v5.19's removal of MiniTest compatiblity layer broke Mocha

[kyrofa]

See freerange/mocha#614 . I appreciate the MT_COMPAT environment variable, but that's still an API break, and it broke a number of our projects before we found what was happening. Any reason this wasn't done in a major version bump? Or does minitest not use semantic versioning?

[zenspider]

[matejzero]

I'm seeing the same with puppet's beaker tests:

An error occurred while loading ./spec/acceptance/class_spec.rb.
Failure/Error: require 'beaker'
NameError:
  uninitialized constant MiniTest
  Did you mean?  Minitest
...

[pgundlupetvenkatesh]

I got this with Minitest Spec

<path>/Ruby32-x64/lib/ruby/gems/3.2.0/gems/minitest-hooks-1.5.0/lib/minitest/hooks/default.rb:3:in `<top (required)>': uninitialized constant MiniTest (NameError)

MiniTest::Spec.register_spec_type(//, Minitest::HooksSpec)
        ^^^^^^
Did you mean?  Minitest
        from <internal:<path>/Ruby32-x64/lib/ruby/site_ruby/3.2.0/rubygems/core_ext/kernel_require.rb>:37:in `require'
        from <internal:<path>/Ruby32-x64/lib/ruby/site_ruby/3.2.0/rubygems/core_ext/kernel_require.rb>:37:in `require'

Workaround - Downgrading Minitest to v5.18.1 works for now.

[kyrofa]

@zenspider that's a little disingenuous. Yes, Minitest has been around for a long time, but MiniTest has been stable and never caused deprecation warnings, so old gems of course are still using it-- what would cause them to update?

To be clear, I have zero issue with this API change. My problem is that it was shipped without a major version bump, which breaks applications with even pessimistic dependency versions (e.g. gem 'minitest', '~> 5.16'). Semantic versioning is a contract between maintainers and users; a way to give maintainers the freedom to make changes like this as they see fit while communicating them to users and giving them a chance to opt in to those updates (and update their code) as needed and on their schedule.

Which makes me ask again: does minitest use semantic versioning? Or should we be locking our minitest dependency versions down?

[zenspider]

"Disingenuous" is titling this issue "removal of MiniTest compatiblity layer".

Mocha has known about the name change for over a decade and yet persists (even after doing a "fix" today) on using the old namespace.

Real fix:

1. Don't use MiniTest.

Legitimate workarounds:

1. export MT_COMPAT=1
2. `require "minitest/unit" in your test_helper / whereever.
3. and I suppose pinning back to 5.18.1 if you have some esoteric reason why you can't do any of the others.