UX improvements to model versions

[jtcohen6]

resolves #7443

Naive implementations for some of the proposed improvements I mention here:

• Model versions #6736 (comment)

Overview of changes

1. By default, land the latest_version of dim_customers in <db>.<schema>.dim_customers (no suffix). This is a behavior change to the built-in generate_alias_name, so if we're going to do it, we should do it before the final release. We are going to recommend accomplishing this with a post-hook in the meantime. We are still discussing if it makes sense to vendor that macro code within dbt-core.
2. By default, allow defining the latest_version of dim_customers in a file named dim_customers.sql (no suffix). The convention of dim_customers_vX.sql would also be supported — so this isn't actually a behavior change.
3. Info-level log if you have an unpinned ref to a model that has a newer-than-latest (i.e. prerelease) version defined: "Heads up, your unpinned ref will roll over to the new version as soon as it's the latest." (Should this be a warning? If you're not actually referencing a model slated for deprecation...)

11:47:08  3 of 3 START sql view model dbt_jcohen.another_model ........................... [RUN]
11:47:09  While compiling 'another_model':
Found an unpinned reference to versioned model 'my_model' in 'my_dbt_project'.
Resolving to latest version: my_model.v2
A prerelease version 3 is available. It has not yet been marked 'latest' by its maintainer.
When that happens, this reference will resolve to my_model.v3 instead.

  Try out v3: {{ ref('my_dbt_project', 'my_model', v='3') }}
  Pin to v2:  {{ ref('my_dbt_project', 'my_model', v='2') }}

(Bonus) Raise a nicer error if I've written a ref pinned to a specific version, and the model I'm referencing isn't actually versioned. This came up during training, when someone didn't correctly define the versions block on their model — but it wasn't clear if the error was in the model configuration, or in the downstream ref. This isn't a behavior change, and the codepath is slightly trickier, so I'll probably just kick it out of this PR. Update: Kicked out of scope.

Checklist

• I have read the contributing guide and understand what's expected of me
• I have signed the CLA
• I have run this code in development and it appears to resolve the stated issue
• This PR includes tests, or tests are not required/relevant for this PR — no test for the logging event
• I have opened an issue to add/update docs, or docs changes are not required/relevant for this PR — captured in Revisions & additions to Model Versions docs.getdbt.com#3232
• I have run changie new to create a changelog entry

[github-actions]

Thank you for your pull request! We could not find a changelog entry for this change. For details on how to document a change, see the contributing guide.

[jtcohen6]

Holding off on merging until the outcome of this slack thread, wherein we decide whether to vendor create_latest_version_view within dbt-core directly. I'm leaning toward yes; I'd want to add another test for this.

Update: Let's opt for, this will come in v1.6; in the meantime, a macro you can copy-paste-edit-post-hook.

[MichelleArk]

think this can be simplified to:

max_version: Union[str, float, None] = max(  # type: ignore
  [v.version for v in manifest.nodes.values() if v.name == node.name]
)

[jtcohen6]

this is ... clearly better

[MichelleArk]

Broader refactoring suggestion: using UnparsedVersion for the comparisons, similar to what we do in the graph selector method here

                max_version = max(
                    [
                        UnparsedVersion(v.version)
                        for v in manifest.nodes.values()
                        if v.name == node.name and v.version is not None
                    ]
                )
                assert node.latest_version
                if max_version > UnparsedVersion(node.latest_version):
                    fire_event(
                        UnpinnedRefNewVersionAvailable(
                            node_info=get_node_info(),
                            ref_node_name=node.name,
                            ref_node_package=node.package_name,
                            ref_node_version=str(node.version),
                            ref_max_version=str(max_version.v),
                        )
                    )

The TypeError issues in unit testing should be fixed by updating the MockNode constructor:

+++ b/test/unit/utils.py
@@ -350,6 +350,7 @@ def MockNode(package, name, resource_type=None, **kwargs):
         **kwargs,
     )
     node.name = name
+    node.is_versioned = resource_type is NodeType.Model and version is not None
     return node

[jtcohen6]

yes!!!

[jtcohen6]

at the risk of expanding the intended scope of a partial parsing test - I'm going to borrow your commit 84cc3ca and check that this message is being logged in the case of an unpinned ref to a latest-not-newest model

[MichelleArk]

Looking at the logged message:

Try out v3: {{ ref('my_dbt_project', 'my_model', v='3') }}
Pin to v2:  {{ ref('my_dbt_project', 'my_model', v='3') }}

Should the second line be:

Pin to v2:  {{ ref('my_dbt_project', 'my_model', v='2') }}

[jtcohen6]

Will rebase after #7439 is merged