feat: 新增 defaultTo

src/defaultTo.test.ts

@@ -0,0 +1,16 @@
+import { defaultTo } from './defaultTo'
+import { jestExpectEqual } from './enhanceJest'
+
+test('表现正常', () => {
+  jestExpectEqual(
+    defaultTo(1, 2),
+    1,
+  )
+
+  ;[NaN, null, undefined].forEach(item => {
+    jestExpectEqual(
+      defaultTo(item, 2),
+      2,
+    )
+  })
+})

src/defaultTo.ts

@@ -0,0 +1,19 @@
+import { isNaN, isNil } from './is'
+
+/**
+ * 检查 `value` 是否是 `null`、`undefined`、`NaN`，是则返回 `defaultValue`，否则返回 `value`。
+ *
+ * @param value 要检查的值
+ * @param defaultValue 默认值
+ * @returns 返回结果值
+ * @example
+ * ```ts
+ * defaultTo(1, 2) // => 1
+ * defaultTo(NaN, 2) // => 2
+ * defaultTo(null, 2) // => 2
+ * defaultTo(undefined, 2) // => 2
+ * ```
+ */
+export function defaultTo<T>(value: T, defaultValue: T): T {
+  return isNil(value) || isNaN(value) ? defaultValue : value
+}

src/index.ts

@@ -5,6 +5,7 @@ export * from './castArray'
 export * from './chunk'
 export * from './clamp'
 export * from './debounce'
+export * from './defaultTo'
 export * from './Disposer'
 export * from './EasyStorage'
 export * from './EasyValidator'