Add GeoDjango support

[timgraham]

No description provided.

[timgraham]

Adding both .github/workflows/test-python-geo.yml and .github/workflows/test-python-atlas-geo.yml might be redundant. (Are there any notable differences in GEO support on Atlas?) When the Atlas build ran with transactions, it was perhaps slightly more useful.

[Jibola]

There are no differences between Geospatial querying and indexing done on Atlas vs. what is done on local atlas.

[timgraham]

I meant that test-python-geo.yml uses supercharge/mongodb-github-action (is this "standalone"?) and test-python-atlas-geo.yml uses the Atlas VM.

[Jibola]

Overall, looks good! Added a few questions, and would just like a test to confirm the 5 (of 6) data types can be inserted properly (even if un-queryable at the moment)

[Jibola]

There are no differences between Geospatial querying and indexing done on Atlas vs. what is done on local atlas.

[Jibola]

Can we add a link here?

Suggested change

	besides 4326 (WGS84) .
	besides `4326 (WGS84) <https://spatialreference.org/ref/epsg/4326/>` .

[Jibola]

Any reservation to having it be an extension for us django-mongodb-backend[geos] or something of that nature?

[timgraham]

The geospatial libraries aren't Python packages.

[Jibola]

Can we have a test that confirms field storage and database schema? For MongoDB GeoJSON format still requires:
{ type: <GeoJSON Type>, ...} as the data format. I see in the Adapter does the work to ensure proper schema conversion, but I think it still helps to have a test.

[timgraham]

Like a query with pymongo.find()? Another thing to consider (if it assuages your concern) is that MongoDB raises an error (e.g. "can't extract geo keys") if a spatial index receives invalid data.

[Jibola]

Can you add a link to the MongoDB GeoJSON Object types in this docstring?
https://www.mongodb.com/docs/manual/reference/geojson/

[timgraham]

would just like a test to confirm the 5 (of 6) data types can be inserted properly (even if un-queryable at the moment)

7 out of 7 work (PointField, LineStringField, PolygonField, MultiPointField, MultiLineStringField, MultiPolygonField, GeometryCollectionField).

It's tested in Django's test suite. Surprisingly, I had to add some tests for a few of the fields to our Django fork:

Add tests for MultiPointField, MultiLineStringField, and GeometryCollectionField

commit 9dc4d37d7e8bb514922bd51c1a0940f5537e2c35
Author: Tim Graham <timograham@gmail.com>
Date:   Fri Jul 25 15:41:50 2025 -0400

    Add tests for MultiPointField, MultiLineStringField, and GeometryCollectionField
    
    These should be contributed upstream to Django.

diff --git a/tests/gis_tests/geoapp/models.py b/tests/gis_tests/geoapp/models.py
index 2c13c827c6..c7acb653d3 100644
--- a/tests/gis_tests/geoapp/models.py
+++ b/tests/gis_tests/geoapp/models.py
@@ -102,3 +102,15 @@ class ManyPointModel(NamedModel):
     point1 = models.PointField()
     point2 = models.PointField()
     point3 = models.PointField(srid=3857)
+
+
+class Points(models.Model):
+    geom = models.MultiPointField()
+
+
+class Lines(models.Model):
+    geom = models.MultiLineStringField()
+
+
+class GeometryCollections(models.Model):
+    geom = models.GeometryCollectionField()
diff --git a/tests/gis_tests/geoapp/tests.py b/tests/gis_tests/geoapp/tests.py
index f9abae129f..945d80a563 100644
--- a/tests/gis_tests/geoapp/tests.py
+++ b/tests/gis_tests/geoapp/tests.py
@@ -26,10 +26,13 @@ from .models import (
     City,
     Country,
     Feature,
+    GeometryCollections,
+    Lines,
     MinusOneSRID,
     MultiFields,
     NonConcreteModel,
     PennsylvaniaCity,
+    Points,
     State,
     ThreeDimensionalFeature,
     Track,
@@ -269,6 +272,47 @@ class GeoModelTest(TestCase):
             self.assertEqual(feature.geom.srid, g.srid)
 
 
+# TODO: contribute these tests added to the MongoDB fork upstream to Django.
+class SaveLoadTests(TestCase):
+    def test_multi_line_string_field(self):
+        geom = MultiLineString(
+            LineString((0, 0), (1, 1), (5, 5)),
+            LineString((0, 0), (0, 5), (5, 5), (5, 0), (0, 0)),
+        )
+        obj = Lines.objects.create(geom=geom)
+        obj.refresh_from_db()
+        self.assertEqual(obj.geom.tuple, geom.tuple)
+
+    def test_multi_line_string_with_linear_ring(self):
+        # LinearRings are transformed to LineString
+        geom = MultiLineString(
+            LineString((0, 0), (1, 1), (5, 5)),
+            LinearRing((0, 0), (0, 5), (5, 5), (5, 0), (0, 0)),
+        )
+        obj = Lines.objects.create(geom=geom)
+        obj.refresh_from_db()
+        self.assertEqual(obj.geom.tuple, geom.tuple)
+        self.assertEqual(obj.geom[0].tuple, geom[0].tuple)
+        self.assertEqual(obj.geom[1].__class__.__name__, "LineString")
+        self.assertEqual(obj.geom[1].tuple, geom[1].tuple)
+
+    def test_multi_point_field(self):
+        geom = MultiPoint(Point(1, 1), Point(0, 0))
+        obj = Points.objects.create(geom=geom)
+        obj.refresh_from_db()
+        self.assertEqual(obj.geom, geom)
+
+    def test_geometry_collection_field(self):
+        geom = GeometryCollection(
+            Point(2, 2),
+            LineString((0, 0), (2, 2)),
+            Polygon(LinearRing((0, 0), (0, 5), (5, 5), (5, 0), (0, 0))),
+        )
+        obj = GeometryCollections.objects.create(geom=geom)
+        obj.refresh_from_db()
+        self.assertEqual(obj.geom, geom)
+
+
 class GeoLookupTest(TestCase):
     fixtures = ["initial"]

[aclark4life]

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