Can use with

lib/model.js

@@ -266,11 +266,19 @@ lastStepModifierFunctions.$addToSet = function (obj, field, value) {
 
   if (!util.isArray(obj[field])) { throw "Can't $addToSet an element on non-array values"; }
 
-  obj[field].forEach(function (v) {
+  if (value !== null && typeof value === 'object' && value.$each) {
-    if (compareThings(v, value) === 0) { addToSet = false; }
+    if (Object.keys(value).length > 1) { throw "Can't use another field in conjunction with $each"; }
-  });
+    if (!util.isArray(value.$each)) { throw "$each requires an array value"; }
 
-  if (addToSet) { obj[field].push(value); }
+    value.$each.forEach(function (v) {
+      lastStepModifierFunctions.$addToSet(obj, field, v);
+    });
+  } else {
+    obj[field].forEach(function (v) {
+      if (compareThings(v, value) === 0) { addToSet = false; }
+    });
+    if (addToSet) { obj[field].push(value); }
+  }
 };
 
 

test/model.test.js

@@ -438,6 +438,22 @@ describe('Model', function () {
         assert.deepEqual(modified, { arr: [{ b: 2 }] });
       });
 
+      it('Can use the $each modifier to add multiple values to a set at once', function () {
+        var obj = { arr: ['hello'] }
+          , modified;
+
+        modified = model.modify(obj, { $addToSet: { arr: { $each: ['world', 'earth', 'hello', 'earth'] } } });
+        assert.deepEqual(modified, { arr: ['hello', 'world', 'earth'] });
+
+        (function () {
+          modified = model.modify(obj, { $addToSet: { arr: { $each: 45 } } });
+        }).should.throw();
+
+        (function () {
+          modified = model.modify(obj, { $addToSet: { arr: { $each: ['world'], unauthorized: true } } });
+        }).should.throw();
+      });
+
     });   // End of '$addToSet modifier'
 
     describe('$pop modifier', function () {