populate; record populated paths from query builder

lib/document.js

@@ -268,19 +268,26 @@ Document.prototype.populate = function populate () {
  * @api private
  */
 
-Document.prototype.init = function (doc, query, fn) {
-  // backwards compat. remove in 4.x
-  if ('function' == typeof query) {
-    fn = query;
-    query = null;
+Document.prototype.init = function (doc, opts, fn) {
+  if ('function' == typeof opts) {
+    fn = opts;
+    opts = null;
   }
-  // end backwards compat
 
   this.isNew = false;
 
   init(this, doc, this._doc);
   this._storeShard();
 
+  // handle docs with populated paths
+  if (opts && opts.populated && opts.populated.length) {
+    var id = this.id;
+    for (var i = 0; i < opts.populated.length; ++i) {
+      var item = opts.populated[i];
+      this.populated(item.path, item._docs[id]);
+    }
+  }
+
   this.emit('init', this);
   if (fn) fn(null);
   return this;

lib/internal.js

@@ -20,6 +20,7 @@ function InternalCache () {
   this.getters = {};
   this._id = undefined;
   this.populate = undefined;
+  this.populated = undefined;
   this.scope = undefined;
   this.activePaths = new ActiveRoster;
 }

lib/model.js

@@ -1636,6 +1636,10 @@ function populate (model, docs, options, cb) {
       ret = utils.getValue(path, doc);
     }
 
+    options._docs[doc._id] = Array.isArray(ret)
+      ? ret.slice()
+      : ret;
+
     if (isDocument) {
       // cache original populated _ids
       doc.populated(path, Array.isArray(ret) ? ret.slice() : ret);

lib/query.js

@@ -61,7 +61,10 @@ Query.prototype.setOptions = function (options, overwrite) {
   // overwrite is internal use only
   if (overwrite) {
     options = this.options = options || {};
-    this.safe = options.safe
+    this.safe = options.safe;
+    if ('populate' in options) {
+      this.populate(this.options.populate);
+    }
     return this;
   }
 
@@ -89,6 +92,7 @@ Query.prototype.setOptions = function (options, overwrite) {
       this.options[method] = options[method];
     }
   }
+
   return this;
 }
 
@@ -1523,15 +1527,15 @@ Query.prototype.execFind = function (callback) {
     if (!self.options.populate) {
       return true === options.lean
         ? promise.complete(docs)
-        : completeMany(model, docs, fields, self, promise);
+        : completeMany(model, docs, fields, self, null, promise);
     }
 
     var pop = utils.object.vals(self.options.populate);
     model.populate(docs, pop, function (err, docs) {
       if (err) return promise.error(err);
       return true === options.lean
         ? promise.complete(docs)
-        : completeMany(model, docs, fields, self, promise);
+        : completeMany(model, docs, fields, self, pop, promise);
     });
   }
 
@@ -1545,18 +1549,22 @@ Query.prototype.execFind = function (callback) {
  * @param {Array} docs
  * @param {Object} fields
  * @param {Query} self
+ * @param {Array} [pop] array of paths used in population
  * @param {Promise} promise
  */
 
-function completeMany (model, docs, fields, self, promise) {
+function completeMany (model, docs, fields, self, pop, promise) {
   var arr = [];
   var count = docs.length;
   var len = count;
   var i = 0;
+  var opts = pop ?
+    { populated: pop }
+    : undefined;
 
   for (; i < len; ++i) {
     arr[i] = new model(undefined, fields, true);
-    arr[i].init(docs[i], function (err) {
+    arr[i].init(docs[i], opts, function (err) {
       if (err) return promise.error(err);
       --count || promise.complete(arr);
     });
@@ -1618,15 +1626,15 @@ Query.prototype.findOne = function (callback) {
     if (!self.options.populate) {
       return true === options.lean
         ? promise.complete(doc)
-        : completeOne(model, doc, fields, self, promise);
+        : completeOne(model, doc, fields, self, null, promise);
     }
 
     var pop = utils.object.vals(self.options.populate);
     model.populate(doc, pop, function (err, doc) {
       if (err) return promise.error(err);
       return true === options.lean
         ? promise.complete(doc)
-        : completeOne(model, doc, fields, self, promise);
+        : completeOne(model, doc, fields, self, pop, promise);
     })
   }));
 
@@ -1640,12 +1648,17 @@ Query.prototype.findOne = function (callback) {
  * @param {Document} doc
  * @param {Object} fields
  * @param {Query} self
+ * @param {Array} [pop] array of paths used in population
  * @param {Promise} promise
  */
 
-function completeOne (model, doc, fields, self, promise) {
+function completeOne (model, doc, fields, self, pop, promise) {
+  var opts = pop ?
+    { populated: pop }
+    : undefined;
+
   var casted = new model(undefined, fields, true);
-  casted.init(doc, function (err) {
+  casted.init(doc, opts, function (err) {
     if (err) return promise.error(err);
     promise.complete(casted);
   });
@@ -2274,7 +2287,7 @@ Query.prototype._findAndModify = function (type, callback) {
     }
 
     var casted = new model(undefined, fields, true);
-    casted.init(doc, self, function (err) {
+    casted.init(doc, function (err) {
       if (err) return promise.error(err);
       promise.complete(casted);
     });
@@ -2323,7 +2336,7 @@ Query.prototype.populate = function populate () {
   var res = utils.populate.apply(null, arguments);
   var opts = this.options;
 
-  if (!opts.populate) {
+  if (!utils.isObject(opts.populate)) {
     opts.populate = {};
   }
 

lib/querystream.js

@@ -212,7 +212,7 @@ QueryStream.prototype._onNextObject = function _onNextObject (err, doc) {
   var instance = new this.query.model(undefined, this._fields, true);
 
   var self = this;
-  instance.init(doc, this.query, function (err) {
+  instance.init(doc, function (err) {
     if (err) return self.destroy(err);
     self.emit('data', instance);
 

lib/utils.js

@@ -488,6 +488,7 @@ function PopulateOptions (path, select, match, options, model) {
   this.select = select;
   this.options = options;
   this.model = model;
+  this._docs = {};
 }
 
 // make it compatible with utils.clone

test/model.populate.test.js

@@ -60,7 +60,7 @@ mongoose.model('RefAlternateUser', User);
  * Tests.
  */
 
-describe('model: ref:', function(){
+describe('model: populate:', function(){
   it('populating a single ref', function(done){
     var db = start()
       , BlogPost = db.model('RefBlogPost', posts)
@@ -1840,6 +1840,7 @@ describe('model: ref:', function(){
         });
       })
     })
+
   })
 
   describe('populating combined with lean (gh-1260)', function(){
@@ -1923,4 +1924,86 @@ describe('model: ref:', function(){
       });
     })
   })
+
+  describe('records paths and _ids used in population', function(){
+    var db;
+    var B;
+    var U;
+    var u1, u2;
+    var b1, b2
+
+    before(function(done){
+      db = start()
+      B = db.model('RefBlogPost', posts + random())
+      U = db.model('RefUser', users + random());
+
+      U.create({
+          name  : 'Fan 1'
+        , email : 'fan1@learnboost.com'
+      }, {
+          name  : 'Fan 2'
+        , email : 'fan2@learnboost.com'
+      }, function (err, fan1, fan2) {
+        assert.ifError(err);
+        u1 = fan1;
+        u2 = fan2;
+
+        B.create({
+            title : 'Woot'
+          , fans  : [fan1, fan2]
+          , _creator: fan1
+        }, {
+            title : 'Woot2'
+          , fans  : [fan2, fan1]
+          , _creator: fan2
+        }, function (err, post1, post2) {
+          assert.ifError(err);
+          b1 = post1;
+          b2 = post2;
+          done();
+        });
+      });
+    })
+
+    after(function(){
+      db.close()
+    })
+
+    it('with findOne', function(done){
+      B.findById(b1).populate('fans _creator').exec(function (err, doc) {
+        assert.ifError(err);
+        assert.ok(Array.isArray(doc.populated('fans')));
+        assert.equal(2, doc.populated('fans').length);
+        assert.equal(doc.populated('fans')[0], String(u1._id));
+        assert.equal(doc.populated('fans')[1], String(u2._id));
+        assert.equal(doc.populated('_creator'), String(u1._id));
+        done();
+      })
+    })
+
+    it('with find', function(done){
+      B.find().populate('fans _creator').exec(function (err, docs) {
+        assert.ifError(err);
+        assert.equal(2, docs.length);
+
+        var doc1 = docs[0];
+        var doc2 = docs[1];
+
+        assert.ok(Array.isArray(doc1.populated('fans')));
+        assert.equal(2, doc1.populated('fans').length);
+        assert.equal(doc1.populated('fans')[0], String(u1._id));
+        assert.equal(doc1.populated('fans')[1], String(u2._id));
+        assert.equal(doc1.populated('_creator'), String(u1._id));
+
+        assert.ok(Array.isArray(doc2.populated('fans')));
+        assert.equal(2, doc2.populated('fans').length);
+        assert.equal(doc2.populated('fans')[0], String(u2._id));
+        assert.equal(doc2.populated('fans')[1], String(u1._id));
+        assert.equal(doc2.populated('_creator'), String(u2._id));
+        done();
+      })
+    })
+  })
+
+
 });

test/query.test.js

@@ -732,6 +732,7 @@ describe('Query', function(){
         , select: undefined
         , model: undefined
         , options: undefined
+        , _docs: {}
       }
       q.populate(o);
       assert.deepEqual(o, q.options.populate['yellow.brick']);
@@ -746,6 +747,7 @@ describe('Query', function(){
         , select: undefined
         , model: undefined
         , options: undefined
+        , _docs: {}
       }
       q.populate(o);
       assert.equal(1, Object.keys(q.options.populate).length);
@@ -766,6 +768,7 @@ describe('Query', function(){
         , select: undefined
         , model: undefined
         , options: undefined
+        , _docs: {}
       }
       assert.equal(2, Object.keys(q.options.populate).length);
       assert.deepEqual(o, q.options.populate['yellow.brick']);
@@ -1258,7 +1261,7 @@ describe('Query', function(){
       q.setOptions({ read: ['s', [{dc:'eu'}]]});
 
       assert.equal(q.options.thing, 'cat');
-      assert.deepEqual(q.options.populate.fans, { path: 'fans', select: undefined, match: undefined, options: undefined, model: undefined });
+      assert.deepEqual(q.options.populate.fans, { path: 'fans', select: undefined, match: undefined, options: undefined, model: undefined, _docs: {} });
       assert.equal(q.options.batchSize, 10);
       assert.equal(q.options.limit, 4);
       assert.equal(q.options.skip, 3);