Spell spec is very simple way to define keys specs that check for misspelled keys in maps while keeping the maps open to unspecified keys that are not close misspellings of specified keys.
There is also a closed strict-keys spec that will fail for unrecognized keys.
spell-spec also has a warning mode, so it will only throw warnings when unknown and misspelled keys are detected.
One pain point I have found is that with stuff like this (closedmap) is that we have to define a spec testing for wrong keys, and then we have to define a spec for the correct keys (checking that the data conforms to the spec). It would be great if there was a “higher” level macro that let me get the “closed map” spec for free at the time of defining the macro for the “open map”