Model.select takes a variable list of arguments.

This is a cleaner version of #6916.

Closes #3165.

activerecord/lib/active_record/relation/query_methods.rb

@@ -136,34 +136,35 @@ def references!(*args)
     # Second: Modifies the SELECT statement for the query so that only certain
     # fields are retrieved:
     #
-    #   >> Model.select(:field)
-    #   => [#<Model field:value>]
+    #   Model.select(:field)
+    #   # => [#<Model field:value>]
     #
     # Although in the above example it looks as though this method returns an
     # array, it actually returns a relation object and can have other query
     # methods appended to it, such as the other methods in ActiveRecord::QueryMethods.
     #
     # The argument to the method can also be an array of fields.
     #
-    #   >> Model.select([:field, :other_field, :and_one_more])
-    #   => [#<Model field: "value", other_field: "value", and_one_more: "value">]
+    #   Model.select(:field, :other_field, :and_one_more)
+    #   # => [#<Model field: "value", other_field: "value", and_one_more: "value">]
     #
     # Accessing attributes of an object that do not have fields retrieved by a select
     # will throw <tt>ActiveModel::MissingAttributeError</tt>:
     #
-    #   >> Model.select(:field).first.other_field
-    #   => ActiveModel::MissingAttributeError: missing attribute: other_field
-    def select(value = Proc.new)
+    #   Model.select(:field).first.other_field
+    #   # => ActiveModel::MissingAttributeError: missing attribute: other_field
+    def select(*fields)
       if block_given?
-        to_a.select { |*block_args| value.call(*block_args) }
+        to_a.select { |*block_args| yield(*block_args) }
       else
-        spawn.select!(value)
+        raise ArgumentError, 'Call this with at least one field' if fields.empty?
+        spawn.select!(*fields)
       end
     end
 
     # Like #select, but modifies relation in place.
-    def select!(value)
-      self.select_values += Array.wrap(value)
+    def select!(*fields)
+      self.select_values += fields.flatten
       self
     end
 

activerecord/test/cases/relations_test.rb

@@ -656,6 +656,14 @@ def test_delete_all_limit_error
     assert_raises(ActiveRecord::ActiveRecordError) { Author.limit(10).delete_all }
   end
 
+  def test_select_takes_a_variable_list_of_args
+    david = developers(:david)
+
+    developer = Developer.where(id: david.id).select(:name, :salary).first
+    assert_equal david.name, developer.name
+    assert_equal david.salary, developer.salary
+  end
+
   def test_select_argument_error
     assert_raises(ArgumentError) { Developer.select }
   end