spec: gracefully handle sharding not initializing in specs

also bumps switchman for similar error handling

refs CNVS-21900

Change-Id: I5c4f8d91bc5b6d3d0e6dc01ef3388fcc4d9b6c36
Reviewed-on: https://gerrit.instructure.com/65924
Tested-by: Jenkins
Reviewed-by: Jon Jensen <jon@instructure.com>
Product-Review: Jon Jensen <jon@instructure.com>
QA-Review: Jon Jensen <jon@instructure.com>

Author: ccutrer

Gemfile.d/app.rb

@@ -19,7 +19,7 @@
 gem 'active_model-better_errors', '1.6.7', require: 'active_model/better_errors'
 gem 'dynamic_form', '1.1.4', require: false
 gem 'rails-patch-json-encode', '0.0.1'
-gem 'switchman', '1.3.8'
+gem 'switchman', '1.3.9'
 gem 'folio-pagination', '0.0.9', require: 'folio/rails'
   # for folio, see the folio README
   gem 'will_paginate', '3.0.7', require: false

spec/support/onceler/sharding.rb

@@ -2,6 +2,7 @@ module Onceler
   module Sharding
     def self.included(klass)
       klass.onceler_connections = ->(_) do
+        next [] if Switchman::RSpecHelper.class_variable_get(:@@sharding_failed)
         shard1 = Switchman::RSpecHelper.class_variable_get(:@@shard1)
         shard2 = Switchman::RSpecHelper.class_variable_get(:@@shard2)
         # mirror logic of https://github.com/instructure/switchman/blob/61f2e9d/lib/switchman/r_spec_helper.rb#L94
@@ -12,6 +13,8 @@ def self.included(klass)
       end
 
       klass.before :record do
+        sharding_failed = Switchman::RSpecHelper.class_variable_get(:@@sharding_failed)
+        raise "Sharding did not set up correctly" if sharding_failed
         @shard1 = Shard.find(Switchman::RSpecHelper.class_variable_get(:@@shard1))
         @shard2 = Shard.find(Switchman::RSpecHelper.class_variable_get(:@@shard2))
       end