Gradually increasing standards for Testing

[laceysanderson]

The @tripal/project-managent-commitee-pmc recently had a conversation about testing standards for Tripal 4. This issue summarizes the decisions that have come about from that discussion. Additionally, it will act as a launching point for adding these standards into the documentation and for increasing guidance on testing in general.

Requirement for Tripal 4:

A PR should not reduce the overall test coverage of the repository.

PRs are testing for code coverage by code climate and once that Github Action is complete you will get a comment like the following:

As you can see based on the green box in the above screenshot, this PR follows the requirement above in that it did not decrease the total coverage in the repository.

Context:

• Automated testing is critical for keeping up with Drupal version compatibility as it's the most reliable way to detect deprecation notices before they are removed.
• We are making a substantial push towards this in Tripal 4 and are working towards a high level of test coverage.
• We need to balance the need for automated testing with the need to get a new version of Tripal 4 out as soon as possible. Good testing can take a fair amount of time/effort to develop.
• We want to ensure that our development practices don't reduce our existing test coverage as this is very discouraging to those developing tests and is counterproductive towards our goals.