Remove :error_mode

test/integration/assign_test.rb

@@ -39,11 +39,10 @@ class AssignTest < Minitest::Test
     assert_match_syntax_error(/assign/, '{% assign foo not values %}.')
   end
 
-  def test_assign_uses_error_mode
+  def test_assign_throws_on_unsupported_syntax
     assert_match_syntax_error(
       "Expected dotdot but found pipe",
       "{% assign foo = ('X' | downcase) %}",
-      error_mode: :rigid,
     )
   end