add `ActiveRecord::Base.has_attribute?`

`has_attribute?` method to check wether a given attribute has been defined.

1 files changed, 13 insertions, 0 deletions

diff --git a/activerecord/test/cases/base_test.rb b/activerecord/test/cases/base_test.rb
index d961f4710e..3a9d60a79f 100644
--- a/activerecord/test/cases/base_test.rb
+++ b/activerecord/test/cases/base_test.rb
@@ -1345,6 +1345,19 @@ class BasicsTest < ActiveRecord::TestCase
                  Company.attribute_names
   end
 
+  def test_has_attribute
+    assert Company.has_attribute?('id')
+    assert Company.has_attribute?('type')
+    assert Company.has_attribute?('name')
+    assert_not Company.has_attribute?('lastname')
+    assert_not Company.has_attribute?('age')
+  end
+
+  def test_has_attribute_with_symbol
+    assert Company.has_attribute?(:id)
+    assert_not Company.has_attribute?(:age)
+  end
+
   def test_attribute_names_on_table_not_exists
     assert_equal [], NonExistentTable.attribute_names
   end