AMo #key is now #to_key and CI is probably happy

Obviously #key is a too common name to be included
in the AMo interface, #to_key fits better and also
relates nicely to #to_param. Thx wycats, koz and
josevalim for the suggestion.

AR's #to_key implementation now takes customized
primary keys into account and there's a testcase
for that too.

The #to_param AMo lint makes no assumptions on how
the method behaves in the presence of composite
primary keys. It leaves the decision wether to
provide a default, or to raise and thus signal to
the user that implementing this method will need
his special attention, up to the implementers. All
AMo cares about is that #to_param is implemented
and returns nil in case of a new_record?.

The default CompliantObject used in lint_test
provides a naive default implementation that just
joins all key attributes with '-'.

The #to_key default implementation in lint_test's
CompliantObject now returns [id] instead of [1].
This was previously causing the (wrong) tests I
added for AR's #to_key implementation to pass. The
#to_key tests added with this patch should be
better.

The CI failure was caused by my lack of knowledge
about the test:isolated task. The tests for the
record_identifier code in action_controller are
using fake non AR models and I forgot to stub the
#to_key method over there. This issue didn't come
up when running the test task, only test:isolated
revealed it. This patch fixes that.

All tests pass isolated or not, well, apart from
one previously unpended test in action_controller
that is unrelated to my patch.

3 files changed, 11 insertions, 10 deletions

diff --git a/actionpack/test/controller/record_identifier_test.rb b/actionpack/test/controller/record_identifier_test.rb
index 6b6d154faa..813dedc80d 100644
--- a/actionpack/test/controller/record_identifier_test.rb
+++ b/actionpack/test/controller/record_identifier_test.rb
@@ -5,6 +5,7 @@ class Comment
   include ActiveModel::Conversion
 
   attr_reader :id
+  def to_key; id ? [id] : nil end
   def save; @id = 1 end
   def new_record?; @id.nil? end
   def name
diff --git a/actionpack/test/lib/controller/fake_models.rb b/actionpack/test/lib/controller/fake_models.rb
index e4aed14dc0..4475d40f63 100644
--- a/actionpack/test/lib/controller/fake_models.rb
+++ b/actionpack/test/lib/controller/fake_models.rb
@@ -6,7 +6,7 @@ class Customer < Struct.new(:name, :id)
 
   undef_method :to_json
 
-  def key
+  def to_key
     id ? [id] : nil
   end
 
@@ -47,7 +47,7 @@ module Quiz
     extend ActiveModel::Naming
     include ActiveModel::Conversion
 
-    def key
+    def to_key
       id ? [id] : nil
     end
 
@@ -67,7 +67,7 @@ class Post < Struct.new(:title, :author_name, :body, :secret, :written_on, :cost
 
   alias_method :secret?, :secret
 
-  def key
+  def to_key
     id ? [id] : nil
   end
 
@@ -96,7 +96,7 @@ class Comment
   attr_reader :id
   attr_reader :post_id
   def initialize(id = nil, post_id = nil); @id, @post_id = id, post_id end
-  def key; id ? [id] : nil end
+  def to_key; id ? [id] : nil end
   def save; @id = 1; @post_id = 1 end
   def new_record?; @id.nil? end
   def to_param; @id; end
@@ -116,7 +116,7 @@ class Tag
   attr_reader :id
   attr_reader :post_id
   def initialize(id = nil, post_id = nil); @id, @post_id = id, post_id end
-  def key; id ? [id] : nil end
+  def to_key; id ? [id] : nil end
   def save; @id = 1; @post_id = 1 end
   def new_record?; @id.nil? end
   def to_param; @id; end
@@ -136,7 +136,7 @@ class CommentRelevance
   attr_reader :id
   attr_reader :comment_id
   def initialize(id = nil, comment_id = nil); @id, @comment_id = id, comment_id end
-  def key; id ? [id] : nil end
+  def to_key; id ? [id] : nil end
   def save; @id = 1; @comment_id = 1 end
   def new_record?; @id.nil? end
   def to_param; @id; end
@@ -152,7 +152,7 @@ class TagRelevance
   attr_reader :id
   attr_reader :tag_id
   def initialize(id = nil, tag_id = nil); @id, @tag_id = id, tag_id end
-  def key; id ? [id] : nil end
+  def to_key; id ? [id] : nil end
   def save; @id = 1; @tag_id = 1 end
   def new_record?; @id.nil? end
   def to_param; @id; end
diff --git a/actionpack/test/template/prototype_helper_test.rb b/actionpack/test/template/prototype_helper_test.rb
index dab34f1201..45f9d85e32 100644
--- a/actionpack/test/template/prototype_helper_test.rb
+++ b/actionpack/test/template/prototype_helper_test.rb
@@ -4,7 +4,7 @@ require 'active_model'
 class Bunny < Struct.new(:Bunny, :id)
   extend ActiveModel::Naming
   include ActiveModel::Conversion
-  def key() id ? [id] : nil end
+  def to_key() id ? [id] : nil end
 end
 
 class Author
@@ -12,7 +12,7 @@ class Author
   include ActiveModel::Conversion
 
   attr_reader :id
-  def key() id ? [id] : nil end
+  def to_key() id ? [id] : nil end
   def save; @id = 1 end
   def new_record?; @id.nil? end
   def name
@@ -25,7 +25,7 @@ class Article
   include ActiveModel::Conversion
   attr_reader :id
   attr_reader :author_id
-  def key() id ? [id] : nil end
+  def to_key() id ? [id] : nil end
   def save; @id = 1; @author_id = 1 end
   def new_record?; @id.nil? end
   def name