adding date() and datetime() short hand macros

[gregology]

Problem

It takes a lot of Jinja boilerplate to generate simple datetime objects.

{% set foo = modules.datetime.datetime(1997, 9, 29, 6, 14, tzinfo=modules.pytz.timezone('UTC')) %}

Compiles as 1997-09-29 06:14:00+00:00

Solution

The PR introduces datetime() and date() macros to reduce boilerplate and increase code readability.

{% set foo = dbt_date.datetime(1997, 9, 29, 6, 14) %}

Compiles as 1997-09-29 06:14:00+00:00

This halves the character count to produce a datetime object.

The datetime() macro defaults to timezone from the dbt_date:time_zone project variable.

The date() macro doesn't reduce the Jinja boilerplate as much but it is useful for consistency.

{% set foo = dbt_date.date(1997, 9, 29) %}

Compiles as 1997-09-29

[clausherther]

Hi @gregology - sorry for the late reply! This sounds like a really good idea, thanks! Any way we can add this to one of the integration tests so we can make sure these macros are covered?

[gregology]

Cheers @clausherther! Is this testing pattern suitable?

[clausherther]

@gregology pushed a couple of changes to get tests to pass. The return value of the macro has to be a string, also there is no millisecond argument on datetime, but there is microsecond 🤷
Also, added a param for tz in case folks want to override for each call.
Let me know what you think!

[gregology]

Good call on the tz param and good catch on the missing millisecond argument 👍

I have refactored the macros to output date & datetime objects using casting in the tests. Our use case for this is mainly in testing where Pythonic syntax for datetime manipulation can be more readable.

Is this test coverage and pattern suitable?

[clausherther]

Looks good, thanks!

[clausherther]

@gregology sorry, one last thing please: could we add these to the bottom of the README, maybe after Fiscal Calendar (and add them to the top index)? Even though they're utility macros, we're expecting folks to use them directly. Particularly, the fact that they don't return strings will trip up people and I'm sure we'll get questions/PRs to convert them. So, a README entry could head that off. Thanks!

[gregology]

Good point @clausherther, I have updated the README to document the macros and included reasoning for outputting a date / datetime object. Also, nice use of the anchor links 👍 Thanks for your patience and awesome tool mate!

[clausherther]

I'll cut a release later today. Thanks!