Warn on missing :on in joins

[sabiwara]

Add a warning when :on is missing and defaults to true, as proposed here:

I think emitting a warning if the on option is missing and there is no assoc is a good compromise.

[sabiwara]

I struggled a bit to come up with a useful warning with the proper line number, else it would be quite un-helpful:

With IO.warn (stacktrace isn't helpful):

[greg-rychlewski]

I think documenting that it defaults to on: true would also be helpful.

Also not sure I understand why on: true had to be added to all those tests.

[sabiwara]

I think documenting that it defaults to on: true would also be helpful.

Got it, will add it 👍

Also not sure I understand why on: true had to be added to all those tests.

This was to avoid having a wall of warnings when running tests, but I can revert test files if you prefer?
I should have asked before fixing all of them, this was most of the work to be honest 😂

[greg-rychlewski]

This was to avoid having a wall of warnings when running tests, but I can revert test files if you prefer?

Ah I thought the tests were run on :error level. Sorry about that.

[greg-rychlewski]

Thank you!