Add --email flag for email-gated decks

[naxIO]

Summary

• Adds --email CLI option and email= Python API parameter to support email-gated DocSend decks
• When an email gate is detected and an email is provided, the tool automatically fills in the email form and continues downloading
• Without --email, the existing EmailGateError is raised with a helpful message

Usage

docsend-dl https://docsend.com/view/XXXXXX --email user@example.com

result = asyncio.run(download_deck(
    url="https://docsend.com/view/XXXXXX",
    email="user@example.com",
))

Changes

• extractor.py: Added email parameter to extract_slide_urls(). Instead of immediately closing the browser on email gate detection, it fills in the email and clicks "Continue"
• init.py: Added email parameter passthrough in download_deck()
• cli.py: Added --email argument to the CLI parser

Test plan

• Tested with email-gated deck — successfully downloads all slides
• Public decks without email gate still work as before
• Missing --email on gated deck raises clear EmailGateError

[captivus]

Heya @naxIO! Thanks for this. Can you please add tests so that we can clearly validate the way that this works? Have a look in the tests directory for examples. I'd like to be able to clearly validate functionality of this feature via tests. Thanks!

[captivus]

@brandonmoak I see that you've forked this and have made some downstream changes to this functionality. I'd welcome your contribution and collaboration on this feature, as you've both found it useful.

I'd also welcome a PR on the folder support feature you've added. I'm keen to make this useful to as many people as possible.

https://github.com/brandonmoak/docsend-dl/tree/feat/folder-support

Thanks!

[naxIO]

Will do. It worked for me but tests is always a good idea!

[naxIO]

Done!

[jojochuang]

I checked out this PR and the feature is working for me 100%! @captivus if you'd like to merge and make a release.

[captivus]

Thanks for your patience here, and apologies for how long it's taken me to come back to this.

@jojochuang thanks as well for taking the time to check out the PR and report that the feature worked in practice for you.

The feature itself is genuinely useful, and I appreciate that you came back and added automated tests after the earlier review. The CLI/API wiring looks good, and the mocked Playwright coverage does a good job exercising the selector and submission branches.

What’s still missing for me is the validation level this repo uses for network-facing behavior. When I pointed you to the tests/ directory for examples, I wasn’t only pointing at the unit-style tests -- I was also pointing at the live integration tests against real DocSend decks in tests/test_integration.py.

So the gap here isn’t “there are no tests” -- you did add useful tests. The gap is that the tests don’t yet prove this works against the live DocSend flow in the same way the existing integration tests prove the public-deck flow.

Since this feature is specifically about email-gated decks, I’m looking for at least one integration test that exercises the full flow against a real gated deck, not only mocked Playwright objects.

If you’re up for iterating on it, I’d be glad to review a follow-up. I appreciate the contribution, and I think this would be a strong addition once the validation matches the rest of the project.