[Feature] Add e2e tests for Node.js package

[ASHUTOSH-KUMAR-RAO]

Problem Statement

The Node.js package currently has zero test coverage.
While the Python package has well-structured e2e tests:

• test_parse_e2e.py
• test_batch_e2e.py
• test_screenshot_e2e.py

The Node.js package has none, which makes it difficult to:

• Catch regressions after updates
• Verify correct parsing behavior
• Ensure reliability for Node.js users

Proposed Solution

Add equivalent e2e tests in TypeScript for the Node.js
package, covering:

1. Basic parsing — parse a sample document and verify output
2. Batch parsing — parse multiple documents simultaneously
3. Screenshot parsing — verify image/screenshot parsing

I have experience with TypeScript and have already
contributed to LlamaIndex core. I'm happy to implement
this if the team is open to it!

Alternatives Considered

No response

Additional Context

No response

[logan-markewich]

Technically CICD and releases do a smoke test with the CLI, so at least basic parsing is covered

[ASHUTOSH-KUMAR-RAO]

Thanks for the context, Logan!

Good to know basic parsing is covered via CI/CD smoke tests.

Would it be valuable to add more granular unit tests
for edge cases like malformed inputs, large documents,
or specific file types? Happy to contribute if there's
a gap worth filling!