Refactor Active Record to let Arel manage bind params

A common source of bugs and code bloat within Active Record has been the
need for us to maintain the list of bind values separately from the AST
they're associated with. This makes any sort of AST manipulation
incredibly difficult, as any time we want to potentially insert or
remove an AST node, we need to traverse the entire tree to find where
the associated bind parameters are.

With this change, the bind parameters now live on the AST directly.
Active Record does not need to know or care about them until the final
AST traversal for SQL construction. Rather than returning just the SQL,
the Arel collector will now return both the SQL and the bind parameters.
At this point the connection adapter will have all the values that it
had before.

A bit of this code is janky and something I'd like to refactor later. In
particular, I don't like how we're handling associations in the
predicate builder, the special casing of `StatementCache::Substitute` in
`QueryAttribute`, or generally how we're handling bind value replacement
in the statement cache when prepared statements are disabled.

This also mostly reverts #26378, as it moved all the code into a
location that I wanted to delete.

/cc @metaskills @yahonda, this change will affect the adapters

Fixes #29766.
Fixes #29804.
Fixes #26541.
Close #28539.
Close #24769.
Close #26468.
Close #26202.

There are probably other issues/PRs that can be closed because of this
commit, but that's all I could find on the first few pages.

4 files changed, 35 insertions, 12 deletions

diff --git a/activerecord/lib/active_record/relation/predicate_builder/array_handler.rb b/activerecord/lib/active_record/relation/predicate_builder/array_handler.rb
index 85ec7d1428..ad617365fc 100644
--- a/activerecord/lib/active_record/relation/predicate_builder/array_handler.rb
+++ b/activerecord/lib/active_record/relation/predicate_builder/array_handler.rb
@@ -19,7 +19,11 @@ module ActiveRecord
           case values.length
           when 0 then NullPredicate
           when 1 then predicate_builder.build(attribute, values.first)
-          else attribute.in(values)
+          else
+            bind_values = values.map do |v|
+              predicate_builder.build_bind_attribute(attribute.name, v)
+            end
+            attribute.in(bind_values)
           end
 
         unless nils.empty?
@@ -31,8 +35,6 @@ module ActiveRecord
         array_predicates.inject(&:or)
       end
 
-      # TODO Change this to private once we've dropped Ruby 2.2 support.
-      # Workaround for Ruby 2.2 "private attribute?" warning.
       protected
 
         attr_reader :predicate_builder
diff --git a/activerecord/lib/active_record/relation/predicate_builder/base_handler.rb b/activerecord/lib/active_record/relation/predicate_builder/base_handler.rb
index 632c68a103..112821135f 100644
--- a/activerecord/lib/active_record/relation/predicate_builder/base_handler.rb
+++ b/activerecord/lib/active_record/relation/predicate_builder/base_handler.rb
@@ -11,8 +11,6 @@ module ActiveRecord
         predicate_builder.build(attribute, value.id)
       end
 
-      # TODO Change this to private once we've dropped Ruby 2.2 support.
-      # Workaround for Ruby 2.2 "private attribute?" warning.
       protected
 
         attr_reader :predicate_builder
diff --git a/activerecord/lib/active_record/relation/predicate_builder/basic_object_handler.rb b/activerecord/lib/active_record/relation/predicate_builder/basic_object_handler.rb
index a17cf30ffd..34db266f05 100644
--- a/activerecord/lib/active_record/relation/predicate_builder/basic_object_handler.rb
+++ b/activerecord/lib/active_record/relation/predicate_builder/basic_object_handler.rb
@@ -3,9 +3,18 @@
 module ActiveRecord
   class PredicateBuilder
     class BasicObjectHandler # :nodoc:
+      def initialize(predicate_builder)
+        @predicate_builder = predicate_builder
+      end
+
       def call(attribute, value)
-        attribute.eq(value)
+        bind = predicate_builder.build_bind_attribute(attribute.name, value)
+        attribute.eq(bind)
       end
+
+      protected
+
+        attr_reader :predicate_builder
     end
   end
 end
diff --git a/activerecord/lib/active_record/relation/predicate_builder/range_handler.rb b/activerecord/lib/active_record/relation/predicate_builder/range_handler.rb
index 072e238306..6d16579708 100644
--- a/activerecord/lib/active_record/relation/predicate_builder/range_handler.rb
+++ b/activerecord/lib/active_record/relation/predicate_builder/range_handler.rb
@@ -3,25 +3,39 @@
 module ActiveRecord
   class PredicateBuilder
     class RangeHandler # :nodoc:
-      RangeWithBinds = Struct.new(:begin, :end, :exclude_end?)
+      class RangeWithBinds < Struct.new(:begin, :end)
+        def exclude_end?
+          false
+        end
+      end
+
+      def initialize(predicate_builder)
+        @predicate_builder = predicate_builder
+      end
 
       def call(attribute, value)
+        begin_bind = predicate_builder.build_bind_attribute(attribute.name, value.begin)
+        end_bind = predicate_builder.build_bind_attribute(attribute.name, value.end)
         if value.begin.respond_to?(:infinite?) && value.begin.infinite?
           if value.end.respond_to?(:infinite?) && value.end.infinite?
             attribute.not_in([])
           elsif value.exclude_end?
-            attribute.lt(value.end)
+            attribute.lt(end_bind)
           else
-            attribute.lteq(value.end)
+            attribute.lteq(end_bind)
           end
         elsif value.end.respond_to?(:infinite?) && value.end.infinite?
-          attribute.gteq(value.begin)
+          attribute.gteq(begin_bind)
         elsif value.exclude_end?
-          attribute.gteq(value.begin).and(attribute.lt(value.end))
+          attribute.gteq(begin_bind).and(attribute.lt(end_bind))
         else
-          attribute.between(value)
+          attribute.between(RangeWithBinds.new(begin_bind, end_bind))
         end
       end
+
+      protected
+
+        attr_reader :predicate_builder
     end
   end
 end