Better error handling pattern

Sets up a module in the same fashion as the JsonapiCompliable gem

Author: happycollision

lib/jsonapi_spec_helpers.rb

@@ -3,7 +3,7 @@
 require 'jsonapi_spec_helpers/helpers'
 require 'jsonapi_spec_helpers/payload'
 require 'jsonapi_spec_helpers/payload_sanitizer'
-require 'jsonapi_spec_helpers/error'
+require 'jsonapi_spec_helpers/errors'
 
 module JsonapiSpecHelpers
   def self.included(klass)

lib/jsonapi_spec_helpers/error.rb

@@ -0,0 +1,16 @@
+module JsonapiSpecHelpers
+  module Errors
+    class Base < StandardError; end
+    class IncludedOutOfBounds < Base
+      def initialize(type, index, array)
+        @type = type; @index = index; @array = array
+      end
+
+      def message
+        "You attempted to get an item at index #{@index} of the type '#{@type}' " \
+        "from the included property of your JSON payload. But it contained "    \
+        "#{@array.length} '#{@type}'"
+      end
+    end
+  end
+end

lib/jsonapi_spec_helpers/errors.rb

@@ -41,8 +41,7 @@ def json_includes(type, *indices)
       indices.each do |index|
         single_included = included.at(index)
         if single_included.nil?
-          raise JsonapiSpecHelpersError,
-            included_out_of_bounds_error(type, index, included)
+          raise Errors::IncludedOutOfBounds.new(type, index, included)
         end
         includes << json_item(from: single_included)
       end
@@ -101,12 +100,4 @@ def jsonapi_payload(input)
       PayloadSanitizer.new(input).sanitize
     end
   end
-
-private
-
-  def included_out_of_bounds_error(type, index, array)
-    "You attempted to get an item at index #{index} of the type '#{type}' " \
-    "from the included property of your JSON payload. But it contained "    \
-    "#{array.length} '#{type}'"
-  end
 end

lib/jsonapi_spec_helpers/helpers.rb

@@ -175,7 +175,7 @@
       end
 
       it 'throws when asking for an index beyond the length of the includes' do
-        expect{ json_includes('comments', 99) }.to raise_error JsonapiSpecHelpersError
+        expect{ json_includes('comments', 99) }.to raise_error JsonapiSpecHelpers::Errors::IncludedOutOfBounds
       end
     end
   end