removes usage of Object#in? from the code base (the method remains defined by Active Support)

Selecting which key extensions to include in active_support/rails
made apparent the systematic usage of Object#in? in the code base.
After some discussion in

    https://github.com/rails/rails/commit/5ea6b0df9a36d033f21b52049426257a4637028d

we decided to remove it and use plain Ruby, which seems enough
for this particular idiom.

In this commit the refactor has been made case by case. Sometimes
include? is the natural alternative, others a simple || is the
way you actually spell the condition in your head, others a case
statement seems more appropriate. I have chosen the one I liked
the most in each case.

5 files changed, 15 insertions, 13 deletions

diff --git a/activerecord/lib/active_record/associations/association.rb b/activerecord/lib/active_record/associations/association.rb
index 4db7038d2e..9f47e7e631 100644
--- a/activerecord/lib/active_record/associations/association.rb
+++ b/activerecord/lib/active_record/associations/association.rb
@@ -176,7 +176,7 @@ module ActiveRecord
         def creation_attributes
           attributes = {}
 
-          if reflection.macro.in?([:has_one, :has_many]) && !options[:through]
+          if (reflection.macro == :has_one || reflection.macro == :has_many) && !options[:through]
             attributes[reflection.foreign_key] = owner[reflection.active_record_primary_key]
 
             if reflection.options[:as]
diff --git a/activerecord/lib/active_record/associations/has_one_association.rb b/activerecord/lib/active_record/associations/has_one_association.rb
index c5aed6e26a..191c4e8e39 100644
--- a/activerecord/lib/active_record/associations/has_one_association.rb
+++ b/activerecord/lib/active_record/associations/has_one_association.rb
@@ -51,16 +51,19 @@ module ActiveRecord
         end
 
         def remove_target!(method)
-          if method.in?([:delete, :destroy])
-            target.send(method)
-          else
-            nullify_owner_attributes(target)
+          case method
+            when :delete
+              target.delete
+            when :destroy
+              target.destroy
+            else
+              nullify_owner_attributes(target)
 
-            if target.persisted? && owner.persisted? && !target.save
-              set_owner_attributes(target)
-              raise RecordNotSaved, "Failed to remove the existing associated #{reflection.name}. " +
-                                    "The record failed to save when after its foreign key was set to nil."
-            end
+              if target.persisted? && owner.persisted? && !target.save
+                set_owner_attributes(target)
+                raise RecordNotSaved, "Failed to remove the existing associated #{reflection.name}. " +
+                                      "The record failed to save when after its foreign key was set to nil."
+              end
           end
         end
 
diff --git a/activerecord/lib/active_record/inheritance.rb b/activerecord/lib/active_record/inheritance.rb
index 7d759c1048..04fff99a6e 100644
--- a/activerecord/lib/active_record/inheritance.rb
+++ b/activerecord/lib/active_record/inheritance.rb
@@ -55,7 +55,7 @@ module ActiveRecord
         end
 
         sup = active_record_super
-        if sup.in?([Base, Model]) || sup.abstract_class?
+        if sup == Base || sup == Model || sup.abstract_class?
           self
         else
           sup.base_class
diff --git a/activerecord/lib/active_record/railties/databases.rake b/activerecord/lib/active_record/railties/databases.rake
index 6bb0c39b79..e0659700b6 100644
--- a/activerecord/lib/active_record/railties/databases.rake
+++ b/activerecord/lib/active_record/railties/databases.rake
@@ -1,4 +1,3 @@
-require 'active_support/core_ext/object/inclusion'
 require 'active_record'
 
 db_namespace = namespace :db do
diff --git a/activerecord/lib/active_record/tasks/database_tasks.rb b/activerecord/lib/active_record/tasks/database_tasks.rb
index fb3dfc2730..b41cc68b6a 100644
--- a/activerecord/lib/active_record/tasks/database_tasks.rb
+++ b/activerecord/lib/active_record/tasks/database_tasks.rb
@@ -115,7 +115,7 @@ module ActiveRecord
       end
 
       def local_database?(configuration)
-        configuration['host'].in?(LOCAL_HOSTS) || configuration['host'].blank?
+        configuration['host'].blank? || LOCAL_HOSTS.include?(configuration['host'])
       end
     end
   end