adds export for AggregateCommand to allow custom queries with MongoDB (…

…#410)

Signed-off-by: Marc J. Schmidt <marc@marcjschmidt.de>
Co-authored-by: Marc J. Schmidt <marc@marcjschmidt.de>

packages/mongo/index.ts

@@ -16,4 +16,5 @@ export * from './src/query.resolver.js';
 export * from './src/query.js';
 export * from './src/client/client.js';
 
-export { UpdateCommand } from './src/client/command/update.js';
+export { UpdateCommand } from './src/client/command/update.js';
+export { AggregateCommand }  from './src/client/command/aggregate.js';

packages/mongo/tests/mongo-aggregate.spec.ts

@@ -0,0 +1,80 @@
+import { expect, test } from '@jest/globals';
+import {
+    entity, MongoId, PrimaryKey, ReflectionClass,
+} from '@deepkit/type';
+import { createDatabase } from './utils';
+import { AggregateCommand } from '../src/client/command/aggregate';
+
+Error.stackTraceLimit = 100;
+
+@entity.name('Model').collection('test_aggregate')
+export class Model {
+    _id: MongoId & PrimaryKey = '';
+
+    prodId: string = '';
+
+    constructor(public name: string) {
+    }
+}
+
+
+test('raw AggregateCommand', async () => {
+    const db = await createDatabase('testing');
+    await db.query(Model).deleteMany();
+
+    const item = new Model('foo');
+    item.prodId = 'AA';
+
+    const item2 = new Model('foo2');
+    item2.prodId = 'AA';
+
+    const item3 = new Model('foo3');
+    item3.prodId = 'BB';
+
+    await db.persist(item);
+    await db.persist(item2);
+    await db.persist(item3);
+
+    /* Expected Query result example
+    [
+      {
+        _id: { prodId: 'AA' },
+        uniqueIds: [ '63e69569a82a66fedb000001', '63e69569a82a66fedb000002' ],
+        count: 2
+      }
+    ]
+     */
+
+    class ResultId {
+        prodId!: string;
+    }
+
+    class DoubleEntries {
+        _id!: ResultId;
+        uniqueIds!: MongoId[];
+        count!: number;
+    }
+
+    // this will find records with the same prodId and list their _id
+    const pipeline = [{
+        $group: {
+            _id: {prodId: '$prodId'}, uniqueIds: {$addToSet: '$_id'}, count: {$sum: 1},
+        },
+    }, {
+        $match: {
+            count: {$gte: 2},
+        },
+    },];
+
+    const resultSchema = ReflectionClass.from(DoubleEntries);
+    const schema = ReflectionClass.from(Model);
+    const command = new AggregateCommand(schema, pipeline, resultSchema);
+    const res = await db.adapter.client.execute(command);
+
+    // console.log(res);
+
+    expect(res).toMatchObject([{
+        _id: {prodId: 'AA'}, uniqueIds: [expect.any(String), expect.any(String)], count: 2
+    }]);
+
+});