Merge pull request #191 from cllns/add-class-name-to-missing-attribut…

…e-error

[changelog]

version: unreleased
changed: "Missing attribute error now includes the name of the class (issue #170 via #191) (@phillipoertel + @cllns)"

lib/dry/struct.rb

@@ -145,7 +145,9 @@ def initialize(attributes)
     #   rom_n_roda[:title] #=> 'Web Development with ROM and Roda'
     #   rom_n_roda[:subtitle] #=> nil
     def [](name)
-      @attributes.fetch(name) { raise MissingAttributeError, name }
+      @attributes.fetch(name) do
+        raise MissingAttributeError.new(attribute: name, klass: self.class)
+      end
     end
 
     # Converts the {Dry::Struct} to a hash with keys representing

lib/dry/struct/errors.rb

@@ -16,8 +16,8 @@ def initialize(key)
 
     # Raised when a struct doesn't have an attribute
     class MissingAttributeError < ::KeyError
-      def initialize(key)
-        super("Missing attribute: #{key.inspect}")
+      def initialize(attribute:, klass:)
+        super("Missing attribute: #{attribute.inspect} on #{klass}")
       end
     end
 

spec/integration/struct_spec.rb

@@ -353,7 +353,7 @@ class Task < Dry::Struct
 
       expect { value[:name] }
         .to raise_error(Dry::Struct::MissingAttributeError)
-        .with_message("Missing attribute: :name")
+        .with_message("Missing attribute: :name on Test::Task")
     end
 
     describe "protected methods" do