Almost non-existing. A couple of excerpts from man page:

  {"a":1,"b":[true,false,null,"str"],"c":{"d":4,"e":5}}
  jshon [actions] < sample.json
  jshon -e c -> {"d":4,"e":5}
  jshon -e c -e d -u -p -e e -u -> 4 5

Yet this covers like ~50% of possible use cases for jq.