[Feature] Automatically set --event-start-time and --event-end-time values if not provided

[QMalcolm]

Housekeeping

• I am a maintainer of dbt-core

Short description

In #10624 we're building a new type of incremental model strategy, microbatch. In #10635 we allowed people to specify event_time_start and event_time_end via the CLI. However, the more common situation will be that neither are specified (or perhaps only one of them is specified).

In the case where event_time_end isn't specified, then the value of event_time_end should become now. In the case where event_time_start isn't specified, then the value of event_time_start should become the value of event_time_end truncated to the start of the batch_size definition.

In the case where neither is specified, what is listed above still applies. That is to say that if now is 2024-09-04 13:11:00 and my batch_size is day, then event_time_end would be 2024-09-04 13:11:00 and event_time_start would be 2024-09-04 00:00:00.

Acceptance criteria

• event_time_end and event_time_start provided from the CLI is preferred
• if event_time_end is not specified, then the value of event_time_end becomes now
• if event_time_start is not specified, then the value of event_time_start becomes event_time_end truncated by the batch_size

Suggested Tests

1. Values of event_time_end and event_time_end provided from the CLI are preffered
2. If event_time_end is not provided, it is correctly defaulted
3. If event_time_start is not provided it is correctly defaulted

Impact to Other Teams

N/A

Will backports be required?

No

Context

Depends on:

• [Feature] --event-start-time and --event-end-time as CLI flags for specifying microbatch start and end times #10635
• [Feature] Allow setting of batch_size as a top-level property of a model #10637

[QMalcolm]

Resolved by #10594