setProperty function doesn't set an empty array if property doesn't exist

CONTRIBUTING.md

@@ -42,7 +42,7 @@ Before committing, be sure to install the "Prettier" precommit hook that will re
 In order to enable the "Prettier" precommit hook, at the root of the project, run:
 
 ```console
-$ yarn run install
+$ yarn install
 $ yarn run prepare
 ```
 

front/src/Phaser/Game/GameScene.ts

@@ -1075,11 +1075,13 @@ ${escapedMessage}
             console.warn('Could not find layer "' + layerName + '" when calling setProperty');
             return;
         }
-        const property = (layer.properties as ITiledMapLayerProperty[])?.find(
+        if (layer.properties === undefined) {
+            layer.properties = [];
+        }
+        const property = (layer.properties as ITiledMapLayerProperty[]).find(
             (property) => property.name === propertyName
         );
         if (property === undefined) {
-            layer.properties = [];
             layer.properties.push({ name: propertyName, type: typeof propertyValue, value: propertyValue });
             return;
         }

maps/tests/Metadata/setTiles.json

@@ -286,11 +286,6 @@
                          "name":"jitsiTrigger",
                          "type":"string",
                          "value":"onaction"
-                        },
-                        {
-                         "name":"jitsiUrl",
-                         "type":"string",
-                         "value":"meet.jit.si"
                         }]
                 },
                 {