Major - P3 The query parser should disallow use of $text inside $elemMatch. There is no functionality to match a $text predicate against a subdocument; $text predicates apply to the root of a document only.
Users receive the following cryptic error message when running an $elemMatch query that contains $text:
> db.foo.find({a:{$elemMatch:{b:1,$text:{$search:"hello"}}}})
error: {
"$err" : "Unable to execute query: error processing query: ns=test.foo limit=0 skip=0\nTree: a $elemMatch (obj)\n $and\n b == 1.0\n TEXT : query=hello, language=, tag=NULL\nSort: {}\nProj: {}\n planner returned error: failed to use text index to satisfy $text query (if text index is compound, are equality predicates given for all prefix fields?)",
"code" : 17007
}