test(bezier-react): Improved array test coverage

packages/bezier-react/src/utils/array.test.ts

@@ -1,20 +1,37 @@
 import {
   compact,
   flattenDeep,
+  isLastIndex,
 } from './array'
 
-describe('arrayUtils', () => {
-  describe('compact', () => {
-    it('should remove falsy item', () => {
-      const array = [0, 1, false, 2, '', 3]
-      expect(compact(array)).toEqual([1, 2, 3])
-    })
+describe('isLastIndex', () => {
+  it('should return true when the last array index', () => {
+    const arr = [0, 1, 2, 3, 4]
+
+    const result = isLastIndex(arr, 4)
+
+    expect(result).toBe(true)
+  })
+
+  it('should return false when not the last array index', () => {
+    const arr = [0, 1, 2, 3, 4]
+
+    const result = isLastIndex(arr, 1)
+
+    expect(result).toBe(false)
   })
+})
+
+describe('compact', () => {
+  it('should remove falsy item', () => {
+    const array = [0, 1, false, 2, '', 3]
+    expect(compact(array)).toEqual([1, 2, 3])
+  })
+})
 
-  describe('flattenDeep', () => {
-    it('should return flatten array', () => {
-      const array = [1, [2, [3, [4]], 5]]
-      expect(flattenDeep(array)).toEqual([1, 2, 3, 4, 5])
-    })
+describe('flattenDeep', () => {
+  it('should return flatten array', () => {
+    const array = [1, [2, [3, [4]], 5]]
+    expect(flattenDeep(array)).toEqual([1, 2, 3, 4, 5])
   })
 })

packages/bezier-react/src/utils/array.ts

@@ -1,6 +1,6 @@
 import { isArray } from './type'
 
-export function isLastIndex(array: any[], index: number) {
+export function isLastIndex(array: ArrayLike<unknown>, index: number) {
   return array.length - 1 === index
 }