Remove `klass` and `arel_table` as a dependency of `PredicateBuilder`

This class cares far too much about the internals of other parts of
Active Record. This is an attempt to break out a meaningful object which
represents the needs of the predicate builder. I'm not fully satisfied
with the name, but the general concept is an object which represents a
table, the associations to/from that table, and the types associated
with it. Many of these exist at the `ActiveRecord::Base` class level,
not as properties of the table itself, hence the need for another
object. Currently it provides these by holding a reference to the class,
but that will likely change in the future. This allows the predicate
builder to remain wholy concerned with building predicates.

/cc @mrgilman

1 files changed, 2 insertions, 1 deletions

diff --git a/activerecord/test/cases/relations_test.rb b/activerecord/test/cases/relations_test.rb
index 408b0ff6ab..edb2d7fa7d 100644
--- a/activerecord/test/cases/relations_test.rb
+++ b/activerecord/test/cases/relations_test.rb
@@ -1663,7 +1663,8 @@ class RelationTest < ActiveRecord::TestCase
   test 'using a custom table affects the wheres' do
     table_alias = Post.arel_table.alias('omg_posts')
 
-    predicate_builder = ActiveRecord::PredicateBuilder.new(Post, table_alias)
+    table_metadata = ActiveRecord::TableMetadata.new(Post, table_alias)
+    predicate_builder = ActiveRecord::PredicateBuilder.new(table_metadata)
     relation = ActiveRecord::Relation.new(Post, table_alias, predicate_builder)
     relation.where!(:foo => "bar")