Add tests

src/test/saveStateHandler.test.ts

@@ -0,0 +1,44 @@
+import SaveStateHandler from "../saveStateHandler";
+
+const createSaveStateHandler = () => {
+    const addToSelection = jest.fn();
+    const getNodeById = jest.fn();
+    const getSelectedNodes = jest.fn();
+    const getTree = jest.fn();
+    const openNode = jest.fn();
+    const refreshElements = jest.fn();
+    const removeFromSelection = jest.fn();
+
+    return new SaveStateHandler({
+        addToSelection,
+        getNodeById,
+        getSelectedNodes,
+        getTree,
+        openNode,
+        refreshElements,
+        removeFromSelection,
+        saveState: true,
+    });
+};
+
+describe("getStateFromStorage", () => {
+    afterEach(() => {
+        localStorage.clear();
+    });
+
+    it("returns null when the state is not in local storage", () => {
+        localStorage.clear();
+
+        const saveStateHandler = createSaveStateHandler();
+        expect(saveStateHandler.getStateFromStorage()).toBeNull();
+    });
+
+    it("returns an array of selected nodes when 'selected_node' in the states is a number", () => {
+        localStorage.setItem("tree", JSON.stringify({ selected_node: 123 }));
+
+        const saveStateHandler = createSaveStateHandler();
+        expect(saveStateHandler.getStateFromStorage()).toEqual({
+            selected_node: [123],
+        });
+    });
+});