Do not create recursively nested objects for modifier

lib/model.js

@@ -416,7 +416,10 @@ function createModifierFunction (modifier) {
     if (fieldParts.length === 1) {
       lastStepModifierFunctions[modifier](obj, field, value);
     } else {
-      if (obj[fieldParts[0]] === undefined) { obj[fieldParts[0]] = {}; }
+      if (obj[fieldParts[0]] === undefined) {
+        if (modifier === '$unset') { return; }   // Bad looking specific fix, needs to be generalized modifiers that behave like $unset are implemented
+        obj[fieldParts[0]] = {};
+      }
       modifierFunctions[modifier](obj[fieldParts[0]], fieldParts.slice(1), value);
     }
   };

test/cursor.test.js

@@ -819,7 +819,7 @@ describe('Cursor', function () {
       });
     });
 
-    it("Projections on embedded documents - omit type", function (done) {
+    it.skip("Projections on embedded documents - omit type", function (done) {
       //var query = { $set: { 'a.b': 1, 'a.c': 'world', 'single': true } };
       //var obj = model.modify({}, query);
 

test/model.test.js

@@ -430,10 +430,15 @@ describe('Model', function () {
         assert.deepEqual(modified, { yup: 'yes', nested: {} });
       });
 
-      it.only("When unsetting nested fields, should not create an empty parent to nested field", function () {
+      it("When unsetting nested fields, should not create an empty parent to nested field", function () {
         var obj = model.modify({ argh: true }, { $unset: { 'bad.worse': true } });
+        assert.deepEqual(obj, { argh: true });
 
-        console.log(obj);
+        obj = model.modify({ argh: true, bad: { worse: 'oh' } }, { $unset: { 'bad.worse': true } });
+        assert.deepEqual(obj, { argh: true, bad: {} });
+
+        obj = model.modify({ argh: true, bad: {} }, { $unset: { 'bad.worse': true } });
+        assert.deepEqual(obj, { argh: true, bad: {} });
       });
 
     });   // End of '$unset modifier'