ActiveRecord/ActiveModel '#validate' alias for 'valid?'

It's unintuitive to call '#valid?' when you want to run validations but
don't care about the return value.

The alias in ActiveRecord isn't strictly necessary (the ActiveModel
alias is still in effect), but it clarifies.

activemodel/lib/active_model/validations.rb

@@ -285,6 +285,8 @@ module ActiveModel
     # Runs all the specified validations and returns +true+ if no errors were
     # added otherwise +false+.
     #
+    # Aliased as validate.
+    #
     #   class Person
     #     include ActiveModel::Validations
     #
@@ -319,6 +321,8 @@ module ActiveModel
       self.validation_context = current_context
     end
 
+    alias_method :validate, :valid?
+
     # Performs the opposite of <tt>valid?</tt>. Returns +true+ if errors were
     # added, +false+ otherwise.
     #

activemodel/test/cases/validations_test.rb

@@ -295,6 +295,15 @@ class ValidationsTest < ActiveModel::TestCase
     assert auto.valid?
   end
 
+  def test_validate
+    auto = Automobile.new
+
+    assert_empty auto.errors
+
+    auto.validate
+    assert_not_empty auto.errors
+  end
+
   def test_strict_validation_in_validates
     Topic.validates :title, strict: true, presence: true
     assert_raises ActiveModel::StrictValidationFailed do

activerecord/CHANGELOG.md

@@ -1,3 +1,9 @@
+*   Introduce `validate` as an alias for `valid?`.
+
+    This is more intuitive when you want to run validations but don't care about the return value.
+
+    *Henrik Nyh*
+
 *   Create indexes inline in CREATE TABLE for MySQL.
 
     This is important, because adding an index on a temporary table after it has been created

activerecord/lib/active_record/validations.rb

@@ -60,6 +60,8 @@ module ActiveRecord
     # Runs all the validations within the specified context. Returns +true+ if
     # no errors are found, +false+ otherwise.
     #
+    # Aliased as validate.
+    #
     # If the argument is +false+ (default is +nil+), the context is set to <tt>:create</tt> if
     # <tt>new_record?</tt> is +true+, and to <tt>:update</tt> if it is not.
     #
@@ -71,6 +73,8 @@ module ActiveRecord
       errors.empty? && output
     end
 
+    alias_method :validate, :valid?
+
   protected
 
     def perform_validations(options={}) # :nodoc:

activerecord/test/cases/validations_test.rb

@@ -52,6 +52,21 @@ class ValidationsTest < ActiveRecord::TestCase
     assert r.save(:context => :special_case)
   end
 
+  def test_validate
+    r = WrongReply.new
+
+    r.validate
+    assert_empty r.errors[:author_name]
+
+    r.validate(:special_case)
+    assert_not_empty r.errors[:author_name]
+
+    r.author_name = "secret"
+
+    r.validate(:special_case)
+    assert_empty r.errors[:author_name]
+  end
+
   def test_invalid_record_exception
     assert_raise(ActiveRecord::RecordInvalid) { WrongReply.create! }
     assert_raise(ActiveRecord::RecordInvalid) { WrongReply.new.save! }