domain project / streaming

Video Streaming

Test strategies for content catalogues, video playback, DRM, subscription management, and adaptive bitrate streaming.

Content catalogue & searchVideo playbackSubscription & billingDRM & access controlAdaptive bitrateWatch history & recommendations

Domain Overview

Video streaming platforms must guarantee playback continuity, enforce content licensing through DRM, and gate premium content behind subscriptions. Testing spans CDN-delivered manifests, browser-native media APIs, licence server integrations, and billing lifecycle edge cases.

Typical stack: React / Web Components player, HLS/DASH manifest via CDN, Widevine/FairPlay DRM licence server, Stripe subscription billing, recommendation microservice.

Key Test Areas

Area	What to test	Risk
Catalogue	Search, browse, genre filters, series/episode structure, metadata accuracy	User can’t find content
Playback	Play/pause/seek, quality switching, captions/subtitles, autoplay next episode	Black screen, spinner loop
Auth & access	Subscription gates, free vs premium content, concurrent device limits	Unauthorised access, paying user blocked
DRM	Valid licence loads, error on expired/invalid licence, offline download licence	Content pirates, legitimate user errors
Billing	Free trial, subscription start, cancellation, invoice generation, card update	Surprise charges, failed renewals
Recommendations	Personalised row appears, no crash when watch history is empty	Broken homepage for new users

Test Pyramid for Video Streaming

Unit (60%):   Manifest URL builder, DRM key-system selection, billing proration logic
Integration (30%): Licence server handshake, billing webhook handler, catalogue search API
E2E (10%):    Login → browse catalogue → play video → verify captions → autoplay next

Critical E2E tests (must pass before every deploy):

Premium content is accessible to subscribed user and blocked for free user
Video player plays and seek to 30s works without buffering loop
Captions toggle on/off and track language can be changed
Subscription cancellation stops renewal charge
New user homepage renders without watch history (no crash)

Common Failure Scenarios

1. Video player shows spinner forever when stream URL returns 403
   Test: intercept manifest URL with page.route(), return 403, assert error message visible not infinite spinner

2. Subtitle timing offset after seek
   Test: seek to 00:01:30, wait for caption element, assert caption text matches expected line for that timestamp

3. Concurrent device limit not enforced
   Test: open same account in two browser contexts, play in both, assert second context receives device-limit error

4. Trial cancellation still charges card at period end
   Test: mock billing webhook for trial_end event after cancellation, assert no invoice created

5. Autoplay doesn't trigger for next episode when DRM licence not pre-fetched
   Test: let episode end, intercept licence request timing, assert next episode starts within 3s

Playwright Patterns for Video Streaming

// Intercept manifest, return 403, verify player shows error not spinner
test('player shows error message on 403 manifest', async ({ page }) => {
  await page.route('**/*.m3u8', route => route.fulfill({ status: 403 }));
  await page.goto('/watch/episode-1');
  await page.getByRole('button', { name: 'Play' }).click();
  // Error message must appear; spinner must not persist
  await expect(page.getByTestId('player-error')).toBeVisible({ timeout: 5000 });
  await expect(page.getByTestId('player-spinner')).toBeHidden();
});

// Captions toggle via accessible role
test('captions can be toggled on and off', async ({ page }) => {
  await page.goto('/watch/episode-1');
  await page.getByRole('button', { name: 'Play' }).click();
  const captionsBtn = page.getByRole('button', { name: /captions/i });
  await captionsBtn.click();
  await expect(page.getByTestId('caption-track')).toBeVisible();
  await captionsBtn.click();
  await expect(page.getByTestId('caption-track')).toBeHidden();
});