support Relation object saving (#3074)

* support Parse.Relation object save

* prevent Relation object from being saved in storage

spec/MongoTransform.spec.js

@@ -236,6 +236,19 @@ describe('parseObjectToMongoObjectForCreate', () => {
     done();
   });
 
+  it('removes Relation types', (done) => {
+    var input = {
+      aRelation: { __type: 'Relation', className: 'Stuff' },
+    };
+    var output = transform.parseObjectToMongoObjectForCreate(null, input, {
+      fields: {
+        aRelation: { __type: 'Relation', className: 'Stuff' }, 
+      },
+    });
+    expect(output).toEqual({});
+    done();
+  });
+
   it('writes the old ACL format in addition to rperm and wperm on update', (done) => {
     var input = {
       _rperm: ['*'],
@@ -280,5 +293,19 @@ describe('parseObjectToMongoObjectForCreate', () => {
     expect(output.double).toBe(Number.MAX_VALUE);
     done();
   });
-
+});
+
+describe('transformUpdate', () => {
+  it('removes Relation types', (done) => {
+    var input = {
+      aRelation: { __type: 'Relation', className: 'Stuff' },
+    };
+    var output = transform.transformUpdate(null, input, {
+      fields: {
+        aRelation: { __type: 'Relation', className: 'Stuff' }, 
+      },
+    });
+    expect(output).toEqual({});
+    done();
+  });
 });

spec/ParseRelation.spec.js

@@ -741,4 +741,32 @@ describe('Parse.Relation testing', () => {
       done();
     });
   });
+
+  it('can be saved without error', done => {
+    let obj1 = new Parse.Object('PPAP');
+    obj1.save()
+    .then(() => {
+      let newRelation = obj1.relation('aRelation');
+      newRelation.add(obj1);
+      obj1.save().then(() => {
+        let relation = obj1.get('aRelation');
+        obj1.set('aRelation', relation);
+        obj1.save().then(() => {
+          done();
+        }, error => {
+          fail('failed to save ParseRelation object');
+          fail(error);
+          done();
+        });
+      }, error => {
+        fail('failed to create relation field');
+        fail(error);
+        done();
+      });
+    }, error => {
+      fail('failed to save obj');
+      fail(error);
+      done();
+    });
+  });
 });

spec/Schema.spec.js

@@ -56,6 +56,21 @@ describe('SchemaController', () => {
     });
   });
 
+  it('can validate Relation object', (done) => {
+    config.database.loadSchema().then((schema) => {
+      return schema.validateObject('Stuff', {aRelation: {__type:'Relation',className:'Stuff'}});
+    }).then((schema) => {
+      return schema.validateObject('Stuff', {aRelation: {__type:'Pointer',className:'Stuff'}})
+      .then((schema) => {
+        fail('expected invalidity');
+        done();
+      }, done);
+    }, (err) => {
+      fail(err);
+      done();
+    });
+  });
+
   it('rejects inconsistent types', (done) => {
     config.database.loadSchema().then((schema) => {
       return schema.validateObject('Stuff', {bacon: 7});