[CT-3146] [Implementation] updating the unit-tests block (to start with test name instead of model)

[graciegoheen]

Housekeeping

• I am a maintainer of dbt-core

Short description

From #8606

Current the unit test spec is as follows:

unit:
  - model: my_model # name of the model I'm unit testing
    tests:
     - name: test_is_valid_email_address # this is the unique name of the test
       given: # optional: list of inputs to provide as fixtures
        - input: ref('users')
          rows:
           - {user_id: 1, email: cool@example.com,     email_top_level_domain: example.com}
           - {user_id: 2, email: cool@unknown.com,     email_top_level_domain: unknown.com}
           - {user_id: 3, email: badgmail.com,         email_top_level_domain: gmail.com}
           - {user_id: 4, email: missingdot@gmailcom,  email_top_level_domain: gmail.com}
         - input: ref('top_level_domains')
           rows:
            - {tld: example.com}
            - {tld: gmail.com}
       expect: # required: the expected output given the inputs above
        - {user_id: 1, is_valid_email_address: true}
        - {user_id: 2, is_valid_email_address: false}
        - {user_id: 3, is_valid_email_address: false}
        - {user_id: 4, is_valid_email_address: false}
    - name: test_another_column
      ...

we should adjust it so that the block is

1. named unit-tests: instead of unit:
2. starts with the test name instead of the model name

the final spec should look like this:

unit-tests:
  - name: test_is_valid_email_address # this is the unique name of the test
    model: my_model # name of the model I'm unit testing
    given: # optional: list of inputs to provide as fixtures
      - input: ref('users')
        rows:
         - {user_id: 1, email: cool@example.com,     email_top_level_domain: example.com}
         - {user_id: 2, email: cool@unknown.com,     email_top_level_domain: unknown.com}
         - {user_id: 3, email: badgmail.com,         email_top_level_domain: gmail.com}
         - {user_id: 4, email: missingdot@gmailcom,  email_top_level_domain: gmail.com}
      - input: ref('top_level_domains')
        rows:
         - {tld: example.com}
         - {tld: gmail.com}
    expect: # required: the expected output given the inputs above
      - {user_id: 1, is_valid_email_address: true}
      - {user_id: 2, is_valid_email_address: false}
      - {user_id: 3, is_valid_email_address: false}
      - {user_id: 4, is_valid_email_address: false}
  - name: test_another_column
    ...

Acceptance criteria

• unit test block is called unit-tests:
• unit test block starts with test name (instead of model name)

Impact to Other Teams

None

Will backports be required?

No

Context

No response

[graciegoheen]

• changes the hierarchy, which will affect parsing
• already storing by the unit test in the manifest → so no expected manifest structure changes

[emmyoop]

Resolved by #8988 and #8966