feat(Default Data Loader Node): Add default text splitter (#15786)

Co-authored-by: cubic-dev-ai[bot] <191113872+cubic-dev-ai[bot]@users.noreply.github.com>

packages/@n8n/nodes-langchain/nodes/document_loaders/DocumentGithubLoader/test/DocumentGithubLoader.node.test.ts

@@ -0,0 +1,99 @@
+import { RecursiveCharacterTextSplitter } from '@langchain/textsplitters';
+import type { ISupplyDataFunctions } from 'n8n-workflow';
+import { NodeConnectionTypes } from 'n8n-workflow';
+
+import { DocumentGithubLoader } from '../DocumentGithubLoader.node';
+
+jest.mock('@langchain/textsplitters', () => ({
+	RecursiveCharacterTextSplitter: jest.fn().mockImplementation(() => ({
+		splitDocuments: jest.fn(
+			async (docs: Array<{ [key: string]: unknown }>): Promise<Array<{ [key: string]: unknown }>> =>
+				docs.map((doc) => ({ ...doc, split: true })),
+		),
+	})),
+}));
+jest.mock('@langchain/community/document_loaders/web/github', () => ({
+	GithubRepoLoader: jest.fn().mockImplementation(() => ({
+		load: jest.fn(async () => [{ pageContent: 'doc1' }, { pageContent: 'doc2' }]),
+	})),
+}));
+
+const mockLogger = { debug: jest.fn() };
+
+describe('DocumentGithubLoader', () => {
+	let loader: DocumentGithubLoader;
+
+	beforeEach(() => {
+		loader = new DocumentGithubLoader();
+		jest.clearAllMocks();
+	});
+
+	it('should supply data with recursive char text splitter', async () => {
+		const context = {
+			logger: mockLogger,
+			getNode: jest.fn(() => ({ typeVersion: 1.1 })),
+			getNodeParameter: jest.fn().mockImplementation((paramName, _itemIndex) => {
+				switch (paramName) {
+					case 'repository':
+						return 'owner/repo';
+					case 'branch':
+						return 'main';
+					case 'textSplittingMode':
+						return 'simple';
+					case 'additionalOptions':
+						return { recursive: true, ignorePaths: 'docs,tests' };
+					default:
+						return;
+				}
+			}),
+			getCredentials: jest.fn().mockResolvedValue({
+				accessToken: 'token',
+				server: 'https://api.github.com',
+			}),
+			addInputData: jest.fn(() => ({ index: 0 })),
+			addOutputData: jest.fn(),
+		} as unknown as ISupplyDataFunctions;
+		await loader.supplyData.call(context, 0);
+
+		expect(RecursiveCharacterTextSplitter).toHaveBeenCalledWith({
+			chunkSize: 1000,
+			chunkOverlap: 200,
+		});
+	});
+
+	it('should use custom text splitter when textSplittingMode is custom', async () => {
+		const customSplitter = { splitDocuments: jest.fn(async (docs) => docs) };
+		const context = {
+			logger: mockLogger,
+			getNode: jest.fn(() => ({ typeVersion: 1.1 })),
+			getNodeParameter: jest.fn().mockImplementation((paramName, _itemIndex) => {
+				switch (paramName) {
+					case 'repository':
+						return 'owner/repo';
+					case 'branch':
+						return 'main';
+					case 'textSplittingMode':
+						return 'custom';
+					case 'additionalOptions':
+						return { recursive: true, ignorePaths: 'docs,tests' };
+					default:
+						return;
+				}
+			}),
+			getCredentials: jest.fn().mockResolvedValue({
+				accessToken: 'token',
+				server: 'https://api.github.com',
+			}),
+			getInputConnectionData: jest.fn(async () => customSplitter),
+			addInputData: jest.fn(() => ({ index: 0 })),
+			addOutputData: jest.fn(),
+		} as unknown as ISupplyDataFunctions;
+		await loader.supplyData.call(context, 0);
+
+		expect(context.getInputConnectionData).toHaveBeenCalledWith(
+			NodeConnectionTypes.AiTextSplitter,
+			0,
+		);
+		expect(customSplitter.splitDocuments).toHaveBeenCalled();
+	});
+});