fix polymorphic joins with rails > 5.2

lib/ransack/adapters/active_record/context.rb

@@ -326,7 +326,6 @@ module Ransack
             found_association = jd.instance_variable_get(:@join_root).children.last
           end
 
-
           @associations_pot[found_association] = parent
 
           # TODO maybe we dont need to push associations here, we could loop
@@ -337,14 +336,11 @@ module Ransack
           if ::ActiveRecord::VERSION::STRING > Constants::RAILS_5_2_0
             @join_dependency.send(:construct_tables!, jd.instance_variable_get(:@join_root))
           else
-            @join_dependency.send(
-              :construct_tables!, jd.instance_variable_get(:@join_root), found_association
-            )
+            @join_dependency.send(:construct_tables!, jd.instance_variable_get(:@join_root), found_association)
           end
 
           # Leverage the stashed association functionality in AR
           @object = @object.joins(jd)
-
           found_association
         end
 

polyamorous/lib/polyamorous.rb

@@ -19,6 +19,11 @@ if defined?(::ActiveRecord)
     require "polyamorous/activerecord_#{ar_version}_ruby_2/#{file}"
   end
 
+  if ar_version >= "5.2.0"
+    require "polyamorous/activerecord_#{ar_version}_ruby_2/reflection.rb"
+    ::ActiveRecord::Reflection::AbstractReflection.send(:prepend, Polyamorous::ReflectionExtensions)
+  end
+
   Polyamorous::JoinDependency.send(:prepend, Polyamorous::JoinDependencyExtensions)
   Polyamorous::JoinDependency.singleton_class.send(:prepend, Polyamorous::JoinDependencyExtensions::ClassMethods)
   Polyamorous::JoinAssociation.send(:prepend, Polyamorous::JoinAssociationExtensions)

polyamorous/lib/polyamorous/activerecord_5.1_ruby_2/join_association.rb

@@ -7,8 +7,7 @@ module Polyamorous
       base.class_eval { attr_reader :join_type }
     end
 
-    def initialize(reflection, children, polymorphic_class = nil,
-                   join_type = Arel::Nodes::InnerJoin)
+    def initialize(reflection, children, polymorphic_class = nil, join_type = Arel::Nodes::InnerJoin)
       @join_type = join_type
       if polymorphic_class && ::ActiveRecord::Base > polymorphic_class
         swapping_reflection_klass(reflection, polymorphic_class) do |reflection|

polyamorous/lib/polyamorous/activerecord_5.2.0_ruby_2/join_association.rb

@@ -7,8 +7,7 @@ module Polyamorous
       base.class_eval { attr_reader :join_type }
     end
 
-    def initialize(reflection, children, alias_tracker, polymorphic_class = nil,
-      join_type = Arel::Nodes::InnerJoin)
+    def initialize(reflection, children, alias_tracker, polymorphic_class = nil, join_type = Arel::Nodes::InnerJoin)
       @join_type = join_type
       if polymorphic_class && ::ActiveRecord::Base > polymorphic_class
         swapping_reflection_klass(reflection, polymorphic_class) do |reflection|
@@ -23,7 +22,7 @@ module Polyamorous
     def build_constraint(klass, table, key, foreign_table, foreign_key)
       if reflection.polymorphic?
         super(klass, table, key, foreign_table, foreign_key)
-        .and(foreign_table[reflection.foreign_type].eq(reflection.klass.name))
+          .and(foreign_table[reflection.foreign_type].eq(reflection.klass.name))
       else
         super(klass, table, key, foreign_table, foreign_key)
       end

polyamorous/lib/polyamorous/activerecord_5.2.0_ruby_2/join_dependency.rb

@@ -38,7 +38,6 @@ module Polyamorous
     # passing an additional argument, `join_type`, to #join_constraints.
     #
     def join_constraints(outer_joins, join_type)
-      @alias_tracker = alias_tracker
       joins = join_root.children.flat_map { |child|
         if join_type == Arel::Nodes::OuterJoin
           make_polyamorous_left_outer_joins join_root, child

polyamorous/lib/polyamorous/activerecord_5.2.0_ruby_2/reflection.rb

@@ -0,0 +1,12 @@
+module Polyamorous
+  module ReflectionExtensions
+    def build_join_constraint(table, foreign_table)
+      if polymorphic?
+        super(table, foreign_table)
+        .and(foreign_table[foreign_type].eq(klass.name))
+      else
+        super(table, foreign_table)
+      end
+    end
+  end
+end

polyamorous/lib/polyamorous/activerecord_5.2.1_ruby_2/join_association.rb

@@ -18,14 +18,5 @@ module Polyamorous
         super(reflection, children)
       end
     end
-
-    def build_constraint(klass, table, key, foreign_table, foreign_key)
-      if reflection.polymorphic?
-        super(klass, table, key, foreign_table, foreign_key)
-        .and(foreign_table[reflection.foreign_type].eq(reflection.klass.name))
-      else
-        super(klass, table, key, foreign_table, foreign_key)
-      end
-    end
   end
 end

polyamorous/lib/polyamorous/activerecord_5.2.1_ruby_2/join_dependency.rb

@@ -3,7 +3,6 @@
 module Polyamorous
   module JoinDependencyExtensions
     # Replaces ActiveRecord::Associations::JoinDependency#build
-    #
     def build(associations, base_klass)
       associations.map do |name, right|
         if name.is_a? Join
@@ -30,6 +29,15 @@ module Polyamorous
       end
     end
 
+    private
+      def make_constraints(parent, child, join_type = Arel::Nodes::OuterJoin)
+        foreign_table = parent.table
+        foreign_klass = parent.base_klass
+        join_type = child.join_type || join_type if join_type == Arel::Nodes::InnerJoin
+        joins = child.join_constraints(foreign_table, foreign_klass, join_type, alias_tracker)
+        joins.concat child.children.flat_map { |c| make_constraints(child, c, join_type) }
+      end
+
     module ClassMethods
       # Prepended before ActiveRecord::Associations::JoinDependency#walk_tree
       #

polyamorous/lib/polyamorous/activerecord_5.2.1_ruby_2/reflection.rb

@@ -0,0 +1,2 @@
+# active_record_5.2.1_ruby_2/reflection.rb
+require 'polyamorous/activerecord_5.2.0_ruby_2/reflection'

ransack.gemspec

@@ -28,6 +28,7 @@ Gem::Specification.new do |s|
   s.add_development_dependency 'pg', '~> 0.21'
   s.add_development_dependency 'mysql2', '0.3.20'
   s.add_development_dependency 'pry', '0.10'
+  s.add_development_dependency 'byebug'
 
   s.files         = `git ls-files`.split("\n")
 

spec/spec_helper.rb

@@ -4,6 +4,7 @@ require 'faker'
 require 'ransack'
 require 'pry'
 require 'simplecov'
+require 'byebug'
 
 SimpleCov.start
 I18n.enforce_available_locales = false