Thanks Eli Zaretskii and Randy Taylor for your remarks. An undated patch is attached. On 2 November 2024 at 20:48 +01, Randy Taylor wrote: > […] Unless I am missing something, the variables should reset > automatically. They are only changed in the context of the test. > > How are you running them that you are seeing otherwise? I now am using the command line but, if I evaluate the tests (C-xC-e) and then run them with M-x ert, the variable 'rust-ts-mode-fontify-number-suffix-as-type' is not reset to its original value. Best, C.