revises 877e42e2

* A string in the example lacked quotes.

* The tests asserted stuff about :last_name, whereas
  test params do not have that key.

* But, the first one passed, why? After hitting my head against
  the wall and doing some obscure rituals realized the new
  #require had an important typo, wanted to iterate over the
  array argument (key), but it ran over its own hash keys
  (method #keys).

* Modified the test to prevent the same typo to happen again.

* The second test assigned to an unused variable safe_params
  that has been therefore removed.

* Grammar of the second test description.

* Since I was on it, reworded both test descriptions.

actionpack/lib/action_controller/metal/strong_parameters.rb

@@ -256,11 +256,11 @@ def permit!
     #   ActionController::Parameters.new(first_name: 'Gaurish', title: nil).require([:first_name, :title])
     #   # => ActionController::ParameterMissing: param is missing or the value is empty: title
     #
-    #   params = ActionController::Parameters.new(first_name: 'Gaurish', title: Mjallo)
+    #   params = ActionController::Parameters.new(first_name: 'Gaurish', title: 'Mjallo')
     #   first_name, title = params.require([:first_name, :title])
     #
     def require(key)
-      return keys.map { |k| require(k) } if key.is_a?(Array)
+      return key.map { |k| require(k) } if key.is_a?(Array)
       value = self[key]
       if value.present? || value == false
         value

actionpack/test/controller/required_params_test.rb

@@ -49,20 +49,20 @@ class ParametersRequireTest < ActiveSupport::TestCase
     end
   end
 
-  test "require array of params" do
-    safe_params = ActionController::Parameters.new(person: {first_name: 'Gaurish', title: 'Mjallo'})
+  test "require array when all required params are present" do
+    safe_params = ActionController::Parameters.new(person: {first_name: 'Gaurish', title: 'Mjallo', city: 'Barcelona'})
       .require(:person)
-      .require([:first_name, :last_name])
+      .require([:first_name, :title])
 
     assert_kind_of Array, safe_params
     assert_equal ['Gaurish', 'Mjallo'], safe_params
   end
 
-  test "require array when it contains a nil values" do
+  test "require array when a required param is missing" do
     assert_raises(ActionController::ParameterMissing) do
-      safe_params = ActionController::Parameters.new(person: {first_name: 'Gaurish', title: nil})
+      ActionController::Parameters.new(person: {first_name: 'Gaurish', title: nil})
         .require(:person)
-        .require([:first_name, :last_name])
+        .require([:first_name, :title])
     end
   end
 end