test for UTF8 job failure sanitization

thanks to @myronmarston

test/resque_failure_redis_test.rb

@@ -0,0 +1,23 @@
+require 'test_helper'
+require 'resque/failure/redis'
+
+context "Resque::Failure::Redis" do
+  setup do
+    @bad_string    = [39, 250, 141, 168, 138, 191, 52, 211, 159, 86, 93, 95, 39].map { |c| c.chr }.join
+    exception      = StandardError.exception(@bad_string)
+    worker         = Resque::Worker.new(:test)
+    queue          = "queue"
+    payload        = { "class" => Object, "args" => 3 }
+    @redis_backend = Resque::Failure::Redis.new(exception, worker, queue, payload)
+  end
+
+  test 'cleans up bad strings before saving the failure, in order to prevent errors on the resque UI' do
+    # test assumption: the bad string should not be able to round trip though JSON
+    assert_raises(MultiJson::DecodeError) {
+      MultiJson.decode(MultiJson.encode(@bad_string))
+    }
+
+    @redis_backend.save
+    Resque::Failure::Redis.all # should not raise an error
+  end
+end