FI-2015 GET requests added to fhir_operation

lib/inferno/dsl/fhir_client.rb

@@ -60,26 +60,59 @@
         @fhir_clients ||= {}
       end
 
+      # Move parameters from body to the path for GET operations
+      #
+      # @param path [String]
+      # @param body [FHIR::Parameters] Must all be primitive if making GET request
+      # @private
+      def body_to_path(body)
+        query_hash = body.parameter.reduce({}) do |query, param|
+          valid = param.valid? && param.part.empty? && param.resource.nil? # Parameter is valid
+          param_val = param.to_hash.except('name') # should contain only one value if is a valid parameter
+          if valid && !param_val.empty? && FHIR.primitive?(datatype: param_val.keys[0][5..], value: param_val.values[0])
+            query.merge!({ param.name => param_val.values[0] })
+            query
+          else
+            # Handle the case of nonprimitive
+            Inferno::Application[:logger].error "Cannot use GET request with non-primitive datatype #{param.name}"
+            raise ArgumentError, "Cannot use GET request with non-primitive datatype #{param.name}"
+          end
+        end
+        query_hash.to_query
+      end
+
       # Perform a FHIR operation
       #
       # @note This is a placeholder method until the FHIR::Client supports
-      #   general operations
+      #   general operations.  Note that while both POST and GET methods are allowed,
+      #   GET is only allowed when the operation does not affect the servers state.
+      #   See https://build.fhir.org/operationdefinition-definitions.html#OperationDefinition.affectsState
       #
       # @param path [String]
-      # @param body [FHIR::Parameters]
+      # @param body [FHIR::Parameters] Must all be primitive if making GET request
       # @param client [Symbol]
       # @param name [Symbol] Name for this request to allow it to be used by
       #   other tests
       # @param headers [Hash] custom headers for this operation
+      # @param search_method [Symbol] indicates which request type to use for the operation
       # @return [Inferno::Entities::Request]
-      def fhir_operation(path, body: nil, client: :default, name: nil, headers: {})
+      def fhir_operation(path, body: nil, client: :default, name: nil, headers: {}, operation_method: :post)
         store_request_and_refresh_token(fhir_client(client), name) do
           tcp_exception_handler do
             operation_headers = fhir_client(client).fhir_headers
             operation_headers.merge!('Content-Type' => 'application/fhir+json') if body.present?
             operation_headers.merge!(headers) if headers.present?
-
-            fhir_client(client).send(:post, path, body, operation_headers)
+            case operation_method
+            when :post
+              fhir_client(client).send(:post, path, body, operation_headers)
+            when :get
+              path = "#{path}?#{body_to_path(body)}" if body.present?
+              fhir_client(client).send(:get, path, operation_headers)
+            else
+              # Handle the case of non-supported operation_method
+              Inferno::Application[:logger].error "Cannot perform #{operation_method} requests, use GET or POST"
+              raise ArgumentError, "Cannot perform #{operation_method} requests, use GET or POST"
+            end
           end
         end
       end