fix: GeoPoint distance queries fail with an internal server error on MongoDB >=8.3

.github/workflows/ci.yml

@@ -187,6 +187,10 @@ jobs:
             MONGODB_VERSION: 8.0.4
             MONGODB_TOPOLOGY: replset
             NODE_VERSION: 24.11.0
+          - name: MongoDB 8.3, ReplicaSet
+            MONGODB_VERSION: 8.3.4
+            MONGODB_TOPOLOGY: replset
+            NODE_VERSION: 24.11.0
           - name: Redis Cache
             PARSE_SERVER_TEST_CACHE: redis
             MONGODB_VERSION: 8.0.4

spec/MongoCollection.spec.js

@@ -0,0 +1,101 @@
+'use strict';
+
+const { MongoClient } = require('mongodb');
+const MongoCollection = require('../lib/Adapters/Storage/Mongo/MongoCollection').default;
+const { findGeoIndexField } = require('../lib/Adapters/Storage/Mongo/MongoCollection');
+
+describe_only_db('mongo')('MongoCollection', () => {
+  describe('findGeoIndexField', () => {
+    it('extracts the field constrained by $nearSphere', () => {
+      const query = { construct: 'line', location: { $nearSphere: [-121.5, 38.5], $maxDistance: 2.5 } };
+      expect(findGeoIndexField(query)).toBe('location');
+    });
+
+    it('extracts the field constrained by $near', () => {
+      expect(findGeoIndexField({ region: { $near: [0, 0] } })).toBe('region');
+    });
+
+    it('recurses into $and to find the geo field', () => {
+      const query = { $and: [{ a: 1 }, { loc: { $nearSphere: [0, 0] } }] };
+      expect(findGeoIndexField(query)).toBe('loc');
+    });
+
+    it('returns undefined when there is no geo operator', () => {
+      expect(findGeoIndexField({ a: 1, b: { $gt: 2 } })).toBeUndefined();
+    });
+
+    it('returns undefined for empty / non-object queries', () => {
+      expect(findGeoIndexField({})).toBeUndefined();
+      expect(findGeoIndexField(null)).toBeUndefined();
+      expect(findGeoIndexField(undefined)).toBeUndefined();
+    });
+
+    it('does not treat $geoWithin as requiring an index', () => {
+      const query = { location: { $geoWithin: { $centerSphere: [[0, 0], 1] } } };
+      expect(findGeoIndexField(query)).toBeUndefined();
+    });
+
+    it('does not recurse into $or (MongoDB forbids $near inside $or)', () => {
+      const query = { $or: [{ a: 1 }, { loc: { $nearSphere: [0, 0] } }] };
+      expect(findGeoIndexField(query)).toBeUndefined();
+    });
+  });
+
+  describe('lazy geo index creation', () => {
+    const collectionName = 'MongoCollectionLazyGeoIndexTest';
+    let client;
+    let rawCollection;
+
+    const geoQuery = { location: { $nearSphere: [-121.5, 38.5], $maxDistance: 2.526 } };
+
+    beforeEach(async () => {
+      client = new MongoClient(databaseURI);
+      await client.connect();
+      rawCollection = client.db().collection(collectionName);
+      // Start from a clean collection with NO geo index so the lazy-creation path is exercised.
+      await rawCollection.drop().catch(() => {});
+      await rawCollection.insertMany([
+        { _id: '1', location: [-121, 38] },
+        { _id: '2', location: [-122, 39] },
+      ]);
+    });
+
+    afterEach(async () => {
+      await rawCollection.drop().catch(() => {});
+      await client.close();
+    });
+
+    it('creates a 2d index on demand and returns results for a $nearSphere query on an un-indexed field', async () => {
+      const mongoCollection = new MongoCollection(rawCollection);
+      const results = await mongoCollection.find(geoQuery);
+      expect(results.length).toBe(2);
+      const indexes = await rawCollection.indexes();
+      const hasGeoIndex = indexes.some(index => index.key && index.key.location === '2d');
+      expect(hasGeoIndex).toBe(true);
+    });
+
+    it_only_mongodb_version('>=8.3')('MongoDB 8.3+ reports the geoNear "no index" error without the field name', async () => {
+      let error;
+      try {
+        await rawCollection.find(geoQuery).toArray();
+      } catch (e) {
+        error = e;
+      }
+      expect(error).toBeDefined();
+      expect(error.message).toMatch(/unable to find index for .geoNear/);
+      expect(error.message).not.toMatch(/field=/);
+    });
+
+    it_only_mongodb_version('<8.3')('older MongoDB reports the geoNear "no index" error with the field name', async () => {
+      let error;
+      try {
+        await rawCollection.find(geoQuery).toArray();
+      } catch (e) {
+        error = e;
+      }
+      expect(error).toBeDefined();
+      expect(error.message).toMatch(/unable to find index for .geoNear/);
+      expect(error.message).toMatch(/field=location/);
+    });
+  });
+});

src/Adapters/Storage/Mongo/MongoCollection.js

@@ -1,6 +1,48 @@
 const mongodb = require('mongodb');
 const Collection = mongodb.Collection;
 
+// Query operators that require a geospatial index and therefore trigger
+// on-demand `2d` index creation. `$geoWithin` / `$geoIntersects` are intentionally
+// excluded: they can run as a collection scan and never raise a "no index" error.
+const GEO_INDEX_QUERY_OPERATORS = ['$nearSphere', '$near', '$geoNear'];
+
+// Find the field in a Mongo query document that is constrained by a geo operator
+// requiring a geospatial index. Returns the field name (e.g. 'location'), or
+// undefined if none is found. Used as the reliable source of truth for on-demand
+// geo index creation, since the MongoDB error message that used to carry the field
+// name (`... field=<name> ...`) was dropped in MongoDB 8.3+.
+//
+// A geo-near expression must be top-level or inside `$and`: MongoDB rejects it inside
+// `$or` / `$nor` ("geo $near must be top-level expr") and forbids more than one per
+// query ("Too many geoNear expressions"). So there is at most one field to find, and
+// `$and` is the only combinator we need to recurse into.
+export function findGeoIndexField(query) {
+  if (!query || typeof query !== 'object') {
+    return undefined;
+  }
+  for (const field of Object.keys(query)) {
+    const value = query[field];
+    // Recurse into `$and`, which holds an array of sub-queries.
+    if (field === '$and' && Array.isArray(value)) {
+      for (const subQuery of value) {
+        const found = findGeoIndexField(subQuery);
+        if (found) {
+          return found;
+        }
+      }
+      continue;
+    }
+    if (
+      value &&
+      typeof value === 'object' &&
+      GEO_INDEX_QUERY_OPERATORS.some(op => Object.prototype.hasOwnProperty.call(value, op))
+    ) {
+      return field;
+    }
+  }
+  return undefined;
+}
+
 export default class MongoCollection {
   _mongoCollection: Collection;
 
@@ -51,8 +93,12 @@ export default class MongoCollection {
       if (error.code != 17007 && !error.message.match(/unable to find index for .geoNear/)) {
         throw error;
       }
-      // Figure out what key needs an index
-      const key = error.message.match(/field=([A-Za-z_0-9]+) /)[1];
+      // Figure out which field needs a geo index.
+      // Older MongoDB embeds the field name in the error message (`... field=<name> ...`);
+      // MongoDB 8.3+ shortened the message to `unable to find index for $geoNear query`
+      // and no longer includes it, so fall back to reading the field from the query itself.
+      const messageMatch = error.message.match(/field=([A-Za-z_0-9]+) /);
+      const key = (messageMatch && messageMatch[1]) || findGeoIndexField(query);
       if (!key) {
         throw error;
       }