From 3e95c7df6ae7de6a3a406dfb61dd044ea905456f Mon Sep 17 00:00:00 2001
From: Beau Shaw <techtbeau@gmail.com>
Date: Wed, 30 Oct 2024 21:34:47 -0500
Subject: [PATCH] fix(mongodb): Fix mongo count (#3541)

---
 packages/mongodb/src/adapter.ts     | 18 ++++++++++++------
 packages/mongodb/test/index.test.ts | 23 +++++++++++++----------
 2 files changed, 25 insertions(+), 16 deletions(-)

diff --git a/packages/mongodb/src/adapter.ts b/packages/mongodb/src/adapter.ts
index b640bf395d..2b4a2036a6 100644
--- a/packages/mongodb/src/adapter.ts
+++ b/packages/mongodb/src/adapter.ts
@@ -148,10 +148,6 @@ export class MongoDbAdapter<
       pipeline.push({ $sort: filters.$sort })
     }
 
-    if (filters.$select !== undefined) {
-      pipeline.push({ $project: this.getProjection(filters.$select) })
-    }
-
     if (filters.$skip !== undefined) {
       pipeline.push({ $skip: filters.$skip })
     }
@@ -160,6 +156,10 @@ export class MongoDbAdapter<
       pipeline.push({ $limit: filters.$limit })
     }
 
+    if (filters.$select !== undefined) {
+      pipeline.push({ $project: this.getProjection(filters.$select) })
+    }
+
     return pipeline
   }
 
@@ -167,6 +167,7 @@ export class MongoDbAdapter<
     if (!select) {
       return undefined
     }
+
     if (Array.isArray(select)) {
       if (!select.includes(this.id)) {
         select = [this.id, ...select]
@@ -213,6 +214,8 @@ export class MongoDbAdapter<
     if (params.pipeline) {
       const aggregateParams = {
         ...params,
+        paginate: false,
+        pipeline: [...params.pipeline, { $count: 'total' }],
         query: {
           ...params.query,
           $select: [this.id],
@@ -221,8 +224,11 @@ export class MongoDbAdapter<
           $limit: undefined
         }
       }
-      const result = await this.aggregateRaw(aggregateParams).then((result) => result.toArray())
-      return result.length
+      const [result] = await this.aggregateRaw(aggregateParams).then((result) => result.toArray())
+      if (!result) {
+        return 0
+      }
+      return result.total
     }
 
     const model = await this.getModel(params)
diff --git a/packages/mongodb/test/index.test.ts b/packages/mongodb/test/index.test.ts
index 7aec6e887d..5d3d2f6fc5 100644
--- a/packages/mongodb/test/index.test.ts
+++ b/packages/mongodb/test/index.test.ts
@@ -29,6 +29,7 @@ const testSuite = adapterTests([
   '.remove + multi',
   '.remove + multi no pagination',
   '.remove + id + query id',
+  '.remove + NotFound',
   '.update',
   '.update + $select',
   '.update + id + query',
@@ -83,11 +84,6 @@ const testSuite = adapterTests([
   'params.adapter + multi'
 ])
 
-const defaultPaginate = {
-  default: 10,
-  max: 50
-}
-
 describe('Feathers MongoDB Service', () => {
   const personSchema = {
     $id: 'Person',
@@ -573,12 +569,19 @@ describe('Feathers MongoDB Service', () => {
     it('can count documents with aggregation', async () => {
       const service = app.service('people')
       const paginateBefore = service.options.paginate
-      service.options.paginate = defaultPaginate
-      const query = { age: { $gte: 25 } }
-      const findResult = await app.service('people').find({ query })
-      const aggregationResult = await app.service('people').find({ query, pipeline: [] })
 
-      assert.deepStrictEqual(findResult.total, aggregationResult.total)
+      const test = async (paginate: any) => {
+        service.options.paginate = paginate
+        const query = { age: { $gte: 25 } }
+        const findResult = await app.service('people').find({ query })
+        const aggregationResult = await app.service('people').find({ query, pipeline: [] })
+        assert.deepStrictEqual(findResult.total, aggregationResult.total)
+      }
+
+      await test({ default: 10, max: 50 })
+      // There are 2 people with age >= 25.
+      // Test that aggregation works when results are less than default
+      await test({ default: 1, max: 50 })
 
       service.options.paginate = paginateBefore
     })