use ARel factory methods for building AST nodes

This abstracts us from the actual construction of the nodes

activerecord/test/cases/relation/predicate_builder_test.rb

@@ -5,10 +5,10 @@ module ActiveRecord
   class PredicateBuilderTest < ActiveRecord::TestCase
     def test_registering_new_handlers
       PredicateBuilder.register_handler(Regexp, proc do |column, value|
-        Arel::Nodes::InfixOperation.new('~', column, value.source)
+        Arel::Nodes::InfixOperation.new('~', column, Arel.sql(value.source))
       end)
 
-      assert_match %r{["`]topics["`].["`]title["`] ~ 'rails'}i, Topic.where(title: /rails/).to_sql
+      assert_match %r{["`]topics["`].["`]title["`] ~ rails}i, Topic.where(title: /rails/).to_sql
     end
   end
 end

activerecord/test/cases/relation/where_chain_test.rb

@@ -12,13 +12,13 @@ module ActiveRecord
     end
 
     def test_not_eq
-      expected = Arel::Nodes::NotEqual.new(Post.arel_table[@name], 'hello')
+      expected = Post.arel_table[@name].not_eq('hello')
       relation = Post.where.not(title: 'hello')
       assert_equal([expected], relation.where_values)
     end
 
     def test_not_null
-      expected = Arel::Nodes::NotEqual.new(Post.arel_table[@name], nil)
+      expected = Post.arel_table[@name].not_eq(nil)
       relation = Post.where.not(title: nil)
       assert_equal([expected], relation.where_values)
     end
@@ -30,13 +30,13 @@ module ActiveRecord
     end
 
     def test_not_in
-      expected = Arel::Nodes::NotIn.new(Post.arel_table[@name], %w[hello goodbye])
+      expected = Post.arel_table[@name].not_in(%w[hello goodbye])
       relation = Post.where.not(title: %w[hello goodbye])
       assert_equal([expected], relation.where_values)
     end
 
     def test_association_not_eq
-      expected = Arel::Nodes::NotEqual.new(Comment.arel_table[@name], 'hello')
+      expected = Comment.arel_table[@name].not_eq('hello')
       relation = Post.joins(:comments).where.not(comments: {title: 'hello'})
       assert_equal(expected.to_sql, relation.where_values.first.to_sql)
     end
@@ -44,20 +44,20 @@ module ActiveRecord
     def test_not_eq_with_preceding_where
       relation = Post.where(title: 'hello').where.not(title: 'world')
 
-      expected = Arel::Nodes::Equality.new(Post.arel_table[@name], 'hello')
+      expected = Post.arel_table[@name].eq('hello')
       assert_equal(expected, relation.where_values.first)
 
-      expected = Arel::Nodes::NotEqual.new(Post.arel_table[@name], 'world')
+      expected = Post.arel_table[@name].not_eq('world')
       assert_equal(expected, relation.where_values.last)
     end
 
     def test_not_eq_with_succeeding_where
       relation = Post.where.not(title: 'hello').where(title: 'world')
 
-      expected = Arel::Nodes::NotEqual.new(Post.arel_table[@name], 'hello')
+      expected = Post.arel_table[@name].not_eq('hello')
       assert_equal(expected, relation.where_values.first)
 
-      expected = Arel::Nodes::Equality.new(Post.arel_table[@name], 'world')
+      expected = Post.arel_table[@name].eq('world')
       assert_equal(expected, relation.where_values.last)
     end
 
@@ -76,17 +76,17 @@ module ActiveRecord
     def test_chaining_multiple
       relation = Post.where.not(author_id: [1, 2]).where.not(title: 'ruby on rails')
 
-      expected = Arel::Nodes::NotIn.new(Post.arel_table['author_id'], [1, 2])
+      expected = Post.arel_table['author_id'].not_in([1, 2])
       assert_equal(expected, relation.where_values[0])
 
-      expected = Arel::Nodes::NotEqual.new(Post.arel_table[@name], 'ruby on rails')
+      expected = Post.arel_table[@name].not_eq('ruby on rails')
       assert_equal(expected, relation.where_values[1])
     end
     
     def test_rewhere_with_one_condition
       relation = Post.where(title: 'hello').where(title: 'world').rewhere(title: 'alone')
 
-      expected = Arel::Nodes::Equality.new(Post.arel_table[@name], 'alone')
+      expected = Post.arel_table[@name].eq('alone')
       assert_equal 1, relation.where_values.size
       assert_equal expected, relation.where_values.first
     end
@@ -94,8 +94,8 @@ module ActiveRecord
     def test_rewhere_with_multiple_overwriting_conditions
       relation = Post.where(title: 'hello').where(body: 'world').rewhere(title: 'alone', body: 'again')
 
-      title_expected = Arel::Nodes::Equality.new(Post.arel_table['title'], 'alone')
+      title_expected = Post.arel_table['title'].eq('alone')
-      body_expected  = Arel::Nodes::Equality.new(Post.arel_table['body'], 'again')
+      body_expected  = Post.arel_table['body'].eq('again')
 
       assert_equal 2, relation.where_values.size
       assert_equal title_expected, relation.where_values.first
@@ -105,8 +105,8 @@ module ActiveRecord
     def test_rewhere_with_one_overwriting_condition_and_one_unrelated
       relation = Post.where(title: 'hello').where(body: 'world').rewhere(title: 'alone')
 
-      title_expected = Arel::Nodes::Equality.new(Post.arel_table['title'], 'alone')
+      title_expected = Post.arel_table['title'].eq('alone')
-      body_expected  = Arel::Nodes::Equality.new(Post.arel_table['body'], 'world')
+      body_expected  = Post.arel_table['body'].eq('world')
 
       assert_equal 2, relation.where_values.size
       assert_equal body_expected, relation.where_values.first