	const tests: Array<WorkflowTestData> = [
+		{
+			description: 'should execute IF node true/false boolean',
+			input: {
+				workflowData: Helpers.readJsonFileSync('test/nodes/If/workflow.json'),
+			},
+			output: {
+				nodeData: {
+					'On True': [
+						[
+							{
+								value: true,
+							},
+						],
+					],
+					'On False': [
+						[
+							{
+								value: false,
+							},
+						],
+					],
+				},
+			},
+		},
+	];
+
+	const nodes: INodeType[] = [new ManualTrigger(), new Code(), new Set(), new If(), new NoOp()];
+	const nodeTypes = Helpers.setup(nodes);
+
+	for (const testData of tests) {
+		test(testData.description, async () => {
+			// execute workflow
+			const { result } = await executeWorkflow(testData, nodeTypes);
+
+			// check if result node data matches expected test data
+			const resultNodeData = Helpers.getResultNodeData(result, testData);
+			resultNodeData.forEach(({ nodeName, resultData }) =>
+				expect(resultData).toEqual(testData.output.nodeData[nodeName]),
+			);
+
+			expect(result.finished).toEqual(true);
+		});
+	}
+});