feat(utils): 新增 defaultIndexTo 设置索引的默认值

src/utils/defaultIndexTo.test.ts

@@ -0,0 +1,13 @@
+import { defaultIndexTo } from './defaultIndexTo'
+
+describe('defaultIndexTo', () => {
+  test('ok', () => {
+    expect(defaultIndexTo(-1, 1)).toBe(1)
+    expect(defaultIndexTo(-1, 0)).toBe(0)
+    expect(defaultIndexTo(-2, 0)).toBe(0)
+    expect(defaultIndexTo(NaN, 1)).toBe(1)
+    expect(defaultIndexTo(NaN, 0)).toBe(0)
+    expect(defaultIndexTo(1, 0)).toBe(1)
+    expect(defaultIndexTo(2, 1)).toBe(2)
+  })
+})

src/utils/defaultIndexTo.ts

@@ -0,0 +1,9 @@
+/**
+ * 设置默认索引。当前索引为 `-1` 或 `NaN` 时会使用默认索引。
+ *
+ * @param index 当前索引
+ * @param defaultIndex 默认索引
+ */
+export function defaultIndexTo(index: number, defaultIndex: number): number {
+  return index < 0 || index !== index ? defaultIndex : index
+}

src/utils/index.ts

@@ -19,6 +19,7 @@ export * from './createSubmit'
 export * from './createUrlQueryString'
 export * from './DataPacker'
 export * from './dedent'
+export * from './defaultIndexTo'
 export * from './EventBus'
 export * from './formatBytes'
 export * from './formatNumber'