Guidance on writing testing plans and where to include them in the process

[ptomato]

We'd like to encourage proposal champions to write testing plans as part of the process of moving proposals into stage 2.7.

Currently, testing plans are not written very often, and primarily by the test262 maintainers. However, proposal champions are often in a better position to write these, given a more detailed understanding the ins and outs of proposals. The maintainers can then give feedback on these testing plans.

We'd like to provide guidance for the community on writing a testing plan. Once that is written, we can notify people about it in the following plenary, and request that champions help with the testing plans once a proposal reaches stage 2.7. Depending on the response to this, and how well it works, we could consider making it part of the stage process.

@jugglinmike wrote a guide for WPT: http://web-platform-tests.org/writing-tests/making-a-testing-plan.html

h/t @romulocintra for the original idea.

[bakkot]

I've tried to make such plans in e.g. #3738 and #3828 and having concrete guidance would be great.

Regarding the stage process, we could certainly have it called out as an action item for proposal champions upon reaching 2.7, the same way that a call for reviewers is an action item for champions upon reaching stage 2. And I think it would be nice to have a link to "a summary of the tests" (or something) be a part of the required materials for stage 3, which could be met by a link to the test plan: it is much easier to review completeness of something which describes what is to be tested, rather than the full PR or PRs containing those tests.