Treat ActiveRecord::ConnectionFailed as transient

lib/solid_cache/store/failsafe.rb

@@ -5,6 +5,7 @@ class Store
     module Failsafe
       TRANSIENT_ACTIVE_RECORD_ERRORS = [
         ActiveRecord::AdapterTimeout,
+        ActiveRecord::ConnectionFailed,
         ActiveRecord::ConnectionNotEstablished,
         ActiveRecord::Deadlocked,
         ActiveRecord::LockWaitTimeout,

test/test_helper.rb

@@ -95,10 +95,10 @@ def shard_keys(cache, shard)
     shard_keys.map { |key| key.delete_prefix("#{@namespace}:") }
   end
 
-  def emulating_timeouts
+  def emulating_timeouts(error = ActiveRecord::StatementTimeout)
     ar_methods = [ :select_all, :delete, :exec_insert_all ]
     stub_matcher = ActiveRecord::Base.connection.class.any_instance
-    ar_methods.each { |method| stub_matcher.stubs(method).raises(ActiveRecord::StatementTimeout) }
+    ar_methods.each { |method| stub_matcher.stubs(method).raises(error) }
     yield
   ensure
     ar_methods.each { |method| stub_matcher.unstub(method) }

test/unit/solid_cache_test.rb

@@ -89,6 +89,27 @@ def emulating_unavailability
   end
 end
 
+class SolidCacheFailsafeConnectionFailedTest < ActiveSupport::TestCase
+  include FailureSafetyBehavior
+
+  setup do
+    @cache = nil
+    @namespace = "test-#{SecureRandom.hex}"
+
+    @cache = lookup_store(expires_in: 60)
+
+    # For LocalCacheBehavior tests
+    @peek = lookup_store(expires_in: 60)
+  end
+
+  def emulating_unavailability
+    wait_for_background_tasks(@cache)
+    emulating_timeouts(ActiveRecord::ConnectionFailed) do
+      yield lookup_store(namespace: @namespace)
+    end
+  end
+end
+
 class SolidCacheRaisingTest < ActiveSupport::TestCase
   include FailureRaisingBehavior