BUG: $all and $elemMatch fails on nested elements

[steffenmllr]

Hey there. first off: awesome stuff you did with mingo. However I encountered a bug while querying a nested array using $all and $elemMatch. I setup a testcase to illustrate the issue:

test("elemMatch on nested elements", function () {

  var testobject = [{
      user: { username: 'User1', projects: [{ name: "Project 1", rating: { complexity: 6 }}, { name: "Project 2", rating: { complexity: 2 }}] }
  },{
      user: { username: 'User2', projects: [{ name: "Project 1", rating: { complexity: 6 }}, { name: "Project 2", rating: { complexity: 8 }}] }
  }],
  query = {
    'user.projects': {
      "$all": [{
        "$elemMatch": {
          'rating.complexity': { '$gt' : 6 }
        }
      }]
    }
  };
  // It should return one user object
  ok(Mingo.compile(query).test(testobject));

});

Expected behavior: http://docs.mongodb.org/manual/reference/operator/query/all/#use-all-with-elemmatch

[steffenmllr]

Awesome. I'll check if it solves my problems. Btw. do you know https://github.com/meteor/meteor/blob/devel/packages/minimongo and https://github.com/louischatriot/nedb ?

It's another implementation of the same thing

[kofrasa]

Hi Steffen, am glad you find mingo useful and thanks for the report. I have resolved this bug and made a few corrections to your test case. The test function works per object instead of a collection. The find function is more appropriate instead.

var data = [{
      user: { username: 'User1', projects: [{ name: "Project 1", rating: { complexity: 6 }}, { name: "Project 2", rating: { complexity: 2 }}] }
    },{
      user: { username: 'User2', projects: [{ name: "Project 1", rating: { complexity: 6 }}, { name: "Project 2", rating: { complexity: 8 }}] }
    }];
    var query = {
      'user.projects': {
        "$all": [{
          "$elemMatch": {
            'rating.complexity': { '$gt' : 6 }
          }
        }]
      }
    };
    // It should return one user object
    var result = Mingo.find(data, query).count();
    equal(1, result, "can match using $all with $elemMatch on nested elements");

see commit f417c95