fix: Set CRON trigger fields

[WillDaSilva]

Changes

Fixes #923

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* Fix big bad boo-boo in the async scheduler (#999 <https://github.com/agronholm/apscheduler/issues/999>_; PR by @yourgithubaccount)

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[agronholm]

The proper fix would be to override __init__() to accept the individual fields, and call __attrs_init__() to fill in the fields we want to keep, and then fill in the _fields attribute. A test that fails without the fix would also be required.

[WillDaSilva]

A test that fails without the fix would also be required.

Yup. I plan to add one before I mark this as ready for review.

fill in the fields we want to keep

@agronholm I'm not sure what you mean by this. Don't we want to keep all of the fields? Specifically, that is:

• year
• month
• day
• week
• day_of_week
• hour
• minute
• second
• start_time
• end_time
• timezone
• last_fire_time

If you feel you know how to fix it, and that fixing it yourself would be easier than helping me fix it, feel free to take it away. Otherwise I'm happy to see this through. Whatever's easiest for you.

[agronholm]

The initializer parameters from year to second were only supposed to be used to fill out the appropriate fields, and should not be stored in the instance. That this happened was an artifact of the class being transformed into an attrs class. Before I started using attrs in APScheduler, I had intended these to be InitVars when the trigger class was going to be a data class, but attrs does not have such a feature. Instead, its docs recommend overriding __init__(). I'll see about doing this tomorrow.

[agronholm]

Closing in favor of commit 0240dce.