refactor(Code Node): Constently handle various kinds of data returned by user code (#6002)

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

@@ -1,5 +1,136 @@
+import { anyNumber, mock } from 'jest-mock-extended';
+import type { IExecuteFunctions, IWorkflowDataProxyData } from 'n8n-workflow';
+import { NodeHelpers } from 'n8n-workflow';
+import { normalizeItems } from 'n8n-core';
 import { testWorkflows, getWorkflowFilenames } from '../../../test/nodes/Helpers';
+import { Code } from '../Code.node';
+import { Sandbox } from '../Sandbox';
+import { ValidationError } from '../ValidationError';
 
 const workflows = getWorkflowFilenames(__dirname);
 
 describe('Test Code Node', () => testWorkflows(workflows));
+
+describe('Code Node unit test', () => {
+	const node = new Code();
+	const thisArg = mock<IExecuteFunctions>({
+		helpers: { normalizeItems },
+		prepareOutputData: NodeHelpers.prepareOutputData,
+	});
+	const workflowDataProxy = mock<IWorkflowDataProxyData>({ $input: mock() });
+	thisArg.getWorkflowDataProxy.mockReturnValue(workflowDataProxy);
+
+	describe('runOnceForAllItems', () => {
+		beforeEach(() => {
+			thisArg.getNodeParameter.calledWith('mode', 0).mockReturnValueOnce('runOnceForAllItems');
+		});
+
+		describe('valid return data', () => {
+			const tests: Record<string, [object | null, object]> = {
+				'should handle null': [null, []],
+				'should handle pre-normalized result': [
+					[{ json: { count: 42 } }],
+					[{ json: { count: 42 } }],
+				],
+				'should handle when returned data is not an array': [
+					{ json: { count: 42 } },
+					[{ json: { count: 42 } }],
+				],
+				'should handle when returned data is an array with items missing `json` key': [
+					[{ count: 42 }],
+					[{ json: { count: 42 } }],
+				],
+				'should handle when returned data missing `json` key': [
+					{ count: 42 },
+					[{ json: { count: 42 } }],
+				],
+			};
+
+			Object.entries(tests).forEach(([title, [input, expected]]) =>
+				test(title, async () => {
+					jest.spyOn(Sandbox.prototype, 'run').mockResolvedValueOnce(input);
+
+					const output = await node.execute.call(thisArg);
+					expect(output).toEqual([expected]);
+				}),
+			);
+		});
+
+		describe('invalid return data', () => {
+			const tests = {
+				undefined,
+				null: null,
+				date: new Date(),
+				string: 'string',
+				boolean: true,
+				array: [],
+			};
+
+			Object.entries(tests).forEach(([title, returnData]) =>
+				test(`return error if \`.json\` is ${title}`, async () => {
+					jest.spyOn(Sandbox.prototype, 'run').mockResolvedValueOnce([{ json: returnData }]);
+
+					try {
+						await node.execute.call(thisArg);
+						throw new Error("Validation error wasn't thrown");
+					} catch (error) {
+						expect(error).toBeInstanceOf(ValidationError);
+						expect(error.message).toEqual("A 'json' property isn't an object");
+					}
+				}),
+			);
+		});
+	});
+
+	describe('runOnceForEachItem', () => {
+		beforeEach(() => {
+			thisArg.getNodeParameter.calledWith('mode', 0).mockReturnValueOnce('runOnceForEachItem');
+			thisArg.getNodeParameter.calledWith('jsCode', anyNumber()).mockReturnValueOnce('');
+			thisArg.getInputData.mockReturnValueOnce([{ json: {} }]);
+		});
+
+		describe('valid return data', () => {
+			const tests: Record<string, [object | null, { json: any } | null]> = {
+				'should handle pre-normalized result': [{ json: { count: 42 } }, { json: { count: 42 } }],
+				'should handle when returned data missing `json` key': [
+					{ count: 42 },
+					{ json: { count: 42 } },
+				],
+			};
+
+			Object.entries(tests).forEach(([title, [input, expected]]) =>
+				test(title, async () => {
+					jest.spyOn(Sandbox.prototype, 'run').mockResolvedValueOnce(input);
+
+					const output = await node.execute.call(thisArg);
+					expect(output).toEqual([[{ json: expected?.json, pairedItem: { item: 0 } }]]);
+				}),
+			);
+		});
+
+		describe('invalid return data', () => {
+			const tests = {
+				undefined,
+				null: null,
+				date: new Date(),
+				string: 'string',
+				boolean: true,
+				array: [],
+			};
+
+			Object.entries(tests).forEach(([title, returnData]) =>
+				test(`return error if \`.json\` is ${title}`, async () => {
+					jest.spyOn(Sandbox.prototype, 'run').mockResolvedValueOnce({ json: returnData });
+
+					try {
+						await node.execute.call(thisArg);
+						throw new Error("Validation error wasn't thrown");
+					} catch (error) {
+						expect(error).toBeInstanceOf(ValidationError);
+						expect(error.message).toEqual("A 'json' property isn't an object [item 0]");
+					}
+				}),
+			);
+		});
+	});
+});