text: //
  //  $push acquired the possibility of sorting the resulting array as part of SERVER-8008. This
  //  test exercises such $sort clause from the shell user's perspective.
  //
  
  t = db.push_sort;
  t.drop();
  
  //
  // Valid Cases
  //
  
  // $slice amount is too large to kick in.
  t.save({_id: 1, x: [{a: 1}, {a: 2}]});
  t.update({_id: 1}, {$push: {x: {$each: [{a: 3}], $slice: -5, $sort: {a: 1}}}});
  assert.eq([{a: 1}, {a: 2}, {a: 3}], t.findOne({_id: 1}).x);
  
  // $slice amount kicks in using values of both the base doc and of the $each clause.
  t.save({_id: 2, x: [{a: 1}, {a: 3}]});
  t.update({_id: 2}, {$push: {x: {$each: [{a: 2}], $slice: -2, $sort: {a: 1}}}});
  assert.eq([{a: 2}, {a: 3}], t.findOne({_id: 2}).x);
  
  // $sort is descending and $slice is too large to kick in.
  t.save({_id: 3, x: [{a: 1}, {a: 3}]});
  t.update({_id: 3}, {$push: {x: {$each: [{a: 2}], $slice: -5, $sort: {a: -1}}}});
  assert.eq([{a: 3}, {a: 2}, {a: 1}], t.findOne({_id: 3}).x);
  
  // $sort is descending and $slice kicks in using values of both the base doc and of
  // the $each clause.
  t.save({_id: 4, x: [{a: 1}, {a: 3}]});
  t.update({_id: 4}, {$push: {x: {$each: [{a: 2}], $slice: -2, $sort: {a: -1}}}});
  assert.eq([{a: 2}, {a: 1}], t.findOne({_id: 4}).x);
  
  // $sort over only a portion of the array's elements objects and #slice kicking in
  // using values of both the base doc and of the $each clause.
  t.save({_id: 5, x: [{a: 1, b: 2}, {a: 3, b: 1}]});
  t.update({_id: 5}, {$push: {x: {$each: [{a: 2, b: 3}], $slice: -2, $sort: {b: 1}}}});
  assert.eq([{a: 1, b: 2}, {a: 2, b: 3}], t.findOne({_id: 5}).x);
  
  // $sort over an array of nested objects and $slice too large to kick in.
  t.save({_id: 6, x: [{a: {b: 2}}, {a: {b: 1}}]});
  t.update({_id: 6}, {$push: {x: {$each: [{a: {b: 3}}], $slice: -5, $sort: {'a.b': 1}}}});
  assert.eq([{a: {b: 1}}, {a: {b: 2}}, {a: {b: 3}}], t.findOne({_id: 6}).x);
  
  // $sort over an array of nested objects and $slice kicking in using values of both the
  // base doc and of the $each clause.
  t.save({_id: 7, x: [{a: {b: 2}}, {a: {b: 1}}]});
  t.update({_id: 7}, {$push: {x: {$each: [{a: {b: 3}}], $slice: -2, $sort: {'a.b': 1}}}});
  assert.eq([{a: {b: 2}}, {a: {b: 3}}], t.findOne({_id: 7}).x);
  
  //
  // Invalid Cases
  //
  
  // $push with $sort should not push a "$sort" field
  var doc8 = {_id: 8, x: [{a: 1}, {a: 2}]};
  t.save(doc8);
  var res = t.update({_id: 8}, {$push: {x: {$sort: {a: -1}}}});
  assert.writeErrorWithCode(res, ErrorCodes.DollarPrefixedFieldName);
  assert.docEq(t.findOne({_id: 8}), doc8);  // ensure doc was not changed
  
  t.save({_id: 100, x: [{a: 1}]});
  
  // Elements of the $each vector can be integers. In here, '2' is a valid $each.
  assert.writeOK(t.update({_id: 100}, {$push: {x: {$each: [2], $slice: -2, $sort: {a: 1}}}}));
  
  // For the same reason as above, '1' is an valid $each element.
  assert.writeOK(t.update({_id: 100}, {$push: {x: {$each: [{a: 2}, 1], $slice: -2, $sort: {a: 1}}}}));
  
  // The sort key pattern cannot be empty.
  assert.writeErrorWithCode(
      t.update({_id: 100}, {$push: {x: {$each: [{a: 2}], $slice: -2, $sort: {}}}}),
      ErrorCodes.BadValue);
  
  // Support positive $slice's (ie, trimming from the array's front).
  assert.writeOK(t.update({_id: 100}, {$push: {x: {$each: [{a: 2}], $slice: 2, $sort: {a: 1}}}}));
  
  // A $slice cannot be a fractional value.
  assert.writeErrorWithCode(
      t.update({_id: 100}, {$push: {x: {$each: [{a: 2}], $slice: -2.1, $sort: {a: 1}}}}),
      ErrorCodes.BadValue);
  
  // The sort key pattern's value must be either 1 or -1. In here, {a:-2} is an invalid value.
  assert.writeErrorWithCode(
      t.update({_id: 100}, {$push: {x: {$each: [{a: 2}], $slice: -2, $sort: {a: -2}}}}),
      ErrorCodes.BadValue);
  
  // Support sorting array alements that are not documents.
  assert.writeOK(t.update({_id: 100}, {$push: {x: {$each: [{a: 2}], $slice: -2, $sort: 1}}}));
  
  // The key pattern 'a.' is an invalid value for $sort.
  assert.writeErrorWithCode(
      t.update({_id: 100}, {$push: {x: {$each: [{a: 2}], $slice: -2, $sort: {'a.': 1}}}}),
      ErrorCodes.BadValue);
  
  // An empty key pattern is not a valid $sort value.
  assert.writeErrorWithCode(
      t.update({_id: 100}, {$push: {x: {$each: [{a: 2}], $slice: -2, $sort: {'': 1}}}}),
      ErrorCodes.BadValue);
  
  // If a $slice is used, the only other $sort clause that's accepted is $sort. In here, $xxx
  // is not a valid clause.
  assert.writeErrorWithCode(
      t.update({_id: 100}, {$push: {x: {$each: [{a: 2}], $slice: -2, $xxx: {s: 1}}}}),
      ErrorCodes.BadValue);
  
  t.remove({});
  
  // Existing values are validated in the array do not have to be objects during a $sort with $each.
  t.save({_id: 100, x: [1, "foo"]});
  assert.writeOK(t.update({_id: 100}, {$push: {x: {$each: [{a: 2}], $slice: -2, $sort: {a: 1}}}}));
  