t-youtube-transcript-fetcher/dist/src/__tests__/proxy.test.js

An enhanced TypeScript library for fetching YouTube transcripts with proxy support (based on youtube-transcript)

import { jest } from '@jest/globals';
// Set up mocks before importing modules that use them
const mockFetch = jest.fn();
const mockHttpsProxyAgent = jest.fn().mockImplementation(() => ({
    // Mock proxy agent instance
    constructor: { name: 'HttpsProxyAgent' }
}));
jest.unstable_mockModule('node-fetch', () => ({
    default: mockFetch
}));
jest.unstable_mockModule('https-proxy-agent', () => ({
    HttpsProxyAgent: mockHttpsProxyAgent
}));
// Import after setting up mocks
const { YoutubeTranscript } = await import('../transcript.js');
describe('Proxy Configuration', () => {
    const validVideoId = 'dQw4w9WgXcQ';
    const mockCaptionsData = {
        playerCaptionsTracklistRenderer: {
            captionTracks: [
                {
                    baseUrl: 'https://youtube.com/api/timedtext',
                    languageCode: 'en'
                }
            ]
        }
    };
    beforeEach(() => {
        jest.clearAllMocks();
        mockFetch.mockImplementation(() => Promise.resolve({
            text: () => Promise.resolve(`"captions":${JSON.stringify(mockCaptionsData)},"videoDetails"`),
            ok: true
        }));
    });
    it('should use provided proxy configuration', async () => {
        const proxyConfig = {
            host: 'http://proxy.example.com:8080',
            auth: {
                username: 'user',
                password: 'pass'
            }
        };
        await YoutubeTranscript.fetchTranscript(validVideoId, { proxy: proxyConfig });
        expect(mockHttpsProxyAgent).toHaveBeenCalledWith(expect.stringContaining('user:pass@proxy.example.com:8080'));
        expect(mockFetch).toHaveBeenCalledWith(expect.any(String), expect.objectContaining({
            agent: expect.objectContaining({ constructor: { name: 'HttpsProxyAgent' } })
        }));
    });
    it('should use proxy without authentication', async () => {
        const proxyConfig = {
            host: 'http://proxy.example.com:8080'
        };
        await YoutubeTranscript.fetchTranscript(validVideoId, { proxy: proxyConfig });
        expect(mockHttpsProxyAgent).toHaveBeenCalledWith(expect.stringContaining('proxy.example.com:8080'));
    });
    it('should use pre-configured proxy agent', async () => {
        const mockProxyAgent = mockHttpsProxyAgent('http://proxy.example.com:8080');
        await YoutubeTranscript.fetchTranscript(validVideoId, { proxyAgent: mockProxyAgent });
        expect(mockFetch).toHaveBeenCalledWith(expect.any(String), expect.objectContaining({
            agent: mockProxyAgent
        }));
    });
    it('should make request without proxy when no proxy config provided', async () => {
        await YoutubeTranscript.fetchTranscript(validVideoId);
        expect(mockHttpsProxyAgent).not.toHaveBeenCalled();
        expect(mockFetch).toHaveBeenCalledWith(expect.any(String), expect.not.objectContaining({
            agent: expect.objectContaining({ constructor: { name: 'HttpsProxyAgent' } })
        }));
    });
});