vdk-impala: fix impala template empty source view usr err

[mrMoZ1]

what: The template arguments validator now makes use of the skip_remaining_steps() method when an empty source view is returned.

why: Users of the template requested that empty source view stopped resulting in a User Error, after a discussion it was agreed that this is the correct and desired behaviour.

testing: this change depends on #1188
Edited failing regression tests.

Signed-off-by: Momchil Zhivkov mzhivkov@vmware.com

[antoniivanov]

I will never tire asking this :) Tests ?

Any bug we fix should have tests. I am surprised that no tests fail (clearly we have not added tests covering this scenario - what happens if SQL view returns 0 rows) but now it's a good opportunity to do so

[mrMoZ1]

I will never tire asking this :) Tests ?

Any bug we fix should have tests. I am surprised that no tests fail (clearly we have not added tests covering this scenario - what happens if SQL view returns 0 rows) but now it's a good opportunity to do so

Tests will likely fail. And I will update the MR accordingly.

[antoniivanov]

Some small comment around test verification but looks good to me. Thanks.

[antoniivanov]

I know it's merged but I am leaving the comment for future reference (we can leave it now this way) :

There's util cli_assert (https://github.com/vmware/versatile-data-kit/blob/main/projects/vdk-plugins/vdk-test-utils/src/vdk/plugin/test_utils/util_funcs.py#L53) utility that should be used, It prints a lot of more details about the execution if the assert fails.