From eb4ad71cc91613ce8c4c8043e425a206907f3a8b Mon Sep 17 00:00:00 2001
From: Joel Lord <joelphy@gmail.com>
Date: Mon, 24 Jan 2022 06:02:52 -0500
Subject: [PATCH] Adding support for arrayFilters in updates

This PR is for the feature request [#4247](https://github.com/realm/realm-js/issues/4247).

This PR adds support for arrayFilters by passing the arrayFilters parameter to the Realm serverless function.

Additional testing was added to cover the case of an update with arrayFilters.
---
 docs/sync.js                                  |  4 +++
 lib/mongo-client.js                           |  2 ++
 .../src/remote-mongodb-service.test.ts        | 28 +++++++++++++++++++
 .../MongoDBService/MongoDBCollection.ts       |  2 ++
 types/services.d.ts                           |  4 +++
 5 files changed, 40 insertions(+)

diff --git a/docs/sync.js b/docs/sync.js
index 389a74191d0..6785b332fb6 100644
--- a/docs/sync.js
+++ b/docs/sync.js
@@ -1279,6 +1279,8 @@ class MongoDBCollection {
    * @param {object} [options] Additional options to apply.
    * @param {boolean} [options.upsert=false] if true, indicates that MongoDB should insert a new document that matches the
    * query filter when the query does not match any existing documents in the collection.
+   * @param {object[]} [options.arrayFilters=false] if provided, indicates the arrayFilters to use to update 
+   * an embedded array
    * @returns {Promise<Realm.MongoDBCollection~UpdateResult>}
    */
   updateOne(filter, update, options) {}
@@ -1291,6 +1293,8 @@ class MongoDBCollection {
    * @param {object} [options] Additional options to apply.
    * @param {boolean} [options.upsert=false] if true, indicates that MongoDB should insert a new document that matches the
    * query filter when the query does not match any existing documents in the collection.
+   * @param {object[]} [options.arrayFilters=false] if provided, indicates the arrayFilters to use to update 
+   * an embedded array
    * @returns {Promise<Realm.MongoDBCollection~UpdateResult>}
    */
   updateMany(filter, update, options) {}
diff --git a/lib/mongo-client.js b/lib/mongo-client.js
index 06021fb879e..d23d556fed8 100644
--- a/lib/mongo-client.js
+++ b/lib/mongo-client.js
@@ -183,6 +183,7 @@ class MongoDBCollection {
       query: filter,
       update,
       upsert: options.upsert,
+      arrayFilters: options.arrayFilters,
     });
   }
 
@@ -194,6 +195,7 @@ class MongoDBCollection {
       query: filter,
       update,
       upsert: options.upsert,
+      arrayFilters: options.arrayFilters,
     });
   }
 
diff --git a/packages/realm-web-integration-tests/src/remote-mongodb-service.test.ts b/packages/realm-web-integration-tests/src/remote-mongodb-service.test.ts
index 0194ce1fce9..f50199dc366 100644
--- a/packages/realm-web-integration-tests/src/remote-mongodb-service.test.ts
+++ b/packages/realm-web-integration-tests/src/remote-mongodb-service.test.ts
@@ -293,6 +293,34 @@ describe("Remote MongoDB", () => {
     expect(result.modifiedCount).equals(3);
   });
 
+  it("can update documents using array filters", async () => {
+    const collection = getCollection<TestDocument>();
+    // Insert a document with an embedded array
+    const insertResult = await collection.insertOne([
+      { runId, name: "arrayFilter", values: [ {condition: 1, status: false}, {condition: 2, status: false} ] },
+    ]);
+    expect(insertResult.insertedIds.length).equals(1);
+
+    // Update the array element with condition == 1 to have status == true
+    let filter = { runId, name: "arrayFilter" };
+    let update = {"$set": {"values.$[element].status": true}};
+    let arrayFilters = [{"element.condition": 1 }];
+    const result = await collection.updateOne(filter, update, { arrayFilters });
+    // Check the result
+    expect(typeof result).equals("object");
+    expect(result.matchedCount).equals(1);
+    expect(result.modifiedCount).equals(1);
+
+    // Fetch the document to ensure that only the filtered elements of the array were updated
+    const doc = await collection.findOne({ runId, name: "arrayFilter" });
+    if (doc === null) {
+      throw new Error("Expected a result");
+    } else {
+      expect(doc.values.find(e => e.condition === 1).status).equals(true);
+      expect(doc.values.find(e => e.condition === 2).status).equals(false);
+    }
+  });
+
   it("upserts when updating many non-existing documents", async () => {
     const collection = getCollection<TestDocument>();
     // Delete the document with the last name (Charlie)
diff --git a/packages/realm-web/src/services/MongoDBService/MongoDBCollection.ts b/packages/realm-web/src/services/MongoDBService/MongoDBCollection.ts
index 87292ac87e7..1c274f9bb1b 100644
--- a/packages/realm-web/src/services/MongoDBService/MongoDBCollection.ts
+++ b/packages/realm-web/src/services/MongoDBService/MongoDBCollection.ts
@@ -215,6 +215,7 @@ export class MongoDBCollection<T extends Document> implements Realm.Services.Mon
       query: filter,
       update,
       upsert: options.upsert,
+      arrayFilters: options.arrayFilters,
     });
   }
 
@@ -230,6 +231,7 @@ export class MongoDBCollection<T extends Document> implements Realm.Services.Mon
       query: filter,
       update,
       upsert: options.upsert,
+      arrayFilters: options.arrayFilters,
     });
   }
 
diff --git a/types/services.d.ts b/types/services.d.ts
index 26d13743065..d9bba6962c9 100644
--- a/types/services.d.ts
+++ b/types/services.d.ts
@@ -122,6 +122,10 @@ declare namespace Realm {
          * When true, creates a new document if no document matches the query.
          */
         readonly upsert?: boolean;
+        /**
+         * Array Filters
+         */
+        readonly arrayFilters?: Filter[]
       }
 
       /**