Make error message clearer that :on requires a symbol, not a string

The validation added in 5a3dc8092d19c816b0b1203945639cb91d065847 will
reject values for the `:on` option for after_commit and after_rollback
callbacks that are string values like `"create"`.

However, the error message says ":on conditions for after_commit and
after_rollback callbacks have to be one of create,destroy,update". That
looks like a string value *would* be valid.

This commit changes the error message to say ":on conditions for
after_commit and after_rollback callbacks have to be one of [:create,
:destroy, :update]", making it clearer that symbols are required.

1 files changed, 4 insertions, 0 deletions

diff --git a/activerecord/test/cases/transaction_callbacks_test.rb b/activerecord/test/cases/transaction_callbacks_test.rb
index b5ac1bdaf9..0f5caa52e3 100644
--- a/activerecord/test/cases/transaction_callbacks_test.rb
+++ b/activerecord/test/cases/transaction_callbacks_test.rb
@@ -371,10 +371,14 @@ class TransactionCallbacksTest < ActiveRecord::TestCase
 
   def test_after_rollback_callbacks_should_validate_on_condition
     assert_raise(ArgumentError) { Topic.after_rollback(on: :save) }
+    e = assert_raise(ArgumentError) { Topic.after_rollback(on: 'create') }
+    assert_match(/:on conditions for after_commit and after_rollback callbacks have to be one of \[:create, :destroy, :update\]/, e.message)
   end
 
   def test_after_commit_callbacks_should_validate_on_condition
     assert_raise(ArgumentError) { Topic.after_commit(on: :save) }
+    e = assert_raise(ArgumentError) { Topic.after_commit(on: 'create') }
+    assert_match(/:on conditions for after_commit and after_rollback callbacks have to be one of \[:create, :destroy, :update\]/, e.message)
   end
 
   def test_saving_a_record_with_a_belongs_to_that_specifies_touching_the_parent_should_call_callbacks_on_the_parent_object