Improve Rails 7.2 compatibility

[jamiecobbett]

On trying to upgrade to Rails 7.2, I was experiencing

[SystemStackError: stack level too deep (SystemStackError)]

On debugging, I found the object triggering this was an instance of ActiveRecord::Transaction:

=> #<ActiveRecord::Transaction:0x00000001211be2a8
 @internal_transaction=
  #<ActiveRecord::ConnectionAdapters::RealTransaction:0x0000000121b1a298
   @callbacks=nil,
   @connection=#<ActiveRecord::ConnectionAdapters::PostgreSQLAdapter:0x0000000000ec40 env_name="development" role=:writing>,
   @dirty=false,
   @instrumenter=
    #<ActiveRecord::ConnectionAdapters::TransactionInstrumenter:0x00000001211be258
     @base_payload=
      {:connection=>#<ActiveRecord::ConnectionAdapters::PostgreSQLAdapter:0x0000000000ec40 env_name="development" role=:writing>,
       :transaction=>#<ActiveRecord::Transaction:0x00000001211be2a8 ...>},
     @handle=nil,
     @payload=nil,
     @started=false>,
   @isolation_level=nil,
   @joinable=true,
   @lazy_enrollment_records=nil,
   @materialized=false,
   @records=
    [#<User REDACTED>],
   @run_commit_callbacks=true,
   @state=#<ActiveRecord::ConnectionAdapters::TransactionState:0x00000001211be348 @children=nil, @state=nil>,
   @user_transaction=#<ActiveRecord::Transaction:0x00000001211be2a8 ...>,
   @written=true>,
 @uuid=nil>

Adding this condition in appears to fix the problem.

I think this fixes #206

This kind of problem seems to be a perennial issue in the gem. I know that super_diff has similar issues - they have a "RecursionGuard", maybe that pattern could be applied to meta_request too?

[jamiecobbett]

@dejan let me know if there's anything I can do to make merging this easier - we are so grateful that this gem and extension exist ❤️

[mahmoudimus]

@dejan and @jamiecobbett this fix works for us. I'm grateful for your contribution and this gem. We will need to relax the railties restriction as well if we want this to work for rails 8.0.

[dejan]

@jamiecobbett thanks for the contribution!

[jamiecobbett]

@dejan no problem 👍

I thought I'd have a go at rails 8, and I opened a PR here cc @mahmoudimus