feat: naive support for GeometryCollection as Feature geometry (#2658)

Currently, we just skip those, but sometimes togeojson produces this
output from a KML.
This will create one feature per geometry, while in an ideal world this
should be a multi, but we lack reliable geometry tools to merge the
geometries without risking to create mistakes.
So let's say it's a first improvement.

umap/static/umap/js/modules/data/layer.js

@@ -492,8 +492,19 @@ export class DataLayer {
     const features = []
     this.sortFeatures(collection)
     for (const featureJson of collection) {
-      const feature = this.makeFeature(featureJson, sync)
+      if (featureJson.geometry?.type === 'GeometryCollection') {
-      if (feature) features.push(feature)
+        for (const geometry of featureJson.geometry.geometries) {
+          const feature = this.makeFeature({
+            type: 'Feature',
+            geometry,
+            properties: featureJson.properties,
+          })
+          if (feature) features.push(feature)
+        }
+      } else {
+        const feature = this.makeFeature(featureJson, sync)
+        if (feature) features.push(feature)
+      }
     }
     return features
   }

umap/tests/integration/test_import.py

@@ -435,6 +435,63 @@ def test_import_geometry_collection(live_server, page, tilelayer):
     expect(paths).to_have_count(2)
 
 
+def test_import_geometry_collection_in_feature(live_server, page, tilelayer):
+    data = {
+        "type": "Feature",
+        "properties": {"name": "foobar"},
+        "geometry": {
+            "type": "GeometryCollection",
+            "geometries": [
+                {"type": "Point", "coordinates": [-80.6608, 35.0493]},
+                {
+                    "type": "Polygon",
+                    "coordinates": [
+                        [
+                            [-80.6645, 35.0449],
+                            [-80.6634, 35.0460],
+                            [-80.6625, 35.0455],
+                            [-80.6638, 35.0442],
+                            [-80.6645, 35.0449],
+                        ]
+                    ],
+                },
+                {
+                    "type": "LineString",
+                    "coordinates": [
+                        [-80.66237, 35.05950],
+                        [-80.66269, 35.05926],
+                        [-80.66284, 35.05893],
+                        [-80.66308, 35.05833],
+                        [-80.66385, 35.04387],
+                        [-80.66303, 35.04371],
+                    ],
+                },
+            ],
+        },
+    }
+    page.goto(f"{live_server.url}/map/new/")
+    page.get_by_title("Open browser").click()
+    layers = page.locator(".umap-browser .datalayer")
+    markers = page.locator(".leaflet-marker-icon")
+    paths = page.locator("path")
+    expect(markers).to_have_count(0)
+    expect(paths).to_have_count(0)
+    expect(layers).to_have_count(0)
+    button = page.get_by_title("Import data")
+    expect(button).to_be_visible()
+    button.click()
+    textarea = page.locator(".umap-import textarea")
+    textarea.fill(json.dumps(data))
+    page.locator('select[name="format"]').select_option("geojson")
+    page.get_by_role("button", name="Import data", exact=True).click()
+    # A layer has been created
+    expect(layers).to_have_count(1)
+    expect(markers).to_have_count(1)
+    expect(paths).to_have_count(2)
+    # Geometries are treated as separate features.
+    expect(page.get_by_text("foobar")).to_have_count(3)
+
+
 def test_import_multipolygon(live_server, page, tilelayer):
     data = {
         "type": "Feature",