See test cases in spec/schema_spec.rb.
Run:
bundle
bin/rails spec
Output excerpt:
.F
Failures:
1) GraphqlValidationComplexitySchema errors with connection type
Failure/Error: result = described_class.execute(query_string, max_complexity: 100)
NoMethodError:
undefined method `[]' for #<GraphQL::Schema::Validator::ValidationFailedError:0x000000011d389c80>