Feat(sqlmesh_dbt): Implement --model and --resource-type

[erindru]

This PR adds the -m/--model/--models argument to the sqlmesh_dbt CLI.

It does this by implementing support for the resource_type selector method in the SQLMesh selector engine and then if --models is supplied, injecting resource_type:model into the selector expression alongside the user-supplied values.

Note that --models is different to --select:

• --models just includes model nodes - so excludes seeds, sources and tests
• --select includes all nodes

[izeigerman]

Why even expose this outside this module? Why not make it a part of a single unified to_sqlmesh interface?

[erindru]

I thought about that but I wanted to keep the surface of to_sqlmesh() simple and take the minimum required parameters.

combine() still operates in dbt-land and produces consolidated selectors in dbt format. The goal is to not have to always pass down select, exclude, resource_type, models etc parameters through every layer when really all of these parameters can be described in terms of select/exclude.

So they get consolidated early to reduce the number of parameters being passed around and then the lower layers then just call to_sqlmesh() on just select / exclude and dont have to worry about or consider any of the other parameters.

You can see this in DbtOperations._plan_builder which deliberately only needs select/exclude, not all the other options that may be passed.

[themisvaltinos]

small question on the last two, what will all and default be in the sqlmesh context? I suppose this is a question for later on when multiple resource types support is added, but will these two mirror dbt as well?

[erindru]

Currently, unimplemented :) but at a guess i'd say they would be aliases for the same thing because SQLMesh includes everything by default