[Unit Testing] Add functional tests for unit testing:

[MichelleArk]

Is this your first time submitting a feature request?

• I have read the expectations for open source contributors
• I have searched the existing issues, and I could not find an existing issue for this feature
• I am requesting a straightforward extension of existing dbt-spark functionality, rather than a Big Idea better suited to a discussion

Describe the feature

Add spark-specific tests that implement the 3 base unit testing functional tests:

1. BaseUnitTestingTypes
   • Core issue: case insensitive column names for unit test YML  dbt-core#9467
   • Currently, the unit testing framework in core uses the safe_cast utils macro to convert a user-provided value for an input mock to the appropriate type. In some instances, this safe_cast may fail and need special handling depending on the type.
   • The acceptance criteria for this issue is to introduce a test that provides coverage across all primative input types (and arrays & objects if possible!) for unit testing input data, potentially updating the safe_cast macro as necessary.
2. BaseUnitTestCaseInsensivity
3. TestSparkUnitTestInvalidInput

Describe alternatives you've considered

n/a

Who will this benefit?

dbt users of dbt-spark or adapters that extend dbt-spark :)

Are you interested in contributing this feature?

yep!

Anything else?

N/A

[MichelleArk]

Resolved by: #976