Merge pull request #10168 from neerajdotname/simple_improvements

Simple improvements

3 files changed, 39 insertions, 5 deletions

diff --git a/activerecord/lib/active_record/associations/join_dependency.rb b/activerecord/lib/active_record/associations/join_dependency.rb
index d3ceecb090..28e081c03c 100644
--- a/activerecord/lib/active_record/associations/join_dependency.rb
+++ b/activerecord/lib/active_record/associations/join_dependency.rb
@@ -7,6 +7,27 @@ module ActiveRecord
 
       attr_reader :join_parts, :reflections, :alias_tracker, :base_klass
 
+      # base is the base class on which operation is taking place.
+      # associations is the list of associations which are joined using hash, symbol or array.
+      # joins is the list of all string join commnads and arel nodes.
+      #
+      #  Example :
+      #
+      #  class Physician < ActiveRecord::Base
+      #    has_many :appointments
+      #    has_many :patients, through: :appointments
+      #  end
+      #
+      #  If I execute `@physician.patients.to_a` then
+      #    base #=> Physician
+      #    associations #=> []
+      #    joins #=>  [#<Arel::Nodes::InnerJoin: ...]
+      #
+      #  However if I execute `Physician.joins(:appointments).to_a` then
+      #    base #=> Physician
+      #    associations #=> [:appointments]
+      #    joins #=>  []
+      #
       def initialize(base, associations, joins)
         @base_klass    = base
         @table_joins   = joins
@@ -58,6 +79,8 @@ module ActiveRecord
         records
       end
 
+      protected
+
       def remove_duplicate_results!(base, records, associations)
         case associations
         when Symbol, String
@@ -88,8 +111,6 @@ module ActiveRecord
         end
       end
 
-      protected
-
       def cache_joined_association(association)
         associations = []
         parent = association.parent
diff --git a/activerecord/lib/active_record/associations/join_dependency/join_association.rb b/activerecord/lib/active_record/associations/join_dependency/join_association.rb
index ae1b38ff86..e4d17451dc 100644
--- a/activerecord/lib/active_record/associations/join_dependency/join_association.rb
+++ b/activerecord/lib/active_record/associations/join_dependency/join_association.rb
@@ -123,6 +123,21 @@ module ActiveRecord
           manager
         end
 
+        #  Builds equality condition.
+        #
+        #  Example:
+        #
+        #  class Physician < ActiveRecord::Base
+        #    has_many :appointments
+        #  end
+        #
+        #  If I execute `Physician.joins(:appointments).to_a` then
+        #    reflection    #=> #<ActiveRecord::Reflection::AssociationReflection @macro=:has_many ...>
+        #    table         #=> #<Arel::Table @name="appointments" ...>
+        #    key           #=>  physician_id
+        #    foreign_table #=> #<Arel::Table @name="physicians" ...>
+        #    foreign_key   #=> id
+        #
         def build_constraint(reflection, table, key, foreign_table, foreign_key)
           constraint = table[key].eq(foreign_table[foreign_key])
 
diff --git a/activerecord/lib/active_record/relation/query_methods.rb b/activerecord/lib/active_record/relation/query_methods.rb
index 257221174b..06a220216a 100644
--- a/activerecord/lib/active_record/relation/query_methods.rb
+++ b/activerecord/lib/active_record/relation/query_methods.rb
@@ -934,9 +934,7 @@ module ActiveRecord
       association_joins         = buckets[:association_join] || []
       stashed_association_joins = buckets[:stashed_join] || []
       join_nodes                = (buckets[:join_node] || []).uniq
-      string_joins              = (buckets[:string_join] || []).map { |x|
-        x.strip
-      }.uniq
+      string_joins              = (buckets[:string_join] || []).map { |x| x.strip }.uniq
 
       join_list = join_nodes + custom_join_ast(manager, string_joins)