Fix bug in FiberedMysql2Adapter_5_2 where steal! needed to update its owner to Fiber.current

CHANGELOG.md

@@ -4,11 +4,16 @@ Inspired by [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 Note: this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.1.1] - UNRELEASED
+### Fixed
+- Fixed bug with Rails 5+ adapter where connections that have `steal!` called on them were not having their owner updated to the current Fiber, which would then cause an exception when trying to expire the connection (this showed up with the Rails 5 `ConnectionPool::Reaper` that reaps unused connections)
+
 ## [0.1.0] - 2020-10-23
 ### Added
 - Added an adapter for Rails 4, 5, and 6.
 - Added appraisals for Rails 4, 5, and 6.
 - Added TravisCI unit test pipeline.
 - Added coverage reports via Coveralls.
 
+[0.1.1]: https://github.com/Invoca/fibered_mysql2/compare/v0.1.0..v0.1.1
 [0.1.0]: https://github.com/Invoca/fibered_mysql2/tree/v0.1.0

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    fibered_mysql2 (0.1.0)
+    fibered_mysql2 (0.1.1)
       em-synchrony (~> 1.0)
       rails (>= 4.2, < 7)
 

lib/active_record/connection_adapters/fibered_mysql2_adapter.rb

@@ -49,6 +49,18 @@ def expire
         raise ::ActiveRecord::ActiveRecordError, "Cannot expire connection, it is not currently leased."
       end
     end
+
+    def steal!
+      if in_use?
+        if @owner != Fiber.current
+          pool.send :remove_connection_from_thread_cache, self, @owner
+
+          @owner = Fiber.current
+        end
+      else
+        raise ::ActiveRecord::ActiveRecordError, "Cannot steal connection, it is not currently leased."
+      end
+    end
   end
 
   class FiberedMysql2Adapter < ::ActiveRecord::ConnectionAdapters::EMMysql2Adapter

lib/fibered_mysql2/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module FiberedMysql2
-  VERSION = "0.1.0"
+  VERSION = "0.1.1"
 end

spec/unit/fibered_mysql2_adapter_spec.rb

@@ -67,5 +67,38 @@
         end
       end
     end
+
+    context '#steal!' do
+      subject { adapter.steal! }
+
+      context 'if the connection is not in use' do
+        it 'raises' do
+          expect { subject }.to raise_exception(ActiveRecord::ActiveRecordError, "Cannot steal connection, it is not currently leased.")
+        end
+      end
+
+      context 'if the connection is being used' do
+        before do
+          ActiveRecord::Base.establish_connection(
+            adapter: 'fibered_mysql2',
+            database: 'widgets',
+            username: 'root',
+            pool: 10
+          )
+
+          adapter.pool = ActiveRecord::Base.connection_pool
+          adapter.lease
+        end
+
+        it { should be_nil }
+
+        it 'by a different Fiber' do
+          new_fiber = Fiber.new { subject }
+          new_fiber.resume
+
+          expect(adapter.owner).to eq(new_fiber)
+        end
+      end
+    end
   end
 end