Return full Postmark API response from send() and add tests

[mymah01]

Summary

This PR updates PMMail.send() and PMBatchMail.send() to return the parsed JSON response from the Postmark API instead of only True/False.

This makes it possible for client code to access useful details such as MessageID, ErrorCode, and Message without re-calling the API.

Changes

Updated PMMail.send() to return the JSON object from Postmark.
Updated PMBatchMail.send() to return a list of JSON objects (one per message).
Updated unit tests to cover both single and batch send scenarios, mocking urlopen to simulate Postmark responses.

Motivation

The previous implementation returned only a boolean, which limited insight into failures or response metadata. Returning the full response allows better error handling and logging.

Example

mail = PMMail(
    api_key="test-api-key",
    sender="sender@example.com",
    to="receiver@example.com",
    subject="Hello",
    text_body="Testing single mail return",
)
result = mail.send()
print(result["MessageID"])  # now accessible

Tests

✅ test_mail_returns_result added for PMMail
✅ test_batch_mail_returns_results added for PMBatchMail

[nicholasserra]

Thanks! I like it. We'll probably just need to bump the major version on this package, as there's likely people checking that boolean response on send. Will think on it a bit.

[mymah01]

Awesome, another option would be to add a check, or allow for an opt-in, i.e.:

return_json = False
return parsed if return_json else True
return results if return_json else True

then in mail.send()
we can have: mail.send(return_json=True)

[mymah01]

I can update to reflect proposed changes that cater for previous usage as well.

[nicholasserra]

I think the new change is good. Looks like tests might be broken upstream. Also I think your tests will need updated with the new changes. I'm gonna peek the test suite in master and we'll go from there. Thanks!

[nicholasserra]

Confirmed tests are fine in master. Looks like they're broken in here. Adding some comments on the diff.

[nicholasserra]

LGTM thanks! I'll bump and do a release