fix(model/findOrBuild): handle includes (#8938)

lib/model.js

@@ -2058,7 +2058,7 @@ class Model {
           values = Utils.defaults(values, options.where);
         }
 
-        instance = this.build(values);
+        instance = this.build(values, options);
 
         return Promise.resolve([instance, true]);
       }

test/integration/model/findOrBuild.test.js

+'use strict';
+
+const chai = require('chai'),
+  expect = chai.expect,
+  Support = require(__dirname + '/../support'),
+  DataTypes = require(__dirname + '/../../../lib/data-types');
+
+describe(Support.getTestDialectTeaser('Model'), () => {
+  beforeEach(function() {
+    this.User = this.sequelize.define('User', {
+      username: DataTypes.STRING,
+      age: DataTypes.INTEGER
+    });
+    this.Project = this.sequelize.define('Project', {
+      name: DataTypes.STRING
+    });
+
+    this.User.hasMany(this.Project);
+    this.Project.belongsTo(this.User);
+
+    return this.sequelize.sync({force: true});
+  });
+
+
+  describe('findOrBuild', () => {
+    it('initialize with includes', function() {
+      return this.User.bulkCreate([
+        { username: 'Mello', age: 10 },
+        { username: 'Mello', age: 20 }
+      ], { returning: true }).spread((user1, user2) => {
+        return this.Project.create({
+          name: 'Investigate'
+        }).then(project => user2.setProjects([project]));
+      }).then(() => {
+        return this.User.findOrBuild({
+          defaults: {
+            username: 'Mello',
+            age: 10
+          },
+          where: {
+            age: 20
+          },
+          include: [{
+            model: this.Project
+          }]
+        });
+      }).spread((user, created) => {
+        expect(created).to.be.false;
+        expect(user.get('id')).to.be.ok;
+        expect(user.get('username')).to.equal('Mello');
+        expect(user.get('age')).to.equal(20);
+
+        expect(user.Projects).to.have.length(1);
+        expect(user.Projects[0].get('name')).to.equal('Investigate');
+      });
+    });
+  });
+});