$elemMatch behavior mismatch with MongoDB

Similar to #227, there seems to be another mismatch for $elemMatch compared to MongoDB behavior.

Specifying $elemMatch as a string is handled by sift when it should not be.

  it("should not handle $elemMatch with string value", () => {
    expect(
      sift({ responsible: { $elemMatch: "Poyan" } })({
        responsible: ["Poyan", "Marcus"],
      })
    ).toEqual(false);
  }); 

// --> test case fails, sift called with test-data returns true

Attempting to run the same query against MongoDB returns $elemMatch needs an Object, which is also what the documentation specifies.

https://docs.mongodb.com/manual/reference/operator/query/elemMatch/

Please advise.

[crcn]

This makes more sense, but I think it would be more consistent if it threw an error, like #227 does and like MongoDB does. What do you think? @crcn

Yes good idea 👍

[crcn]

of course!