Add browser coverage for human-readable routes

[snowyukitty]

Type of Change

• Tests: Add route-adjacent Playwright coverage for the human-readable API and library-version routes.
• Something else: Install the lockfile-matched Playwright Chromium build and run the browser suite in CI.

What issue does this relate to?

Fixes #188

What should this PR do?

• Start a local Worker from a worker-scoped @playwright/test server fixture using Wrangler's createTestHarness(), and reset the harness after each test.
• Use the harness's dynamically allocated loopback URL as Playwright's baseURL and navigate directly to /api and /libraries/backbone.js/1.1.0.
• Configure WEBSITE_BASE for the dynamic local origin according to the Worker's prefix-based website detection.
• Assert the hydrated API documentation and library file filter with native Playwright locators and assertions.
• Keep browser coverage beside the corresponding route specs.
• Avoid a Vite browser-test server, reverse proxy, iframe, and external API-origin inheritance.

What are the acceptance criteria?

• npm test
• npm run test:browser
• npm run lint
• npm run types
• npm run format
• npx wrangler deploy --dry-run

This changes test infrastructure and coverage only; it does not change production behavior or the rendered UI, so before/after screenshots are not applicable.

[MattIPv4]

Thanks for working on this! Instead of unstable_dev, I wonder if we can use the new createTestHarness designed for use w/ Playwright etc.? https://developers.cloudflare.com/changelog/post/2026-07-21-integration-test-harness/

[snowyukitty]

Addressed both suggestions: the browser suite now uses createTestHarness(), and the assertions live in route-adjacent api.browser.spec.ts and library.browser.spec.ts files. I also incorporated current master (through #261) and kept the browser setup aligned with the WEBSITE_BASE route contract.

Fresh current-base checks pass: Chromium 2/2 twice, unit tests 485/485, types, lint, focused formatting, a Wrangler dry run, and git diff --check. Thanks!

[Copilot]

Pull request overview

Adds real-browser coverage for human-readable routes through a local Worker and Vite proxy, plus cross-platform island bundling support.

Changes:

• Adds Playwright browser tests for API documentation and library filtering.
• Configures local Worker lifecycle, proxying, and dynamic ports.
• Normalizes Vite paths and runs browser tests in CI.

Reviewed changes

Copilot reviewed 9 out of 10 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
vitest.config.ts	Excludes browser specs from unit tests.
vitest.browser.setup.ts	Manages the browser-test Worker lifecycle.
vitest.browser.config.ts	Configures Playwright, proxying, and ports.
vite.client.config.ts	Normalizes island module paths.
src/utils/spec/browser.ts	Provides the iframe route helper.
src/routes/library.browser.spec.ts	Tests library-page hydration and filtering.
src/routes/api.browser.spec.ts	Tests hydrated API documentation.
package.json	Adds browser tooling and test command.
package-lock.json	Locks new browser dependencies.
.github/workflows/ci.yml	Installs Chromium and runs browser tests.

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

[MattIPv4]

👋 Thanks for getting this updated. Having explored this more locally, and how the proxy that Vite provides works, I'm a bit concerned by the security model here as we do testing of remote origins in our CI -- it seems it would be possible for a remote origin we're testing to use the Vite proxy to access files on disk etc.

I wonder if we'd be better off using regular ol' Playwright? I think the setup would be similar using createTestHarness, but wouldn't need the proxy setup nor the iframe, as we'd be able to hit the local/remote worker URL via direct page navigation?

[MattIPv4]

Thank you!