Check attributes of schema.rb to decide whether to convert or not.

lib/rails/convert_dynamic_finders.rb

@@ -8,10 +8,23 @@
     scoped_by_... => where(...)
     find_or_initialize_by_... => find_or_initialize_by(...)
     find_or_create_by_... => find_or_create_by(...)
+
+But it keeps custom methods like dynamic finders intact.
   EOF
 
+  attributes = ["id"]
+  within_file 'db/schema.rb' do
+    within_node type: 'block', caller: {type: 'send', message: 'create_table'} do
+      with_node type: 'send', receiver: 't' do
+        attributes << node.arguments.first.to_value
+      end
+    end
+  end
+
   helper_method :dynamic_finder_to_hash do |prefix|
-    fields = node.message.to_s[prefix.length..-1].split("_and_")
+    fields = fields_of_dynamic_finder(prefix)
+    return nil if (fields & attributes) != fields
+
     if fields.length == node.arguments.length && :hash != node.arguments.first.type
       fields.length.times.map { |i|
         fields[i] + ": " + node.arguments[i].to_source
@@ -21,13 +34,17 @@
     end
   end
 
+  helper_method :fields_of_dynamic_finder do |prefix|
+    node.message.to_s[prefix.length..-1].split("_and_")
+  end
+
   if_gem 'rails', {gte: '3.0.0'}
 
   within_files '**/*.rb' do
     # find_all_by_... => where(...)
     with_node type: 'send', message: /^find_all_by_/ do
       hash_params = dynamic_finder_to_hash("find_all_by_")
-      replace_with add_receiver_if_necessary("where(#{hash_params})")
+      replace_with(add_receiver_if_necessary("where(#{hash_params})")) if hash_params
     end
 
     # find_by_... => where(...).first
@@ -36,20 +53,20 @@
         replace_with add_receiver_if_necessary("where(id: {{arguments}}).first")
       elsif :find_by_sql != node.message
         hash_params = dynamic_finder_to_hash("find_by_")
-        replace_with add_receiver_if_necessary("where(#{hash_params}).first")
+        replace_with(add_receiver_if_necessary("where(#{hash_params}).first")) if hash_params
       end
     end
 
     # find_last_by_... => where(...).last
     with_node type: 'send', message: /^find_last_by_/ do
       hash_params = dynamic_finder_to_hash("find_last_by_")
-      replace_with add_receiver_if_necessary("where(#{hash_params}).last")
+      replace_with(add_receiver_if_necessary("where(#{hash_params}).last")) if hash_params
     end
 
     # scoped_by_... => where(...)
     with_node type: 'send', message: /^scoped_by_/ do
       hash_params = dynamic_finder_to_hash("scoped_by_")
-      replace_with add_receiver_if_necessary("where(#{hash_params})")
+      replace_with(add_receiver_if_necessary("where(#{hash_params})")) if hash_params
     end
   end
 
@@ -59,13 +76,13 @@
     # find_or_initialize_by_... => find_or_initialize_by(...)
     with_node type: 'send', message: /^find_or_initialize_by_/ do
       hash_params = dynamic_finder_to_hash("find_or_initialize_by_")
-      replace_with add_receiver_if_necessary("find_or_initialize_by(#{hash_params})")
+      replace_with(add_receiver_if_necessary("find_or_initialize_by(#{hash_params})")) if hash_params
     end
 
     # find_or_create_by_... => find_or_create_by(...)
     with_node type: 'send', message: /^find_or_create_by_/ do
       hash_params = dynamic_finder_to_hash("find_or_create_by_")
-      replace_with add_receiver_if_necessary("find_or_create_by(#{hash_params})")
+      replace_with(add_receiver_if_necessary("find_or_create_by(#{hash_params})")) if hash_params
     end
   end
 end

spec/rails/convert_dynamic_finders_spec.rb

@@ -7,70 +7,105 @@
   end
 
   describe 'with fakefs', fakefs: true do
+    let(:schema_content) {'
+ActiveRecord::Schema.define(version: 20140211112752) do
+  create_table "users", force: true do |t|
+    t.integer  "account_id",               index: true
+    t.string   "login"
+    t.string   "email"
+    t.datetime "created_at"
+    t.datetime "updated_at"
+    t.integer  "role",                      default: 0,     null: false
+    t.boolean  "admin",                     default: false, null: false
+    t.boolean  "active",                    default: false, null: false
+  end
+end
+    '}
+
     let(:post_model_content) {'
 class Post < ActiveRecord::Base
   def active_users
     User.find_all_by_email_and_active(email, true)
+    User.find_all_by_label_and_active(label, true)
     User.find_by_email_and_active(email, true)
+    User.find_by_label_and_active(label, true)
     User.find_last_by_email_and_active(email, true)
+    User.find_last_by_label_and_active(label, true)
     User.scoped_by_email_and_active(email, true)
+    User.scoped_by_label_and_active(label, true)
     User.find_by_sql(["select * from  users where email = ?", email])
     User.find_by_id(id)
+    User.find_by_label
     User.find_by_account_id(Account.find_by_email(account_email).id)
     User.find_or_create_by_email_and_login(parmas)
+    User.find_or_create_by_label(label)
     User.find_or_initialize_by_account_id(:account_id => account_id)
+    User.find_or_initialize_by_label(label)
   end
 
   def self.active_admins
-    find_all_by_role_and_active("admin", true)
+    User.find_all_by_role_and_active("admin", true)
   end
 end
     '}
     let(:post_model_rewritten_content) {'
 class Post < ActiveRecord::Base
   def active_users
     User.where(email: email, active: true)
+    User.find_all_by_label_and_active(label, true)
     User.where(email: email, active: true).first
+    User.find_by_label_and_active(label, true)
     User.where(email: email, active: true).last
+    User.find_last_by_label_and_active(label, true)
     User.where(email: email, active: true)
+    User.scoped_by_label_and_active(label, true)
     User.find_by_sql(["select * from  users where email = ?", email])
     User.where(id: id).first
+    User.find_by_label
     User.where(account_id: Account.where(email: account_email).first.id).first
     User.find_or_create_by(parmas)
+    User.find_or_create_by_label(label)
     User.find_or_initialize_by(:account_id => account_id)
+    User.find_or_initialize_by_label(label)
   end
 
   def self.active_admins
-    where(role: "admin", active: true)
+    User.where(role: "admin", active: true)
   end
 end
     '}
     let(:users_controller_content) {'
 class UsersController < ApplicationController
   def new
     @user = User.find_or_initialize_by_login_and_email(params[:user][:login], params[:user][:email])
+    @user = User.find_or_initialize_by_label(params[:user][:label])
   end
 
   def create
     @user = User.find_or_create_by_login_and_email(params[:user][:login], params[:user][:email])
+    @user = User.find_or_create_by_label(params[:user][:label])
   end
 end
     '}
     let(:users_controller_rewritten_content) {'
 class UsersController < ApplicationController
   def new
     @user = User.find_or_initialize_by(login: params[:user][:login], email: params[:user][:email])
+    @user = User.find_or_initialize_by_label(params[:user][:label])
   end
 
   def create
     @user = User.find_or_create_by(login: params[:user][:login], email: params[:user][:email])
+    @user = User.find_or_create_by_label(params[:user][:label])
   end
 end
     '}
 
     it 'converts' do
+      FileUtils.mkdir_p 'db'
       FileUtils.mkdir_p 'app/models'
       FileUtils.mkdir_p 'app/controllers'
+      File.write 'db/schema.rb', schema_content
       File.write 'app/models/post.rb', post_model_content
       File.write 'app/controllers/users_controller.rb', users_controller_content
       @rewriter.process