feat: handle tests for WATCHER_KUBERNETES mode

[vricciardulli]

Description

Following #2441 and #2447, this PR implements test handling for WATCHER_KUBERNETES mode.

Related Issue(s)

closes #2427

Breaking Change?

Checklist

• I have made corresponding changes to the documentation (if required)
• I have added tests that prove my fix is effective or that my feature works

[Copilot]

Pull request overview

Implements dbt test handling for ExecutionMode.WATCHER_KUBERNETES by turning the previously-placeholder test operator into a watcher sensor and updating docs/tests to reflect the supported TestBehavior options in this mode.

Changes:

• Implement DbtTestWatcherKubernetesOperator as a DbtConsumerWatcherKubernetesSensor that watches aggregated test results via XCom.
• Add/adjust unit and graph-construction tests to cover watcher-kubernetes test behavior (NONE, AFTER_EACH, AFTER_ALL).
• Update watcher and watcher-kubernetes documentation to describe the supported test behaviors and operators.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
cosmos/operators/watcher_kubernetes.py	Replaces placeholder test operator with a real watcher sensor implementation.
tests/operators/test_watcher_kubernetes_unit.py	Adds unit tests for the new test watcher sensor; simplifies producer callback test.
tests/airflow/test_graph.py	Verifies task generation for watcher-kubernetes across TestBehavior modes.
docs/guides/run_dbt/container/watcher-kubernetes-execution-mode.rst	Updates limitations/behavior docs to reflect test support in watcher-kubernetes.
docs/guides/run_dbt/airflow-worker/watcher-execution-mode.rst	Updates watcher-mode test behavior documentation to match current behavior.

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[tatiana]

Thank you very much @vricciardulli , this looks great!

[michal-mrazek]

Awesome, thanks! :)

[pankajkoti]

Not sure if it's due to this PR, but it's evident on the merge of this PR, that the kubernetes tests are getting stuck https://github.com/astronomer/astronomer-cosmos/actions/runs/24081355329/job/70242570483

[tatiana]

@vricciardulli @michal-mrazek we unfortunately had to revert (#2535) this PR since it caused the K8S integration tests to get stuck for some reason, and we do not have time to fix it right now. I made the mistake of merging it without realising that those tests were stuck.

@pankajkoti created a PR to revert. Please, if you could open a new PR with the change and fix the integration tests - we can make sure this will be shipped as part of Cosmos 1.15.0.

[vricciardulli]

@tatiana sorry for the inconvenience!

[tatiana]

@vricciardulli don't worry, it was my fault - I should have realised the tests weren't running as expected, and that would have avoided this situation.

It would be amazing if you could create a new PR with the feature, and we could support on checking what may be hanging. Did you test the feature locally, using Airflow standalone or some other way?

[vricciardulli]

@tatiana I've opened the PR again #2543

I only ran unit tests locally, I wasn't yet able to set up integration tests locally so I thought I'd wait for the CI to run them instead.