Futzing with read preference (#3963)

* allow setting readpreference when using rest api.

* take out partially complete unit test.

* oops. nit

* Include read preference option for find directly from api and adding few more tests

* Adding catch for all tests

* Keep same check for get and find

* Turn read preference case insensitive

* Includes and subqueries read preferences through API

* Fixing bugs regarding changes that were done in master branch during the last year

* Changing behavior to make includeReadPreference and subqueryReadPreference to follow readPreference by default

spec/GridFSBucketStorageAdapter.spec.js

@@ -41,16 +41,12 @@ describe('GridFSBucket and GridStore interop', () => {
     expect(gfsResult.toString('utf8')).toBe(twoMegabytesFile);
   });
 
-  it(
-    'properly deletes a file from GridFS',
-    async () => {
+  it('properly deletes a file from GridFS', async () => {
     const gfsAdapter = new GridFSBucketAdapter(databaseURI);
     await gfsAdapter.createFile('myFileName', 'a simple file');
     await gfsAdapter.deleteFile('myFileName');
     await expectMissingFile(gfsAdapter, 'myFileName');
-    },
-    1000000
-  );
+  }, 1000000);
 
   it('properly overrides files', async () => {
     const gfsAdapter = new GridFSBucketAdapter(databaseURI);

spec/ReadPreferenceOption.spec.js

@@ -108,7 +108,9 @@ describe_only_db('mongo')('Read preference option', () => {
       const query = new Parse.Query('MyObject');
       query.equalTo('boolKey', false);
 
-      query.find().then(results => {
+      query
+        .find()
+        .then(results => {
           expect(results.length).toBe(1);
           expect(results[0].get('boolKey')).toBe(false);
 
@@ -124,8 +126,50 @@ describe_only_db('mongo')('Read preference option', () => {
           expect(myObjectReadPreference).toEqual(ReadPreference.SECONDARY);
 
           done();
+        })
+        .catch(done.fail);
     });
   });
+
+  it('should check read preference as case insensitive', done => {
+    const databaseAdapter = Config.get(Parse.applicationId).database.adapter;
+
+    const obj0 = new Parse.Object('MyObject');
+    obj0.set('boolKey', false);
+    const obj1 = new Parse.Object('MyObject');
+    obj1.set('boolKey', true);
+
+    Parse.Object.saveAll([obj0, obj1]).then(() => {
+      spyOn(databaseAdapter.database.serverConfig, 'cursor').and.callThrough();
+
+      Parse.Cloud.beforeFind('MyObject', req => {
+        req.readPreference = 'sEcOnDarY';
+      });
+
+      const query = new Parse.Query('MyObject');
+      query.equalTo('boolKey', false);
+
+      query
+        .find()
+        .then(results => {
+          expect(results.length).toBe(1);
+          expect(results[0].get('boolKey')).toBe(false);
+
+          let myObjectReadPreference = null;
+          databaseAdapter.database.serverConfig.cursor.calls
+            .all()
+            .forEach(call => {
+              if (call.args[0].indexOf('MyObject') >= 0) {
+                myObjectReadPreference = call.args[2].readPreference.preference;
+              }
+            });
+
+          expect(myObjectReadPreference).toEqual(ReadPreference.SECONDARY);
+
+          done();
+        })
+        .catch(done.fail);
+    });
   });
 
   it('should change read preference in the beforeFind trigger even changing query', done => {
@@ -147,7 +191,9 @@ describe_only_db('mongo')('Read preference option', () => {
       const query = new Parse.Query('MyObject');
       query.equalTo('boolKey', false);
 
-      query.find().then(results => {
+      query
+        .find()
+        .then(results => {
           expect(results.length).toBe(1);
           expect(results[0].get('boolKey')).toBe(true);
 
@@ -163,7 +209,8 @@ describe_only_db('mongo')('Read preference option', () => {
           expect(myObjectReadPreference).toEqual(ReadPreference.SECONDARY);
 
           done();
-      });
+        })
+        .catch(done.fail);
     });
   });
 
@@ -189,7 +236,9 @@ describe_only_db('mongo')('Read preference option', () => {
       const query = new Parse.Query('MyObject');
       query.equalTo('boolKey', false);
 
-      query.find().then(results => {
+      query
+        .find()
+        .then(results => {
           expect(results.length).toBe(1);
           expect(results[0].get('boolKey')).toBe(true);
 
@@ -205,7 +254,8 @@ describe_only_db('mongo')('Read preference option', () => {
           expect(myObjectReadPreference).toEqual(ReadPreference.SECONDARY);
 
           done();
-      });
+        })
+        .catch(done.fail);
     });
   });
 
@@ -231,7 +281,9 @@ describe_only_db('mongo')('Read preference option', () => {
       const query = new Parse.Query('MyObject');
       query.equalTo('boolKey', false);
 
-      query.find().then(results => {
+      query
+        .find()
+        .then(results => {
           expect(results.length).toBe(1);
           expect(results[0].get('boolKey')).toBe(true);
 
@@ -247,7 +299,8 @@ describe_only_db('mongo')('Read preference option', () => {
           expect(myObjectReadPreference).toEqual(ReadPreference.SECONDARY);
 
           done();
-      });
+        })
+        .catch(done.fail);
     });
   });
 
@@ -269,7 +322,9 @@ describe_only_db('mongo')('Read preference option', () => {
       const query = new Parse.Query('MyObject');
       query.equalTo('boolKey', false);
 
-      query.find().then(results => {
+      query
+        .find()
+        .then(results => {
           expect(results.length).toBe(1);
           expect(results[0].get('boolKey')).toBe(false);
 
@@ -287,7 +342,8 @@ describe_only_db('mongo')('Read preference option', () => {
           );
 
           done();
-      });
+        })
+        .catch(done.fail);
     });
   });
 
@@ -309,7 +365,9 @@ describe_only_db('mongo')('Read preference option', () => {
       const query = new Parse.Query('MyObject');
       query.equalTo('boolKey', false);
 
-      query.find().then(results => {
+      query
+        .find()
+        .then(results => {
           expect(results.length).toBe(1);
           expect(results[0].get('boolKey')).toBe(false);
 
@@ -327,7 +385,8 @@ describe_only_db('mongo')('Read preference option', () => {
           );
 
           done();
-      });
+        })
+        .catch(done.fail);
     });
   });
 
@@ -349,7 +408,9 @@ describe_only_db('mongo')('Read preference option', () => {
       const query = new Parse.Query('MyObject');
       query.equalTo('boolKey', false);
 
-      query.find().then(results => {
+      query
+        .find()
+        .then(results => {
           expect(results.length).toBe(1);
           expect(results[0].get('boolKey')).toBe(false);
 
@@ -365,7 +426,8 @@ describe_only_db('mongo')('Read preference option', () => {
           expect(myObjectReadPreference).toEqual(ReadPreference.NEAREST);
 
           done();
-      });
+        })
+        .catch(done.fail);
     });
   });
 
@@ -386,7 +448,9 @@ describe_only_db('mongo')('Read preference option', () => {
 
       const query = new Parse.Query('MyObject');
 
-      query.get(obj0.id).then(result => {
+      query
+        .get(obj0.id)
+        .then(result => {
           expect(result.get('boolKey')).toBe(false);
 
           let myObjectReadPreference = null;
@@ -401,7 +465,8 @@ describe_only_db('mongo')('Read preference option', () => {
           expect(myObjectReadPreference).toEqual(ReadPreference.SECONDARY);
 
           done();
-      });
+        })
+        .catch(done.fail);
     });
   });
 
@@ -428,7 +493,8 @@ describe_only_db('mongo')('Read preference option', () => {
           'X-Parse-REST-API-Key': 'rest',
         },
         json: true,
-      }).then(response => {
+      })
+        .then(response => {
           const body = response.data;
           expect(body.boolKey).toBe(false);
 
@@ -444,8 +510,233 @@ describe_only_db('mongo')('Read preference option', () => {
           expect(myObjectReadPreference).toEqual(ReadPreference.SECONDARY);
 
           done();
+        })
+        .catch(done.fail);
     });
   });
+
+  it('should change read preference for GET directly from API', done => {
+    const databaseAdapter = Config.get(Parse.applicationId).database.adapter;
+
+    const obj0 = new Parse.Object('MyObject');
+    obj0.set('boolKey', false);
+    const obj1 = new Parse.Object('MyObject');
+    obj1.set('boolKey', true);
+
+    Parse.Object.saveAll([obj0, obj1]).then(() => {
+      spyOn(databaseAdapter.database.serverConfig, 'cursor').and.callThrough();
+
+      request({
+        method: 'GET',
+        url:
+          'http://localhost:8378/1/classes/MyObject/' +
+          obj0.id +
+          '?readPreference=SECONDARY',
+        headers: {
+          'X-Parse-Application-Id': 'test',
+          'X-Parse-REST-API-Key': 'rest',
+        },
+        json: true,
+      })
+        .then(response => {
+          expect(response.data.boolKey).toBe(false);
+
+          let myObjectReadPreference = null;
+          databaseAdapter.database.serverConfig.cursor.calls
+            .all()
+            .forEach(call => {
+              if (call.args[0].indexOf('MyObject') >= 0) {
+                myObjectReadPreference = call.args[2].readPreference.preference;
+              }
+            });
+
+          expect(myObjectReadPreference).toEqual(ReadPreference.SECONDARY);
+
+          done();
+        })
+        .catch(done.fail);
+    });
+  });
+
+  it('should change read preference for GET using API through the beforeFind overriding API option', done => {
+    const databaseAdapter = Config.get(Parse.applicationId).database.adapter;
+
+    const obj0 = new Parse.Object('MyObject');
+    obj0.set('boolKey', false);
+    const obj1 = new Parse.Object('MyObject');
+    obj1.set('boolKey', true);
+
+    Parse.Object.saveAll([obj0, obj1]).then(() => {
+      spyOn(databaseAdapter.database.serverConfig, 'cursor').and.callThrough();
+
+      Parse.Cloud.beforeFind('MyObject', req => {
+        req.readPreference = 'SECONDARY_PREFERRED';
+      });
+
+      request({
+        method: 'GET',
+        url:
+          'http://localhost:8378/1/classes/MyObject/' +
+          obj0.id +
+          '?readPreference=SECONDARY',
+        headers: {
+          'X-Parse-Application-Id': 'test',
+          'X-Parse-REST-API-Key': 'rest',
+        },
+        json: true,
+      })
+        .then(response => {
+          expect(response.data.boolKey).toBe(false);
+
+          let myObjectReadPreference = null;
+          databaseAdapter.database.serverConfig.cursor.calls
+            .all()
+            .forEach(call => {
+              if (call.args[0].indexOf('MyObject') >= 0) {
+                myObjectReadPreference = call.args[2].readPreference.preference;
+              }
+            });
+
+          expect(myObjectReadPreference).toEqual(
+            ReadPreference.SECONDARY_PREFERRED
+          );
+
+          done();
+        })
+        .catch(done.fail);
+    });
+  });
+
+  it('should change read preference for FIND using API through beforeFind trigger', done => {
+    const databaseAdapter = Config.get(Parse.applicationId).database.adapter;
+
+    const obj0 = new Parse.Object('MyObject');
+    obj0.set('boolKey', false);
+    const obj1 = new Parse.Object('MyObject');
+    obj1.set('boolKey', true);
+
+    Parse.Object.saveAll([obj0, obj1]).then(() => {
+      spyOn(databaseAdapter.database.serverConfig, 'cursor').and.callThrough();
+
+      Parse.Cloud.beforeFind('MyObject', req => {
+        req.readPreference = 'SECONDARY';
+      });
+
+      request({
+        method: 'GET',
+        url: 'http://localhost:8378/1/classes/MyObject/',
+        headers: {
+          'X-Parse-Application-Id': 'test',
+          'X-Parse-REST-API-Key': 'rest',
+        },
+        json: true,
+      })
+        .then(response => {
+          expect(response.data.results.length).toEqual(2);
+
+          let myObjectReadPreference = null;
+          databaseAdapter.database.serverConfig.cursor.calls
+            .all()
+            .forEach(call => {
+              if (call.args[0].indexOf('MyObject') >= 0) {
+                myObjectReadPreference = call.args[2].readPreference.preference;
+              }
+            });
+
+          expect(myObjectReadPreference).toEqual(ReadPreference.SECONDARY);
+
+          done();
+        })
+        .catch(done.fail);
+    });
+  });
+
+  it('should change read preference for FIND directly from API', done => {
+    const databaseAdapter = Config.get(Parse.applicationId).database.adapter;
+
+    const obj0 = new Parse.Object('MyObject');
+    obj0.set('boolKey', false);
+    const obj1 = new Parse.Object('MyObject');
+    obj1.set('boolKey', true);
+
+    Parse.Object.saveAll([obj0, obj1]).then(() => {
+      spyOn(databaseAdapter.database.serverConfig, 'cursor').and.callThrough();
+
+      request({
+        method: 'GET',
+        url:
+          'http://localhost:8378/1/classes/MyObject?readPreference=SECONDARY',
+        headers: {
+          'X-Parse-Application-Id': 'test',
+          'X-Parse-REST-API-Key': 'rest',
+        },
+        json: true,
+      })
+        .then(response => {
+          expect(response.data.results.length).toEqual(2);
+
+          let myObjectReadPreference = null;
+          databaseAdapter.database.serverConfig.cursor.calls
+            .all()
+            .forEach(call => {
+              if (call.args[0].indexOf('MyObject') >= 0) {
+                myObjectReadPreference = call.args[2].readPreference.preference;
+              }
+            });
+
+          expect(myObjectReadPreference).toEqual(ReadPreference.SECONDARY);
+
+          done();
+        })
+        .catch(done.fail);
+    });
+  });
+
+  it('should change read preference for FIND using API through the beforeFind overriding API option', done => {
+    const databaseAdapter = Config.get(Parse.applicationId).database.adapter;
+
+    const obj0 = new Parse.Object('MyObject');
+    obj0.set('boolKey', false);
+    const obj1 = new Parse.Object('MyObject');
+    obj1.set('boolKey', true);
+
+    Parse.Object.saveAll([obj0, obj1]).then(() => {
+      spyOn(databaseAdapter.database.serverConfig, 'cursor').and.callThrough();
+
+      Parse.Cloud.beforeFind('MyObject', req => {
+        req.readPreference = 'SECONDARY_PREFERRED';
+      });
+
+      request({
+        method: 'GET',
+        url:
+          'http://localhost:8378/1/classes/MyObject/?readPreference=SECONDARY',
+        headers: {
+          'X-Parse-Application-Id': 'test',
+          'X-Parse-REST-API-Key': 'rest',
+        },
+        json: true,
+      })
+        .then(response => {
+          expect(response.data.results.length).toEqual(2);
+
+          let myObjectReadPreference = null;
+          databaseAdapter.database.serverConfig.cursor.calls
+            .all()
+            .forEach(call => {
+              if (call.args[0].indexOf('MyObject') >= 0) {
+                myObjectReadPreference = call.args[2].readPreference.preference;
+              }
+            });
+
+          expect(myObjectReadPreference).toEqual(
+            ReadPreference.SECONDARY_PREFERRED
+          );
+
+          done();
+        })
+        .catch(done.fail);
+    });
   });
 
   it('should change read preference for count', done => {
@@ -466,7 +757,9 @@ describe_only_db('mongo')('Read preference option', () => {
       const query = new Parse.Query('MyObject');
       query.equalTo('boolKey', false);
 
-      query.count().then(result => {
+      query
+        .count()
+        .then(result => {
           expect(result).toBe(1);
 
           let myObjectReadPreference = null;
@@ -481,11 +774,12 @@ describe_only_db('mongo')('Read preference option', () => {
           expect(myObjectReadPreference).toEqual(ReadPreference.SECONDARY);
 
           done();
-      });
+        })
+        .catch(done.fail);
     });
   });
 
-  it('should find includes in primary by default', done => {
+  it('should find includes in same replica of readPreference by default', done => {
     const databaseAdapter = Config.get(Parse.applicationId).database.adapter;
 
     const obj0 = new Parse.Object('MyObject0');
@@ -509,7 +803,9 @@ describe_only_db('mongo')('Read preference option', () => {
       query.include('myObject1');
       query.include('myObject1.myObject0');
 
-      query.find().then(results => {
+      query
+        .find()
+        .then(results => {
           expect(results.length).toBe(1);
           const firstResult = results[0];
           expect(firstResult.get('boolKey')).toBe(false);
@@ -528,24 +824,26 @@ describe_only_db('mongo')('Read preference option', () => {
             .all()
             .forEach(call => {
               if (call.args[0].indexOf('MyObject0') >= 0) {
-              myObjectReadPreference0 = true;
-              expect(call.args[2].readPreference).toBe(null);
+                myObjectReadPreference0 =
+                  call.args[2].readPreference.preference;
               }
               if (call.args[0].indexOf('MyObject1') >= 0) {
-              myObjectReadPreference1 = true;
-              expect(call.args[2].readPreference).toBe(null);
+                myObjectReadPreference1 =
+                  call.args[2].readPreference.preference;
               }
               if (call.args[0].indexOf('MyObject2') >= 0) {
-              myObjectReadPreference2 = call.args[2].readPreference.preference;
+                myObjectReadPreference2 =
+                  call.args[2].readPreference.preference;
               }
             });
 
-        expect(myObjectReadPreference0).toBe(true);
-        expect(myObjectReadPreference1).toBe(true);
+          expect(myObjectReadPreference0).toEqual(ReadPreference.SECONDARY);
+          expect(myObjectReadPreference1).toEqual(ReadPreference.SECONDARY);
           expect(myObjectReadPreference2).toEqual(ReadPreference.SECONDARY);
 
           done();
-      });
+        })
+        .catch(done.fail);
     });
   });
 
@@ -574,7 +872,9 @@ describe_only_db('mongo')('Read preference option', () => {
       query.include('myObject1');
       query.include('myObject1.myObject0');
 
-      query.find().then(results => {
+      query
+        .find()
+        .then(results => {
           expect(results.length).toBe(1);
           const firstResult = results[0];
           expect(firstResult.get('boolKey')).toBe(false);
@@ -593,13 +893,16 @@ describe_only_db('mongo')('Read preference option', () => {
             .all()
             .forEach(call => {
               if (call.args[0].indexOf('MyObject0') >= 0) {
-              myObjectReadPreference0 = call.args[2].readPreference.preference;
+                myObjectReadPreference0 =
+                  call.args[2].readPreference.preference;
               }
               if (call.args[0].indexOf('MyObject1') >= 0) {
-              myObjectReadPreference1 = call.args[2].readPreference.preference;
+                myObjectReadPreference1 =
+                  call.args[2].readPreference.preference;
               }
               if (call.args[0].indexOf('MyObject2') >= 0) {
-              myObjectReadPreference2 = call.args[2].readPreference.preference;
+                myObjectReadPreference2 =
+                  call.args[2].readPreference.preference;
               }
             });
 
@@ -610,11 +913,147 @@ describe_only_db('mongo')('Read preference option', () => {
           );
 
           done();
-      });
+        })
+        .catch(done.fail);
     });
   });
 
-  it('should find subqueries in primary by default', done => {
+  it('should change includes read preference when finding through API', done => {
+    const databaseAdapter = Config.get(Parse.applicationId).database.adapter;
+
+    const obj0 = new Parse.Object('MyObject0');
+    obj0.set('boolKey', false);
+    const obj1 = new Parse.Object('MyObject1');
+    obj1.set('boolKey', true);
+    obj1.set('myObject0', obj0);
+    const obj2 = new Parse.Object('MyObject2');
+    obj2.set('boolKey', false);
+    obj2.set('myObject1', obj1);
+
+    Parse.Object.saveAll([obj0, obj1, obj2]).then(() => {
+      spyOn(databaseAdapter.database.serverConfig, 'cursor').and.callThrough();
+
+      request({
+        method: 'GET',
+        url:
+          'http://localhost:8378/1/classes/MyObject2/' +
+          obj2.id +
+          '?include=' +
+          JSON.stringify(['myObject1', 'myObject1.myObject0']) +
+          '&readPreference=SECONDARY_PREFERRED&includeReadPreference=SECONDARY',
+        headers: {
+          'X-Parse-Application-Id': 'test',
+          'X-Parse-REST-API-Key': 'rest',
+        },
+        json: true,
+      })
+        .then(response => {
+          const firstResult = response.data;
+          expect(firstResult.boolKey).toBe(false);
+          expect(firstResult.myObject1.boolKey).toBe(true);
+          expect(firstResult.myObject1.myObject0.boolKey).toBe(false);
+
+          let myObjectReadPreference0 = null;
+          let myObjectReadPreference1 = null;
+          let myObjectReadPreference2 = null;
+          databaseAdapter.database.serverConfig.cursor.calls
+            .all()
+            .forEach(call => {
+              if (call.args[0].indexOf('MyObject0') >= 0) {
+                myObjectReadPreference0 =
+                  call.args[2].readPreference.preference;
+              }
+              if (call.args[0].indexOf('MyObject1') >= 0) {
+                myObjectReadPreference1 =
+                  call.args[2].readPreference.preference;
+              }
+              if (call.args[0].indexOf('MyObject2') >= 0) {
+                myObjectReadPreference2 =
+                  call.args[2].readPreference.preference;
+              }
+            });
+
+          expect(myObjectReadPreference0).toEqual(ReadPreference.SECONDARY);
+          expect(myObjectReadPreference1).toEqual(ReadPreference.SECONDARY);
+          expect(myObjectReadPreference2).toEqual(
+            ReadPreference.SECONDARY_PREFERRED
+          );
+
+          done();
+        })
+        .catch(done.fail);
+    });
+  });
+
+  it('should change includes read preference when getting through API', done => {
+    const databaseAdapter = Config.get(Parse.applicationId).database.adapter;
+
+    const obj0 = new Parse.Object('MyObject0');
+    obj0.set('boolKey', false);
+    const obj1 = new Parse.Object('MyObject1');
+    obj1.set('boolKey', true);
+    obj1.set('myObject0', obj0);
+    const obj2 = new Parse.Object('MyObject2');
+    obj2.set('boolKey', false);
+    obj2.set('myObject1', obj1);
+
+    Parse.Object.saveAll([obj0, obj1, obj2]).then(() => {
+      spyOn(databaseAdapter.database.serverConfig, 'cursor').and.callThrough();
+
+      request({
+        method: 'GET',
+        url:
+          'http://localhost:8378/1/classes/MyObject2?where=' +
+          JSON.stringify({ boolKey: false }) +
+          '&include=' +
+          JSON.stringify(['myObject1', 'myObject1.myObject0']) +
+          '&readPreference=SECONDARY_PREFERRED&includeReadPreference=SECONDARY',
+        headers: {
+          'X-Parse-Application-Id': 'test',
+          'X-Parse-REST-API-Key': 'rest',
+        },
+        json: true,
+      })
+        .then(response => {
+          expect(response.data.results.length).toBe(1);
+          const firstResult = response.data.results[0];
+          expect(firstResult.boolKey).toBe(false);
+          expect(firstResult.myObject1.boolKey).toBe(true);
+          expect(firstResult.myObject1.myObject0.boolKey).toBe(false);
+
+          let myObjectReadPreference0 = null;
+          let myObjectReadPreference1 = null;
+          let myObjectReadPreference2 = null;
+          databaseAdapter.database.serverConfig.cursor.calls
+            .all()
+            .forEach(call => {
+              if (call.args[0].indexOf('MyObject0') >= 0) {
+                myObjectReadPreference0 =
+                  call.args[2].readPreference.preference;
+              }
+              if (call.args[0].indexOf('MyObject1') >= 0) {
+                myObjectReadPreference1 =
+                  call.args[2].readPreference.preference;
+              }
+              if (call.args[0].indexOf('MyObject2') >= 0) {
+                myObjectReadPreference2 =
+                  call.args[2].readPreference.preference;
+              }
+            });
+
+          expect(myObjectReadPreference0).toEqual(ReadPreference.SECONDARY);
+          expect(myObjectReadPreference1).toEqual(ReadPreference.SECONDARY);
+          expect(myObjectReadPreference2).toEqual(
+            ReadPreference.SECONDARY_PREFERRED
+          );
+
+          done();
+        })
+        .catch(done.fail);
+    });
+  });
+
+  it('should find subqueries in same replica of readPreference by default', done => {
     const databaseAdapter = Config.get(Parse.applicationId).database.adapter;
 
     const obj0 = new Parse.Object('MyObject0');
@@ -642,7 +1081,9 @@ describe_only_db('mongo')('Read preference option', () => {
       const query2 = new Parse.Query('MyObject2');
       query2.matchesQuery('myObject1', query1);
 
-      query2.find().then(results => {
+      query2
+        .find()
+        .then(results => {
           expect(results.length).toBe(1);
           expect(results[0].get('boolKey')).toBe(false);
 
@@ -653,24 +1094,26 @@ describe_only_db('mongo')('Read preference option', () => {
             .all()
             .forEach(call => {
               if (call.args[0].indexOf('MyObject0') >= 0) {
-              myObjectReadPreference0 = true;
-              expect(call.args[2].readPreference).toBe(null);
+                myObjectReadPreference0 =
+                  call.args[2].readPreference.preference;
               }
               if (call.args[0].indexOf('MyObject1') >= 0) {
-              myObjectReadPreference1 = true;
-              expect(call.args[2].readPreference).toBe(null);
+                myObjectReadPreference1 =
+                  call.args[2].readPreference.preference;
               }
               if (call.args[0].indexOf('MyObject2') >= 0) {
-              myObjectReadPreference2 = call.args[2].readPreference.preference;
+                myObjectReadPreference2 =
+                  call.args[2].readPreference.preference;
               }
             });
 
-        expect(myObjectReadPreference0).toBe(true);
-        expect(myObjectReadPreference1).toBe(true);
+          expect(myObjectReadPreference0).toEqual(ReadPreference.SECONDARY);
+          expect(myObjectReadPreference1).toEqual(ReadPreference.SECONDARY);
           expect(myObjectReadPreference2).toEqual(ReadPreference.SECONDARY);
 
           done();
-      });
+        })
+        .catch(done.fail);
     });
   });
 
@@ -703,7 +1146,9 @@ describe_only_db('mongo')('Read preference option', () => {
       const query2 = new Parse.Query('MyObject2');
       query2.matchesQuery('myObject1', query1);
 
-      query2.find().then(results => {
+      query2
+        .find()
+        .then(results => {
           expect(results.length).toBe(1);
           expect(results[0].get('boolKey')).toBe(false);
 
@@ -714,13 +1159,16 @@ describe_only_db('mongo')('Read preference option', () => {
             .all()
             .forEach(call => {
               if (call.args[0].indexOf('MyObject0') >= 0) {
-              myObjectReadPreference0 = call.args[2].readPreference.preference;
+                myObjectReadPreference0 =
+                  call.args[2].readPreference.preference;
               }
               if (call.args[0].indexOf('MyObject1') >= 0) {
-              myObjectReadPreference1 = call.args[2].readPreference.preference;
+                myObjectReadPreference1 =
+                  call.args[2].readPreference.preference;
               }
               if (call.args[0].indexOf('MyObject2') >= 0) {
-              myObjectReadPreference2 = call.args[2].readPreference.preference;
+                myObjectReadPreference2 =
+                  call.args[2].readPreference.preference;
               }
             });
 
@@ -731,7 +1179,8 @@ describe_only_db('mongo')('Read preference option', () => {
           );
 
           done();
-      });
+        })
+        .catch(done.fail);
     });
   });
 
@@ -764,7 +1213,9 @@ describe_only_db('mongo')('Read preference option', () => {
       const query2 = new Parse.Query('MyObject2');
       query2.doesNotMatchQuery('myObject1', query1);
 
-      query2.find().then(results => {
+      query2
+        .find()
+        .then(results => {
           expect(results.length).toBe(1);
           expect(results[0].get('boolKey')).toBe(false);
 
@@ -775,13 +1226,16 @@ describe_only_db('mongo')('Read preference option', () => {
             .all()
             .forEach(call => {
               if (call.args[0].indexOf('MyObject0') >= 0) {
-              myObjectReadPreference0 = call.args[2].readPreference.preference;
+                myObjectReadPreference0 =
+                  call.args[2].readPreference.preference;
               }
               if (call.args[0].indexOf('MyObject1') >= 0) {
-              myObjectReadPreference1 = call.args[2].readPreference.preference;
+                myObjectReadPreference1 =
+                  call.args[2].readPreference.preference;
               }
               if (call.args[0].indexOf('MyObject2') >= 0) {
-              myObjectReadPreference2 = call.args[2].readPreference.preference;
+                myObjectReadPreference2 =
+                  call.args[2].readPreference.preference;
               }
             });
 
@@ -792,7 +1246,8 @@ describe_only_db('mongo')('Read preference option', () => {
           );
 
           done();
-      });
+        })
+        .catch(done.fail);
     });
   });
 
@@ -826,7 +1281,9 @@ describe_only_db('mongo')('Read preference option', () => {
       query2.matchesKeyInQuery('boolKey', 'boolKey', query0);
       query2.doesNotMatchKeyInQuery('boolKey', 'boolKey', query1);
 
-      query2.find().then(results => {
+      query2
+        .find()
+        .then(results => {
           expect(results.length).toBe(1);
           expect(results[0].get('boolKey')).toBe(false);
 
@@ -837,13 +1294,16 @@ describe_only_db('mongo')('Read preference option', () => {
             .all()
             .forEach(call => {
               if (call.args[0].indexOf('MyObject0') >= 0) {
-              myObjectReadPreference0 = call.args[2].readPreference.preference;
+                myObjectReadPreference0 =
+                  call.args[2].readPreference.preference;
               }
               if (call.args[0].indexOf('MyObject1') >= 0) {
-              myObjectReadPreference1 = call.args[2].readPreference.preference;
+                myObjectReadPreference1 =
+                  call.args[2].readPreference.preference;
               }
               if (call.args[0].indexOf('MyObject2') >= 0) {
-              myObjectReadPreference2 = call.args[2].readPreference.preference;
+                myObjectReadPreference2 =
+                  call.args[2].readPreference.preference;
               }
             });
 
@@ -854,7 +1314,90 @@ describe_only_db('mongo')('Read preference option', () => {
           );
 
           done();
-      });
+        })
+        .catch(done.fail);
+    });
+  });
+
+  it('should change subqueries read preference when using matchesKeyInQuery and doesNotMatchKeyInQuery to find through API', done => {
+    const databaseAdapter = Config.get(Parse.applicationId).database.adapter;
+
+    const obj0 = new Parse.Object('MyObject0');
+    obj0.set('boolKey', false);
+    const obj1 = new Parse.Object('MyObject1');
+    obj1.set('boolKey', true);
+    obj1.set('myObject0', obj0);
+    const obj2 = new Parse.Object('MyObject2');
+    obj2.set('boolKey', false);
+    obj2.set('myObject1', obj1);
+
+    Parse.Object.saveAll([obj0, obj1, obj2]).then(() => {
+      spyOn(databaseAdapter.database.serverConfig, 'cursor').and.callThrough();
+
+      const whereString = JSON.stringify({
+        boolKey: {
+          $select: {
+            query: {
+              className: 'MyObject0',
+              where: { boolKey: false },
+            },
+            key: 'boolKey',
+          },
+          $dontSelect: {
+            query: {
+              className: 'MyObject1',
+              where: { boolKey: true },
+            },
+            key: 'boolKey',
+          },
+        },
+      });
+
+      request({
+        method: 'GET',
+        url:
+          'http://localhost:8378/1/classes/MyObject2/?where=' +
+          whereString +
+          '&readPreference=SECONDARY_PREFERRED&subqueryReadPreference=SECONDARY',
+        headers: {
+          'X-Parse-Application-Id': 'test',
+          'X-Parse-REST-API-Key': 'rest',
+        },
+        json: true,
+      })
+        .then(response => {
+          expect(response.data.results.length).toBe(1);
+          expect(response.data.results[0].boolKey).toBe(false);
+
+          let myObjectReadPreference0 = null;
+          let myObjectReadPreference1 = null;
+          let myObjectReadPreference2 = null;
+          databaseAdapter.database.serverConfig.cursor.calls
+            .all()
+            .forEach(call => {
+              if (call.args[0].indexOf('MyObject0') >= 0) {
+                myObjectReadPreference0 =
+                  call.args[2].readPreference.preference;
+              }
+              if (call.args[0].indexOf('MyObject1') >= 0) {
+                myObjectReadPreference1 =
+                  call.args[2].readPreference.preference;
+              }
+              if (call.args[0].indexOf('MyObject2') >= 0) {
+                myObjectReadPreference2 =
+                  call.args[2].readPreference.preference;
+              }
+            });
+
+          expect(myObjectReadPreference0).toEqual(ReadPreference.SECONDARY);
+          expect(myObjectReadPreference1).toEqual(ReadPreference.SECONDARY);
+          expect(myObjectReadPreference2).toEqual(
+            ReadPreference.SECONDARY_PREFERRED
+          );
+
+          done();
+        })
+        .catch(done.fail);
     });
   });
 });

src/Adapters/Storage/Mongo/MongoStorageAdapter.js

@@ -926,6 +926,9 @@ export class MongoStorageAdapter implements StorageAdapter {
   }
 
   _parseReadPreference(readPreference: ?string): ?string {
+    if (readPreference) {
+      readPreference = readPreference.toUpperCase();
+    }
     switch (readPreference) {
       case 'PRIMARY':
         readPreference = ReadPreference.PRIMARY;

src/RestQuery.js

@@ -14,6 +14,9 @@ const AlwaysSelectedKeys = ['objectId', 'createdAt', 'updatedAt', 'ACL'];
 //   include
 //   keys
 //   redirectClassNameForKey
+//   readPreference
+//   includeReadPreference
+//   subqueryReadPreference
 function RestQuery(
   config,
   auth,
@@ -362,6 +365,8 @@ RestQuery.prototype.replaceInQuery = function() {
   if (this.restOptions.subqueryReadPreference) {
     additionalOptions.readPreference = this.restOptions.subqueryReadPreference;
     additionalOptions.subqueryReadPreference = this.restOptions.subqueryReadPreference;
+  } else if (this.restOptions.readPreference) {
+    additionalOptions.readPreference = this.restOptions.readPreference;
   }
 
   var subquery = new RestQuery(
@@ -421,6 +426,8 @@ RestQuery.prototype.replaceNotInQuery = function() {
   if (this.restOptions.subqueryReadPreference) {
     additionalOptions.readPreference = this.restOptions.subqueryReadPreference;
     additionalOptions.subqueryReadPreference = this.restOptions.subqueryReadPreference;
+  } else if (this.restOptions.readPreference) {
+    additionalOptions.readPreference = this.restOptions.readPreference;
   }
 
   var subquery = new RestQuery(
@@ -484,6 +491,8 @@ RestQuery.prototype.replaceSelect = function() {
   if (this.restOptions.subqueryReadPreference) {
     additionalOptions.readPreference = this.restOptions.subqueryReadPreference;
     additionalOptions.subqueryReadPreference = this.restOptions.subqueryReadPreference;
+  } else if (this.restOptions.readPreference) {
+    additionalOptions.readPreference = this.restOptions.readPreference;
   }
 
   var subquery = new RestQuery(
@@ -545,6 +554,8 @@ RestQuery.prototype.replaceDontSelect = function() {
   if (this.restOptions.subqueryReadPreference) {
     additionalOptions.readPreference = this.restOptions.subqueryReadPreference;
     additionalOptions.subqueryReadPreference = this.restOptions.subqueryReadPreference;
+  } else if (this.restOptions.readPreference) {
+    additionalOptions.readPreference = this.restOptions.readPreference;
   }
 
   var subquery = new RestQuery(
@@ -809,6 +820,8 @@ function includePath(config, auth, response, path, restOptions = {}) {
     includeRestOptions.readPreference = restOptions.includeReadPreference;
     includeRestOptions.includeReadPreference =
       restOptions.includeReadPreference;
+  } else if (restOptions.readPreference) {
+    includeRestOptions.readPreference = restOptions.readPreference;
   }
 
   const queryPromises = Object.keys(pointersHash).map(className => {

src/Routers/ClassesRouter.js

@@ -3,7 +3,13 @@ import rest from '../rest';
 import _ from 'lodash';
 import Parse from 'parse/node';
 
-const ALLOWED_GET_QUERY_KEYS = ['keys', 'include'];
+const ALLOWED_GET_QUERY_KEYS = [
+  'keys',
+  'include',
+  'readPreference',
+  'includeReadPreference',
+  'subqueryReadPreference',
+];
 
 export class ClassesRouter extends PromiseRouter {
   className(req) {
@@ -57,12 +63,21 @@ export class ClassesRouter extends PromiseRouter {
       }
     }
 
-    if (typeof body.keys == 'string') {
+    if (typeof body.keys === 'string') {
       options.keys = body.keys;
     }
     if (body.include) {
       options.include = String(body.include);
     }
+    if (typeof body.readPreference === 'string') {
+      options.readPreference = body.readPreference;
+    }
+    if (typeof body.includeReadPreference === 'string') {
+      options.includeReadPreference = body.includeReadPreference;
+    }
+    if (typeof body.subqueryReadPreference === 'string') {
+      options.subqueryReadPreference = body.subqueryReadPreference;
+    }
 
     return rest
       .get(
@@ -154,6 +169,9 @@ export class ClassesRouter extends PromiseRouter {
       'includeAll',
       'redirectClassNameForKey',
       'where',
+      'readPreference',
+      'includeReadPreference',
+      'subqueryReadPreference',
     ];
 
     for (const key of Object.keys(body)) {
@@ -188,6 +206,15 @@ export class ClassesRouter extends PromiseRouter {
     if (body.includeAll) {
       options.includeAll = true;
     }
+    if (typeof body.readPreference === 'string') {
+      options.readPreference = body.readPreference;
+    }
+    if (typeof body.includeReadPreference === 'string') {
+      options.includeReadPreference = body.includeReadPreference;
+    }
+    if (typeof body.subqueryReadPreference === 'string') {
+      options.subqueryReadPreference = body.subqueryReadPreference;
+    }
     return options;
   }
 

src/vendor/mongodbUrl.js

@@ -101,7 +101,7 @@ Url.prototype.parse = function(url, parseQueryString, slashesDenoteHost) {
       code === 10 /*\n*/ ||
       code === 12 /*\f*/ ||
       code === 160 /*\u00A0*/ ||
-      code === 65279 /*\uFEFF*/;
+      code === 65279; /*\uFEFF*/
     if (start === -1) {
       if (isWs) continue;
       lastPos = start = i;
@@ -193,7 +193,7 @@ Url.prototype.parse = function(url, parseQueryString, slashesDenoteHost) {
   // how the browser resolves relative URLs.
   if (slashesDenoteHost || proto || /^\/\/[^@\/]+@[^@\/]+/.test(rest)) {
     var slashes =
-      rest.charCodeAt(0) === 47 /*/*/ && rest.charCodeAt(1) === 47 /*/*/;
+      rest.charCodeAt(0) === 47 /*/*/ && rest.charCodeAt(1) === 47; /*/*/
     if (slashes && !(proto && hostlessProtocol[proto])) {
       rest = rest.slice(2);
       this.slashes = true;
@@ -285,7 +285,7 @@ Url.prototype.parse = function(url, parseQueryString, slashesDenoteHost) {
     // assume that it's an IPv6 address.
     var ipv6Hostname =
       hostname.charCodeAt(0) === 91 /*[*/ &&
-      hostname.charCodeAt(hostname.length - 1) === 93 /*]*/;
+      hostname.charCodeAt(hostname.length - 1) === 93; /*]*/
 
     // validate a little.
     if (!ipv6Hostname) {
@@ -868,11 +868,11 @@ Url.prototype.resolveObject = function(relative) {
 
   // put the host back
   if (psychotic) {
-    result.hostname = result.host = isAbsolute
-      ? ''
-      : srcPath.length
-        ? srcPath.shift()
-        : '';
+    if (isAbsolute) {
+      result.hostname = result.host = '';
+    } else {
+      result.hostname = result.host = srcPath.length ? srcPath.shift() : '';
+    }
     //occasionally the auth can get stuck only in host
     //this especially happens in cases like
     //url.resolveObject('mailto:local1@domain1', 'local2@domain2')