Deferred Garbage Collection for speeding up unit and integration tests

DeferredGarbageCollection.rb

# Public: This class contains methods for deferred garbage collection which
# improves the time consumption of integration and unit tests.
class DeferredGarbageCollection
  # Public: The time threshold used by the deferred garbage collection. It's
  # either set as an environment variable or defaults to 5 seconds.
  GC_THRESHOLD = (ENV['DEFER_GC'] || 5.0).to_f

  # Public: The last time the GC has run.
  @@last_gc_run = Time.now

  # Public: Starts the deferred Garbage Collection.
  def self.start
    GC.disable if GC_THRESHOLD > 0
  end

  # Public: Checks if last run time exceeds the value of the time threshold and
  # enables Garbage Collection for a short cleanup. After that Garbage
  # Collection is deferred again.
  def self.reconsider
    if GC_THRESHOLD > 0 && Time.now - @@last_gc_run >= GC_THRESHOLD
      GC.enable
      GC.start
      GC.disable
      @@last_gc_run = Time.now
    end
  end
end

# PUT THIS IN YOUR SPEC HELPER

config.before(:all) do
  DeferredGarbageCollection.start
end

config.after(:all) do
  DeferredGarbageCollection.reconsider
end