Follow new behavior of Rails 6.1

`ActiveModel::Errors#messages` now only returns error attributes.

test/activemodel_validation_test.rb

@@ -265,7 +265,11 @@ def email_present?
     # valid.
     it "is valid" do
       _(form.validate({ username: "not yo", email: "bla" })).must_equal true
-      _(form.errors.messages).must_equal({:username=>[], :email=>[]})
+      if self.class.rails_greater_6_0?
+        _(form.errors.messages).must_equal({})
+      else
+        _(form.errors.messages).must_equal({:username=>[], :email=>[]})
+      end
       if self.class.rails5?
         _(form.errors.details.inspect).must_equal "{}"
       end
@@ -312,7 +316,11 @@ def email_present?
       _(form.errors.messages).must_equal(email: ["can't be blank", "fill it out!"], username: ["not ok", "must be yo"], policy: ["error_text", "another error"])
       # keep added errors after validate
       _(form.validate(username: "username", email: "[email protected]")).must_equal false
-      _(form.errors.messages).must_equal(policy: ["error_text", "another error"], username: [], email: [])
+      if self.class.rails_greater_6_0?
+        _(form.errors.messages).must_equal(policy: ["error_text", "another error"])
+      else
+        _(form.errors.messages).must_equal(policy: ["error_text", "another error"], username: [], email: [])
+      end
       _(form.errors.added?(:policy, "error_text")).must_equal true
       _(form.errors.added?(:policy, "another error")).must_equal true
       _(form.errors.details).must_equal(

test/test_helper.rb

@@ -39,6 +39,10 @@ class Album < ActiveRecord::Base
 load "#{File.dirname(__FILE__)}/support/schema.rb"
 
 Minitest::Spec.class_eval do
+  def self.rails_greater_6_0?
+    (::ActiveModel::VERSION::MAJOR == 6 and ::ActiveModel::VERSION::MINOR >= 1) || (::ActiveModel::VERSION::MAJOR >= 7)
+  end
+
   def self.rails5?
     ::ActiveModel::VERSION::MAJOR.in? [5,6]
   end