The Concurrent::Map default_proc is passed a Concurrent::Hash instead of the Concurrent::Map

[mensfeld]

With concurrent-ruby 1.2.0 things work as expected. With 1.2.1 I get following error:

undefined method `compute_if_absent' for {}:Concurrent::Hash (NoMethodError)

relevant stacktrace:

gems/concurrent-ruby-1.2.1/lib/concurrent-ruby/concurrent/collection/map/non_concurrent_map_backend.rb:22:in `[]'

it's a divination of behaviour of map, working on repro 🙏

# Works in 1.2.0 but breaks in 1.2.1
@listeners = Concurrent::Map.new do |h, k|
  h.compute_if_absent(k) { Concurrent::Array.new }
end

@listeners[:a]

[dentarg]

A regression from #989? Yeah: https://github.com/ruby-concurrency/concurrent-ruby/pull/989/files#diff-205e0f04e361a0beb29983f5bfba8710659e00eed759c0f556881fa23ac8540d

[9mm]

Yikes this will teach me to update minor libs before deploying

[eregon]

Sorry about this bug, I'll make a release with the fix ASAP.

[misdoro]

Same for fetch_or_store method on the Hash:

NoMethodError: undefined method `fetch_or_store' for {}:Concurrent::Hash
          h.fetch_or_store(key, Concurrent::Map.new)

[eregon]

Fixed in f2985bd
Released as https://github.com/ruby-concurrency/concurrent-ruby/releases/tag/v1.2.2

[mensfeld]

Thank you for such fast turnaround!

[nijikon]

That was super quick, thanks!

[jcoyne]

Thank you for the fix. ❤️