test: cover glances widget internal modules

src/widgets/glances/components/custom_tooltip.test.jsx

@@ -0,0 +1,29 @@
+// @vitest-environment jsdom
+
+import { render, screen } from "@testing-library/react";
+import { describe, expect, it } from "vitest";
+
+import CustomTooltip from "./custom_tooltip";
+
+describe("widgets/glances/components/custom_tooltip", () => {
+  it("returns null when inactive", () => {
+    const { container } = render(<CustomTooltip active={false} payload={[]} formatter={(v) => String(v)} />);
+    expect(container.firstChild).toBeNull();
+  });
+
+  it("renders formatted values and series names when active", () => {
+    render(
+      <CustomTooltip
+        active
+        formatter={(v) => `v=${v}`}
+        payload={[
+          { value: 1, name: "A" },
+          { value: 2, name: "B" },
+        ]}
+      />,
+    );
+
+    expect(screen.getByText("v=1 A")).toBeInTheDocument();
+    expect(screen.getByText("v=2 B")).toBeInTheDocument();
+  });
+});