Add support for custom properties in toFeatureCollectionJson method

API.md

@@ -21,7 +21,7 @@ Geometry classes can be also created by these static methods:
 
 * `toArray()` - Serializes the geometry object into a GeoJSON associative array.
 * `toJson()` - Serializes the geometry object into an GeoJSON string.
-* `toFeatureCollectionJson()` - Serializes the geometry object into an GeoJSON's FeatureCollection string.
+* `toFeatureCollectionJson(array $properties = [])` - Serializes the geometry object into an GeoJSON's FeatureCollection string, with optional `properties` to be added to each feature.
 * `toWkt()` - Serializes the geometry object into a WKT.
 * `toWkb()` - Serializes the geometry object into a WKB.
 * `getCoordinates()` - Returns the coordinates of the geometry object.

src/Objects/Geometry.php

@@ -153,9 +153,13 @@ public function toArray(): array
     }
 
     /**
+     * @param array<array<string, mixed>> $properties
+     * 
+     * @return string
+     *
      * @throws JsonException
      */
-    public function toFeatureCollectionJson(): string
+    public function toFeatureCollectionJson(array $properties = []): string
     {
         if (static::class === GeometryCollection::class) {
             /** @var GeometryCollection $this */
@@ -164,10 +168,10 @@ public function toFeatureCollectionJson(): string
             $geometries = collect([$this]);
         }
 
-        $features = $geometries->map(static function (self $geometry): array {
+        $features = $geometries->map(static function (self $geometry, $index) use ($properties) {
             return [
                 'type' => 'Feature',
-                'properties' => [],
+                'properties' => $properties[$index] ?? [],
                 'geometry' => $geometry->toArray(),
             ];
         });

tests/Objects/GeometryCollectionTest.php

@@ -159,10 +159,14 @@
         ]),
         new Point(0, 180),
     ]);
+    $properties = [
+        ['name' => 'Polygon property', 'description' => 'Polygon description'],
+        ['name' => 'Point property', 'description' => 'Point description'],
+    ];
 
-    $featureCollectionJson = $geometryCollection->toFeatureCollectionJson();
+    $featureCollectionJson = $geometryCollection->toFeatureCollectionJson($properties);
 
-    $expectedFeatureCollectionJson = '{"type":"FeatureCollection","features":[{"type":"Feature","properties":[],"geometry":{"type":"Polygon","coordinates":[[[180,0],[179,1],[178,2],[177,3],[180,0]]]}},{"type":"Feature","properties":[],"geometry":{"type":"Point","coordinates":[180,0]}}]}';
+    $expectedFeatureCollectionJson = '{"type":"FeatureCollection","features":[{"type":"Feature","properties":{"name":"Polygon property","description":"Polygon description"},"geometry":{"type":"Polygon","coordinates":[[[180,0],[179,1],[178,2],[177,3],[180,0]]]}},{"type":"Feature","properties":{"name":"Point property","description":"Point description"},"geometry":{"type":"Point","coordinates":[180,0]}}]}';
     expect($featureCollectionJson)->toBe($expectedFeatureCollectionJson);
 });