Replace the community_summary view by a table

[Changaco]

Fixes #2693 without reverting back to using slow queries.

[chadwhitacre]

Does the test suite already cover this?

[chadwhitacre]

If not let's get some tests.

[Changaco]

The test coverage of gratipay/models/community.py is currently 88%.

[chadwhitacre]

How do we measure test coverage of SQL functions?

[Changaco]

We don't, it would probably be very difficult.

[chadwhitacre]

Okay, short of measuring coverage of SQL functions, how do we test SQL functions?

[chadwhitacre]

I like the idea of using more SQL functions and triggers, but I'm concerned about testing.

[Changaco]

Like all functions, by writing tests that run them.

[chadwhitacre]

Bringing us back to my original question:

Does the test suite already cover this?

[Changaco]

The trigger function in this PR is used and checked in branch.sql itself.

[Changaco]

In addition the test suite does cover most functions modified in this PR, like Participant.insert_into_communities().

[chadwhitacre]

The trigger function in this PR is used and checked in branch.sql itself.

That's good and useful now, but that doesn't protect us against regressions in the future. Can we move the nmembers check out of branch.sql (or duplicate it) into our test suite?

[Changaco]

Yes, we could. The DB self checks are a larger issue (related to #1549), in this PR I just tried to come up with a quick fix since the bug is visible in the UI.

[chadwhitacre]

@Changaco May I let you deploy?

[Changaco]

Yes, will do.

[chadwhitacre]

Thanks. :-)