Consider deprecating assert_select with a numeric arg

[chancancode]

Given a page like so:

<h1>Users</h1>

<table>
  ...
</table>

Total: <span class="total">4781</span>

It's pretty reasonable to write something like this:

get "/users"
assert_select "h1", "Users"
assert_select ".total", User.count

However, that would give you a very confusing error:

Failure:
MyApp::UsersTest#test_index:
Expected exactly 4781 elements matching ".total", found 1..
Expected: 4781
  Actual: 1

Given that we already support assert_select ".total", count: User.count, I think we should consider deprecating the numeric positional argument overload (as shown in the example) in favor of the explicit keyword argument, and potentially reclaiming the space for automatic to_s-ing the positional argument in the future (to make the example "just work").

[rafaelfranca]

👍

[chancancode]

@rafaelfranca can we still add the deprecation to 5.1?

[rafaelfranca]

Yes, we can. Even more that this would be a deprecation in a gem, so the deprecation would also happen in 5.0. I'm fine with it.

[chancancode]

@rafaelfranca we can (probably should) bump the gem version, then we can decide whether we need to lock it in Rails 5.0

[rafaelfranca]

yes, a minor version should be sufficient

[kaspth]

Yes please!