Add test

src/test/nodeElement/borderDropHint.test.ts

@@ -0,0 +1,22 @@
+import BorderDropHint from "../../nodeElement/borderDropHint";
+
+it("creates an element", () => {
+    const element = document.createElement("div");
+
+    const jqTreeElement = document.createElement("div");
+    jqTreeElement.classList.add("jqtree-element");
+    element.append(jqTreeElement);
+
+    new BorderDropHint(element, 0);
+
+    expect(jqTreeElement.children.length).toBe(1);
+    expect(jqTreeElement.children[0]).toHaveClass("jqtree-border");
+});
+
+it("doesn't create an element if the node doesn't have a jqtree-element child", () => {
+    const element = document.createElement("div");
+
+    new BorderDropHint(element, 0);
+
+    expect(element.children).toBeEmpty();
+});