Add pipeline key to Aggregate (#4959)

* Add pipeline key to Aggregate

* clean up

* unit tests

Author: dplewis

CHANGELOG.md

@@ -3,10 +3,13 @@
 ### master
 [Full Changelog](https://github.com/parse-community/parse-server/compare/2.8.4...master)
 
+#### Improvements:
+* Adds Pipeline Operator to Aggregate Router
+
 ### 2.8.4
 [Full Changelog](https://github.com/parse-community/parse-server/compare/2.8.3...2.8.4)
 
-#### Improvements
+#### Improvements:
 * Adds ability to forward errors to express handler (#4697)
 * Adds ability to increment the push badge with an arbitrary value (#4889)
 * Adds ability to preserve the file names when uploading (#4915)

spec/AggregateRouter.spec.js

@@ -0,0 +1,69 @@
+const AggregateRouter = require('../lib/Routers/AggregateRouter').AggregateRouter;
+
+describe('AggregateRouter', () => {
+  it('get pipeline from Array', () => {
+    const body = [{
+      group: { objectId: {} }
+    }];
+    const expected = [ { $group: { _id: {} } } ];
+    const result = AggregateRouter.getPipeline(body);
+    expect(result).toEqual(expected);
+  });
+
+  it('get pipeline from Object', () => {
+    const body = {
+      group: { objectId: {} }
+    };
+    const expected = [ { $group: { _id: {} } } ];
+    const result = AggregateRouter.getPipeline(body);
+    expect(result).toEqual(expected);
+  });
+
+  it('get pipeline from Pipeline Operator (Array)', () => {
+    const body = {
+      pipeline: [{
+        group: { objectId: {} }
+      }]
+    };
+    const expected = [ { $group: { _id: {} } } ];
+    const result = AggregateRouter.getPipeline(body);
+    expect(result).toEqual(expected);
+  });
+
+  it('get pipeline from Pipeline Operator (Object)', () => {
+    const body = {
+      pipeline: {
+        group: { objectId: {} }
+      }
+    };
+    const expected = [ { $group: { _id: {} } } ];
+    const result = AggregateRouter.getPipeline(body);
+    expect(result).toEqual(expected);
+  });
+
+  it('get pipeline fails multiple keys in Array stage ', () => {
+    const body = [{
+      group: { objectId: {} },
+      match: { name: 'Test' },
+    }];
+    try {
+      AggregateRouter.getPipeline(body);
+    } catch (e) {
+      expect(e.message).toBe('Pipeline stages should only have one key found group, match');
+    }
+  });
+
+  it('get pipeline fails multiple keys in Pipeline Operator Array stage ', () => {
+    const body = {
+      pipeline: [{
+        group: { objectId: {} },
+        match: { name: 'Test' },
+      }]
+    };
+    try {
+      AggregateRouter.getPipeline(body);
+    } catch (e) {
+      expect(e.message).toBe('Pipeline stages should only have one key found group, match');
+    }
+  });
+});

spec/ParseQuery.Aggregate.spec.js

@@ -100,6 +100,24 @@ describe('Parse.Query Aggregate testing', () => {
       }).catch(done.fail);
   });
 
+  it('group by pipeline operator', async () => {
+    const options = Object.assign({}, masterKeyOptions, {
+      body: {
+        pipeline: {
+          group: { objectId: '$name' },
+        }
+      }
+    });
+    const resp = await rp.get(Parse.serverURL + '/aggregate/TestObject', options);
+    expect(resp.results.length).toBe(3);
+    expect(resp.results[0].hasOwnProperty('objectId')).toBe(true);
+    expect(resp.results[1].hasOwnProperty('objectId')).toBe(true);
+    expect(resp.results[2].hasOwnProperty('objectId')).toBe(true);
+    expect(resp.results[0].objectId).not.toBe(undefined);
+    expect(resp.results[1].objectId).not.toBe(undefined);
+    expect(resp.results[2].objectId).not.toBe(undefined);
+  });
+
   it('group by empty object', (done) => {
     const obj = new TestObject();
     const pipeline = [{

src/Routers/AggregateRouter.js

@@ -4,7 +4,7 @@ import * as middleware from '../middlewares';
 import Parse         from 'parse/node';
 import UsersRouter   from './UsersRouter';
 
-const BASE_KEYS = ['where', 'distinct'];
+const BASE_KEYS = ['where', 'distinct', 'pipeline'];
 
 const PIPELINE_KEYS = [
   'addFields',
@@ -41,24 +41,10 @@ export class AggregateRouter extends ClassesRouter {
   handleFind(req) {
     const body = Object.assign(req.body, ClassesRouter.JSONFromQuery(req.query));
     const options = {};
-    let pipeline = [];
-
-    if (Array.isArray(body)) {
-      pipeline = body.map((stage) => {
-        const stageName = Object.keys(stage)[0];
-        return this.transformStage(stageName, stage);
-      });
-    } else {
-      const stages = [];
-      for (const stageName in body) {
-        stages.push(this.transformStage(stageName, body));
-      }
-      pipeline = stages;
-    }
     if (body.distinct) {
       options.distinct = String(body.distinct);
     }
-    options.pipeline = pipeline;
+    options.pipeline = AggregateRouter.getPipeline(body);
     if (typeof body.where === 'string') {
       body.where = JSON.parse(body.where);
     }
@@ -72,7 +58,48 @@ export class AggregateRouter extends ClassesRouter {
     });
   }
 
-  transformStage(stageName, stage) {
+  /* Builds a pipeline from the body. Originally the body could be passed as a single object,
+   * and now we support many options
+   *
+   * Array
+   *
+   * body: [{
+   *   group: { objectId: '$name' },
+   * }]
+   *
+   * Object
+   *
+   * body: {
+   *   group: { objectId: '$name' },
+   * }
+   *
+   *
+   * Pipeline Operator with an Array or an Object
+   *
+   * body: {
+   *   pipeline: {
+   *     group: { objectId: '$name' },
+   *   }
+   * }
+   *
+   */
+  static getPipeline(body) {
+    let pipeline = body.pipeline || body;
+
+    if (!Array.isArray(pipeline)) {
+      pipeline = Object.keys(pipeline).map((key) => { return { [key]: pipeline[key] } });
+    }
+
+    return pipeline.map((stage) => {
+      const keys = Object.keys(stage);
+      if (keys.length != 1) {
+        throw new Error(`Pipeline stages should only have one key found ${keys.join(', ')}`);
+      }
+      return AggregateRouter.transformStage(keys[0], stage);
+    });
+  }
+
+  static transformStage(stageName, stage) {
     if (ALLOWED_KEYS.indexOf(stageName) === -1) {
       throw new Parse.Error(
         Parse.Error.INVALID_QUERY,