test: decouple request parameter validation

Author: razor-x

codegen/layouts/partials/client-method.hbs

@@ -10,9 +10,11 @@
 {{/if}}
       def {{name}}{{#if hasSignature}}({{signatureParams}}){{/if}}
 {{#if requiresAtLeastOneParameter}}
-        if {{#each atLeastOneParameterNames}}{{this}}.nil?{{#unless @last}} && {{/unless}}{{/each}}
-          raise TypeError, "At least one parameter is required for {{path}}"
-        end
+        Seam::RequestParameters.require_at_least_one(
+          "{{path}}",
+          {{bodyParams}},
+          [{{#each atLeastOneParameterNames}}:{{this}}{{#unless @last}}, {{/unless}}{{/each}}]
+        )
 
 {{/if}}        {{#if usesRes}}res = {{/if}}@client.{{httpMethod}}("{{path}}"{{#if hasParams}}, {{bodyParams}}.compact{{/if}})
 {{#if isResource}}

lib/seam.rb

@@ -2,6 +2,7 @@
 
 require_relative "seam/errors"
 require_relative "seam/null"
+require_relative "seam/request_parameters"
 require_relative "seam/url_search_params"
 require_relative "seam/strict_url_search_params_serializer"
 require_relative "seam/http"

lib/seam/request_parameters.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+module Seam
+  module RequestParameters
+    def self.require_at_least_one(path, parameters, parameter_names)
+      return if parameter_names.any? { |name| !parameters[name].nil? }
+
+      raise TypeError, "At least one parameter is required for #{path}"
+    end
+  end
+end