Fix #1079 - Polymorphic hasMany inverse relation (#1296)

This fixes the polymorphic hasMany inverse relation
not working as expected in include filters.

README.md

@@ -18,5 +18,3 @@ Also install the appropriated connector, for example for mongodb:
     npm install loopback-connector-mongodb
 
 See [StrongLoop Documentation](http://docs.strongloop.com/) for more information.
-
-

lib/include.js

@@ -317,10 +317,14 @@ Inclusion.include = function(objects, include, options, cb) {
         inq: uniq(sourceIds),
       };
       if (polymorphic) {
+        var throughModel = polymorphic.invert ?
+          relation.modelTo :
+          relation.modelFrom;
+
         //handle polymorphic hasMany (reverse) in which case we need to filter
         //by discriminator to filter other types
         throughFilter.where[polymorphic.discriminator] =
-          relation.modelFrom.definition.name;
+            throughModel.definition.name;
       }
       /**
        * 1st DB Call of 2 step process. Get through model objects first

test/relations.test.js

@@ -5609,4 +5609,32 @@ describe('relations', function() {
       }).should.throw('Invalid relation name: trigger');
     });
   });
+
+  describe('polymorphic hasMany', function() {
+    before(function(done) {
+      Picture = db.define('Picture', {name: String});
+      Author = db.define('Author', {name: String});
+      PictureLink = db.define('PictureLink', {});
+
+      Author.hasMany(Picture, {through: PictureLink, polymorphic: 'imageable', invert: true});
+      Picture.hasMany(Author, {through: PictureLink, polymorphic: 'imageable'});
+
+      db.automigrate(['Picture', 'Author', 'PictureLink'], done);
+    });
+
+    it('should properly query through an inverted relationship', function(done) {
+      Author.create({name: 'Steve'}, function(err, author) {
+        if (err) { return done(err); }
+        author.pictures.create({name: 'Steve pic 1'}, function(err, pic) {
+          if (err) { return done(err); }
+          Author.findOne({include: 'pictures'}, function(err, author) {
+            if (err) { return done(err); }
+            author.pictures().length.should.eql(1);
+            author.pictures()[0].name.should.eql('Steve pic 1');
+            done();
+          });
+        });
+      });
+    });
+  });
 });