Cleanups for Data#deconstruct_keys and Struct#deconstruct_keys

* Use the correct method name in the description for
  Data#deconstruct_keys
* Add blank line between Data object creation and specs, to keep this
  consistent.
* Add spec for incorrect index for Struct#deconstruct_keys, this spec
  was present for Data#deconstruct_keys, but missing for Struct.

Author: herwinw

core/data/deconstruct_keys_spec.rb

@@ -1,10 +1,11 @@
 require_relative '../../spec_helper'
 require_relative 'fixtures/classes'
 
-describe "Data#deconstruct" do
+describe "Data#deconstruct_keys" do
   it "returns a hash of attributes" do
     klass = Data.define(:x, :y)
     d = klass.new(1, 2)
+
     d.deconstruct_keys([:x, :y]).should == {x: 1, y: 2}
   end
 
@@ -29,6 +30,7 @@
   it "accepts string attribute names" do
     klass = Data.define(:x, :y)
     d = klass.new(1, 2)
+
     d.deconstruct_keys(['x', 'y']).should == {'x' => 1, 'y' => 2}
   end
 
@@ -58,6 +60,7 @@
   it "returns an empty hash when there are more keys than attributes" do
     klass = Data.define(:x, :y)
     d = klass.new(1, 2)
+
     d.deconstruct_keys([:x, :y, :x]).should == {}
   end
 

core/struct/deconstruct_keys_spec.rb

@@ -43,6 +43,13 @@
     s.deconstruct_keys([-1]     ).should == {-1 => 30}
   end
 
+  it "ignores incorrect position numbers" do
+    struct = Struct.new(:x, :y, :z)
+    s = struct.new(10, 20, 30)
+
+    s.deconstruct_keys([0, 3]).should == {0 => 10}
+  end
+
   it "support mixing attribute names and argument position numbers" do
     struct = Struct.new(:x, :y)
     s = struct.new(1, 2)