In ASTJSON tests it's possible to include the following directive (in the input .sol file) to indicate that analysis failure is expected after the specified compilation state:

// ----
// failAfter: Parsed

Looks like isolest strips this directive when it updates test expectations and reformats the input file.

Steps to reproduce

1. Change something in fail_after_parsing_parseOnly.json so that the expectations do not match the output
2. Run isoltest --test=ASTJSON/fail_after_parsing --accept-updates.

The directive will disappear from the input file.