Fix method for fetching all images in light version with no argument

Author: eburtin

src/collections/image-instance-collection.js

@@ -46,7 +46,7 @@ export default class ImageInstanceCollection extends Collection {
      * @returns {Array<{id: Number, filename: String, originalFilename: String, projectName: String, project: Number}>}
      *          The list of images (light format)
      */
-    static async fetchAllLight({max=0, offset=0}) {
+    static async fetchAllLight({max=0, offset=0}={}) {
         let {data} = await Cytomine.instance.api.get(`user/0/imageinstance/light.json?max=${max}&offset=${offset}`); // {user} value ignored in backend => set to 0
         return data.collection;
     }

tests/test-image-instance.js

@@ -226,6 +226,11 @@ describe("ImageInstance", function() {
                     expect(listId).to.include(image.id);
                 });
             });
+
+            it("Fetch light version", async function() {
+                let collection = await ImageInstanceCollection.fetchAllLight();
+                expect(collection).to.have.lengthOf.at.least(nbImageInstances);
+            });
         });
 
         describe("Working with the collection", function() {