Merge scoped :joins together instead of overwriting them. May expose scoping bugs in your code!

[#501 state:resolved]
Signed-off-by: NJeremy Kemper <jeremy@bitsweat.net>

activerecord/lib/active_record/associations.rb

@@ -1599,7 +1599,7 @@ def construct_finder_sql_with_included_associations(options, join_dependency)
           sql = "SELECT #{column_aliases(join_dependency)} FROM #{(scope && scope[:from]) || options[:from] || quoted_table_name} "
           sql << join_dependency.join_associations.collect{|join| join.association_join }.join
 
-          add_joins!(sql, options, scope)
+          add_joins!(sql, options[:joins], scope)
           add_conditions!(sql, options[:conditions], scope)
           add_limited_ids_condition!(sql, options, join_dependency) if !using_limitable_reflections?(join_dependency.reflections) && ((scope && scope[:limit]) || options[:limit])
 
@@ -1655,7 +1655,7 @@ def construct_finder_sql_for_association_limiting(options, join_dependency)
 
           if is_distinct
             sql << distinct_join_associations.collect { |assoc| assoc.association_join }.join
-            add_joins!(sql, options, scope)
+            add_joins!(sql, options[:joins], scope)
           end
 
           add_conditions!(sql, options[:conditions], scope)

activerecord/lib/active_record/base.rb

@@ -1549,7 +1549,7 @@ def construct_finder_sql(options)
           sql  = "SELECT #{options[:select] || (scope && scope[:select]) || ((options[:joins] || (scope && scope[:joins])) && quoted_table_name + '.*') || '*'} "
           sql << "FROM #{(scope && scope[:from]) || options[:from] || quoted_table_name} "
 
-          add_joins!(sql, options, scope)
+          add_joins!(sql, options[:joins], scope)
           add_conditions!(sql, options[:conditions], scope)
 
           add_group!(sql, options[:group], scope)
@@ -1565,6 +1565,22 @@ def merge_includes(first, second)
          (safe_to_array(first) + safe_to_array(second)).uniq
         end
 
+        def merge_joins(first, second)
+          if first.is_a?(String) && second.is_a?(String)
+            "#{first} #{second}"
+          elsif first.is_a?(String) || second.is_a?(String)
+            if first.is_a?(String)
+              join_dependency = ActiveRecord::Associations::ClassMethods::InnerJoinDependency.new(self, second, nil)
+              "#{first} #{join_dependency.join_associations.collect { |assoc| assoc.association_join }.join}"
+            else
+              join_dependency = ActiveRecord::Associations::ClassMethods::InnerJoinDependency.new(self, first, nil)
+              "#{join_dependency.join_associations.collect { |assoc| assoc.association_join }.join} #{second}"
+            end
+          else
+            (safe_to_array(first) + safe_to_array(second)).uniq
+          end
+        end
+
         # Object#to_a is deprecated, though it does have the desired behavior
         def safe_to_array(o)
           case o
@@ -1620,16 +1636,15 @@ def add_lock!(sql, options, scope = :auto)
         end
 
         # The optional scope argument is for the current <tt>:find</tt> scope.
-        def add_joins!(sql, options, scope = :auto)
+        def add_joins!(sql, joins, scope = :auto)
           scope = scope(:find) if :auto == scope
-          [(scope && scope[:joins]), options[:joins]].each do |join|
-            case join
-            when Symbol, Hash, Array
-              join_dependency = ActiveRecord::Associations::ClassMethods::InnerJoinDependency.new(self, join, nil)
-              sql << " #{join_dependency.join_associations.collect { |assoc| assoc.association_join }.join} "
-            else
-              sql << " #{join} "
-            end
+          merged_joins = scope && scope[:joins] && joins ? merge_joins(scope[:joins], joins) : (joins || scope && scope[:joins])
+          case merged_joins
+          when Symbol, Hash, Array
+            join_dependency = ActiveRecord::Associations::ClassMethods::InnerJoinDependency.new(self, merged_joins, nil)
+            sql << " #{join_dependency.join_associations.collect { |assoc| assoc.association_join }.join} "
+          when String
+            sql << " #{merged_joins} "
           end
         end
 
@@ -1879,6 +1894,8 @@ def with_scope(method_scoping = {}, action = :merge, &block)
                         hash[method][key] = merge_conditions(params[key], hash[method][key])
                       elsif key == :include && merge
                         hash[method][key] = merge_includes(hash[method][key], params[key]).uniq
+                      elsif key == :joins && merge
+                        hash[method][key] = merge_joins(params[key], hash[method][key])
                       else
                         hash[method][key] = hash[method][key] || params[key]
                       end

activerecord/lib/active_record/calculations.rb

@@ -188,7 +188,7 @@ def construct_calculation_sql(operation, column_name, options) #:nodoc:
           end
 
           joins = ""
-          add_joins!(joins, options, scope)
+          add_joins!(joins, options[:joins], scope)
 
           if merged_includes.any?
             join_dependency = ActiveRecord::Associations::ClassMethods::JoinDependency.new(self, merged_includes, joins)

activerecord/test/cases/method_scoping_test.rb

 require "cases/helper"
+require 'models/author'
 require 'models/developer'
 require 'models/project'
 require 'models/comment'
@@ -6,7 +7,7 @@
 require 'models/category'
 
 class MethodScopingTest < ActiveRecord::TestCase
-  fixtures :developers, :projects, :comments, :posts, :developers_projects
+  fixtures :authors, :developers, :projects, :comments, :posts, :developers_projects
 
   def test_set_conditions
     Developer.with_scope(:find => { :conditions => 'just a test...' }) do
@@ -97,6 +98,46 @@ def test_scoped_find_joins
     assert_equal developers(:david).attributes, scoped_developers.first.attributes
   end
 
+  def test_scoped_find_using_new_style_joins
+    scoped_developers = Developer.with_scope(:find => { :joins => :projects }) do
+      Developer.find(:all, :conditions => 'projects.id = 2')
+    end
+    assert scoped_developers.include?(developers(:david))
+    assert !scoped_developers.include?(developers(:jamis))
+    assert_equal 1, scoped_developers.size
+    assert_equal developers(:david).attributes, scoped_developers.first.attributes
+  end
+
+  def test_scoped_find_merges_old_style_joins
+    scoped_authors = Author.with_scope(:find => { :joins => 'INNER JOIN posts ON authors.id = posts.author_id ' }) do
+      Author.find(:all, :select => 'DISTINCT authors.*', :joins => 'INNER JOIN comments ON posts.id = comments.post_id', :conditions => 'comments.id = 1')
+    end
+    assert scoped_authors.include?(authors(:david))
+    assert !scoped_authors.include?(authors(:mary))
+    assert_equal 1, scoped_authors.size
+    assert_equal authors(:david).attributes, scoped_authors.first.attributes
+  end
+
+  def test_scoped_find_merges_new_style_joins
+    scoped_authors = Author.with_scope(:find => { :joins => :posts }) do
+      Author.find(:all, :select => 'DISTINCT authors.*', :joins => :comments, :conditions => 'comments.id = 1')
+    end
+    assert scoped_authors.include?(authors(:david))
+    assert !scoped_authors.include?(authors(:mary))
+    assert_equal 1, scoped_authors.size
+    assert_equal authors(:david).attributes, scoped_authors.first.attributes
+  end
+
+  def test_scoped_find_merges_new_and_old_style_joins
+    scoped_authors = Author.with_scope(:find => { :joins => :posts }) do
+      Author.find(:all, :select => 'DISTINCT authors.*', :joins => 'JOIN comments ON posts.id = comments.post_id', :conditions => 'comments.id = 1')
+    end
+    assert scoped_authors.include?(authors(:david))
+    assert !scoped_authors.include?(authors(:mary))
+    assert_equal 1, scoped_authors.size
+    assert_equal authors(:david).attributes, scoped_authors.first.attributes
+  end
+
   def test_scoped_count_include
     # with the include, will retrieve only developers for the given project
     Developer.with_scope(:find => { :include => :projects }) do
@@ -152,7 +193,7 @@ def test_ensure_that_method_scoping_is_correctly_restored
 end
 
 class NestedScopingTest < ActiveRecord::TestCase
-  fixtures :developers, :projects, :comments, :posts
+  fixtures :authors, :developers, :projects, :comments, :posts
 
   def test_merge_options
     Developer.with_scope(:find => { :conditions => 'salary = 80000' }) do
@@ -357,6 +398,42 @@ def test_ensure_that_method_scoping_is_correctly_restored
       assert_equal scoped_methods, Developer.instance_eval('current_scoped_methods')
     end
   end
+
+  def test_nested_scoped_find_merges_old_style_joins
+    scoped_authors = Author.with_scope(:find => { :joins => 'INNER JOIN posts ON authors.id = posts.author_id' }) do
+      Author.with_scope(:find => { :joins => 'INNER JOIN comments ON posts.id = comments.post_id' }) do
+        Author.find(:all, :select => 'DISTINCT authors.*', :conditions => 'comments.id = 1')
+      end
+    end
+    assert scoped_authors.include?(authors(:david))
+    assert !scoped_authors.include?(authors(:mary))
+    assert_equal 1, scoped_authors.size
+    assert_equal authors(:david).attributes, scoped_authors.first.attributes
+  end
+
+  def test_nested_scoped_find_merges_new_style_joins
+    scoped_authors = Author.with_scope(:find => { :joins => :posts }) do
+      Author.with_scope(:find => { :joins => :comments }) do
+        Author.find(:all, :select => 'DISTINCT authors.*', :conditions => 'comments.id = 1')
+      end
+    end
+    assert scoped_authors.include?(authors(:david))
+    assert !scoped_authors.include?(authors(:mary))
+    assert_equal 1, scoped_authors.size
+    assert_equal authors(:david).attributes, scoped_authors.first.attributes
+  end
+
+  def test_nested_scoped_find_merges_new_and_old_style_joins
+    scoped_authors = Author.with_scope(:find => { :joins => :posts }) do
+      Author.with_scope(:find => { :joins => 'INNER JOIN comments ON posts.id = comments.post_id' }) do
+        Author.find(:all, :select => 'DISTINCT authors.*', :joins => '', :conditions => 'comments.id = 1')
+      end
+    end
+    assert scoped_authors.include?(authors(:david))
+    assert !scoped_authors.include?(authors(:mary))
+    assert_equal 1, scoped_authors.size
+    assert_equal authors(:david).attributes, scoped_authors.first.attributes
+  end
 end
 
 class HasManyScopingTest< ActiveRecord::TestCase