Deprecate force association reload by passing true

This is to simplify the association API, as you can call `reload` on the
association proxy or the parent object to get the same result.

For collection association, you can call `#reload` on association proxy
to force a reload:

    @user.posts.reload   # Instead of @user.posts(true)

For singular association, you can call `#reload` on the parent object to
clear its association cache then call the association method:

    @user.reload.profile   # Instead of @user.profile(true)

Passing a truthy argument to force association to reload will be removed
in Rails 5.1.

2 files changed, 16 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/associations/collection_association.rb b/activerecord/lib/active_record/associations/collection_association.rb
index 6caadb4ce8..87576abd92 100644
--- a/activerecord/lib/active_record/associations/collection_association.rb
+++ b/activerecord/lib/active_record/associations/collection_association.rb
@@ -1,3 +1,5 @@
+require "active_support/deprecation"
+
 module ActiveRecord
   module Associations
     # = Active Record Association Collection
@@ -28,6 +30,12 @@ module ActiveRecord
       # Implements the reader method, e.g. foo.items for Foo.has_many :items
       def reader(force_reload = false)
         if force_reload
+          ActiveSupport::Deprecation.warn(<<-MSG.squish)
+            Passing an argument to force an association to reload is now
+            deprecated and will be removed in Rails 5.1. Please call `reload`
+            on the result collection proxy instead.
+          MSG
+
           klass.uncached { reload }
         elsif stale_target?
           reload
diff --git a/activerecord/lib/active_record/associations/singular_association.rb b/activerecord/lib/active_record/associations/singular_association.rb
index bec9505bd2..30c5d72482 100644
--- a/activerecord/lib/active_record/associations/singular_association.rb
+++ b/activerecord/lib/active_record/associations/singular_association.rb
@@ -1,9 +1,17 @@
+require "active_support/deprecation"
+
 module ActiveRecord
   module Associations
     class SingularAssociation < Association #:nodoc:
       # Implements the reader method, e.g. foo.bar for Foo.has_one :bar
       def reader(force_reload = false)
         if force_reload && klass
+          ActiveSupport::Deprecation.warn(<<-MSG.squish)
+            Passing an argument to force an association to reload is now
+            deprecated and will be removed in Rails 5.1. Please call `reload`
+            on the parent object instead.
+          MSG
+
           klass.uncached { reload }
         elsif !loaded? || stale_target?
           reload