FI-2035: refactor resource_is_valid? and check for non-json responses

lib/inferno/dsl/fhir_validation.rb

@@ -116,27 +116,14 @@ def exclude_message(&block)
         def resource_is_valid?(resource, profile_url, runnable)
           profile_url ||= FHIR::Definitions.resource_definition(resource.resourceType).url
 
-          begin
-            validation_response = validate(resource, profile_url)
-          rescue StandardError => e
-            runnable.add_message('error', e.message)
-            raise Inferno::Exceptions::ErrorInValidatorException, "Unable to connect to validator at #{url}."
-          end
+          outcome, http_status = validate(resource, profile_url, runnable)
 
-          # The validator should return OperationOutcome both on successful validation and on error,
-          # so parse the OO before checking the HTTP status code.
-          outcome = FHIR::OperationOutcome.new(JSON.parse(validation_response.body))
-
-          message_hashes = outcome.issue&.map { |issue| message_hash_from_issue(issue, resource) } || []
-
-          message_hashes.concat(additional_validation_messages(resource, profile_url))
-
-          filter_messages(message_hashes)
+          message_hashes = message_hashes_from_outcome(outcome, resource, profile_url)
 
           message_hashes
             .each { |message_hash| runnable.add_message(message_hash[:type], message_hash[:message]) }
 
-          unless validation_response.status == 200
+          unless http_status == 200
             raise Inferno::Exceptions::ErrorInValidatorException,
                   'Error occurred in the validator. Review Messages tab or validator service logs for more information.'
           end
@@ -156,6 +143,17 @@ def filter_messages(message_hashes)
           message_hashes.reject! { |message| exclude_message.call(Entities::Message.new(message)) } if exclude_message
         end
 
+        # @private
+        def message_hashes_from_outcome(outcome, resource, profile_url)
+          message_hashes = outcome.issue&.map { |issue| message_hash_from_issue(issue, resource) } || []
+
+          message_hashes.concat(additional_validation_messages(resource, profile_url))
+
+          filter_messages(message_hashes)
+
+          message_hashes
+        end
+
         # @private
         def message_hash_from_issue(issue, resource)
           {
@@ -193,12 +191,32 @@ def issue_message(issue, resource)
         #
         # @param resource [FHIR::Model]
         # @param profile_url [String]
-        # @return [Faraday::Response] the validation response
-        def validate(resource, profile_url)
-          Faraday.new(
-            url,
-            params: { profile: profile_url }
-          ).post('validate', resource.source_contents)
+        # @return [[Array(FHIR::OperationOutcome, Number)] the validation response and HTTP status code
+        def validate(resource, profile_url, runnable)
+          begin
+            response = Faraday.new(
+              url,
+              params: { profile: profile_url }
+            ).post('validate', resource.source_contents)
+          rescue StandardError => e
+            runnable.add_message('error', e.message)
+            raise Inferno::Exceptions::ErrorInValidatorException, "Unable to connect to validator at #{url}."
+          end
+          outcome = operation_outcome_from_validator_response(response.body, runnable)
+
+          [outcome, response.status]
+        end
+
+        # @private
+        def operation_outcome_from_validator_response(response, runnable)
+          if response.start_with? '{'
+            FHIR::OperationOutcome.new(JSON.parse(response))
+          else
+            runnable.add_message('error', "Validator Response: #{response}")
+            raise Inferno::Exceptions::ErrorInValidatorException,
+                  'Validator response was an unexpected format. '\
+                  'Review Messages tab or validator service logs for more information.'
+          end
         end
       end