Improve code coverage for cli package (#13724)

packages/cli/src/utils/math.test.ts

@@ -0,0 +1,24 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect } from 'vitest';
+import { lerp } from './math.js';
+
+describe('math', () => {
+  describe('lerp', () => {
+    it.each([
+      [0, 10, 0, 0],
+      [0, 10, 1, 10],
+      [0, 10, 0.5, 5],
+      [10, 20, 0.5, 15],
+      [-10, 10, 0.5, 0],
+      [0, 10, 2, 20],
+      [0, 10, -1, -10],
+    ])('lerp(%d, %d, %d) should return %d', (start, end, t, expected) => {
+      expect(lerp(start, end, t)).toBe(expected);
+    });
+  });
+});