In error case, the condition “gotErr != test.err && gotPath !=
test.expectedPath” never fulfill because in this case both gotPath and
test.expectedPath always an empty string. So the err “err: `field "what?"
does not exist`” doesn’t get tasted. For example, if you change the value of
“err” to anything, the test still will pass. Also, since gotPath is empty
string in case of err, in the output error we probably don’t want to display
path.
