v5.0.0: Complain about unknown hash values

README.md

@@ -58,6 +58,8 @@ Also provides conveniences for creating value objects, method objects, query met
 
 `attr_initialize [:bar, :baz!]` defines an initializer that takes one hash argument, assigning `@bar` (optional) and `@baz` (required).
 
+If you pass unknown hash arguments, you will get an `ArgumentError`.
+
 `attr_initialize` can also accept a block which will be invoked after initialization. This is useful for e.g. initializing private data as necessary.
 
 

lib/attr_extras/attr_initialize.rb

@@ -21,6 +21,12 @@ def apply
         if name_or_names.is_a?(Array)
           hash = value || {}
 
+          known_keys = name_or_names.map { |name| name.to_s.sub(/!\z/, "").to_sym }
+          unknown_keys = hash.keys - known_keys
+          if unknown_keys.any?
+            raise ArgumentError, "Got unknown keys: #{unknown_keys.inspect}; allowed keys: #{known_keys.inspect}"
+          end
+
           name_or_names.each do |name|
             set_ivar_from_hash.call(self, name, hash)
           end

lib/attr_extras/version.rb

@@ -1,3 +1,3 @@
 module AttrExtras
-  VERSION = "4.6.0"
+  VERSION = "5.0.0"
 end

spec/attr_extras/attr_initialize_spec.rb

@@ -56,6 +56,18 @@ def self.name
     lambda { klass.new(:optional => "X") }.must_raise KeyError
   end
 
+  it "complains about unknown hash values" do
+    klass = Class.new do
+      attr_initialize :foo, [:bar]
+    end
+
+    # Should not raise.
+    klass.new("Foo", :bar => "Bar")
+
+    exception = lambda { klass.new("Foo", :bar => "Bar", :baz => "Baz") }.must_raise ArgumentError
+    exception.message.must_include "baz"
+  end
+
   it "accepts a block for initialization" do
     klass = Class.new do
       attr_initialize :value do