feat(utils): 新增 sampleBy, sampleIndex

src/date/index.ts

@@ -157,6 +157,7 @@ export {
   lastDayOfYear,
   lightFormat,
   max,
+  milliseconds,
   min,
   parse,
   parseISO,
@@ -235,6 +236,7 @@ export {
   enIN,
   enNZ,
   enUS,
+  enZA,
   eo,
   es,
   et,

src/utils/index.ts

@@ -59,6 +59,8 @@ export * from './readFile'
 export * from './RichUrl'
 export * from './rot13'
 export * from './run'
+export * from './sampleBy'
+export * from './sampleIndex'
 export * from './swap'
 export * from './traverse'
 export * from './TreeData'

src/utils/sampleBy.test.ts

@@ -0,0 +1,12 @@
+import { nthArg } from 'lodash-uni'
+import { sampleBy } from './sampleBy'
+
+describe('sampleBy', () => {
+  test('ok', () => {
+    expect(sampleBy([1, 2], (_, i) => i)).toBeOneOf([0, 1])
+    expect(sampleBy([1, 2], nthArg(1))).toBeOneOf([0, 1])
+    expect(sampleBy([], (_, i) => i)).toBeUndefined()
+    expect(sampleBy({ x: 1, y: 'dd' }, (_, k) => k)).toBeOneOf(['x', 'y'])
+    expect(sampleBy({}, (_, k) => k)).toBeUndefined()
+  })
+})

src/utils/sampleBy.ts

@@ -0,0 +1,26 @@
+import { forOwn, isArray, isObject, sample } from 'lodash-uni'
+
+/**
+ * 从集合中随机获得一个元素的迭代值。
+ *
+ * @param collection 集合
+ * @param iteratee 迭代函数
+ */
+export function sampleBy<T, X>(
+  collection: T[],
+  iteratee: (element: T, index: number) => X,
+): X | undefined
+export function sampleBy<T extends Record<any, any>, X>(
+  collection: T,
+  iteratee: <K extends keyof T>(value: T[K], key: K) => X,
+): X | undefined
+export function sampleBy(collection: any, iteratee: any): any {
+  if (isArray(collection)) {
+    return sample(collection.map(iteratee))
+  } else if (isObject(collection)) {
+    const values: any[] = []
+    forOwn(collection, (v, k) => values.push(iteratee(v, k)))
+    return sample(values)
+  }
+  return undefined
+}

src/utils/sampleIndex.test.ts

@@ -0,0 +1,10 @@
+import { sampleIndex } from './sampleIndex'
+
+describe('sampleIndex', () => {
+  test('ok', () => {
+    expect(sampleIndex([1, 2])).toBeOneOf([0, 1])
+    expect(sampleIndex([])).toBeUndefined()
+    expect(sampleIndex({ x: 1, y: 'o' })).toBeOneOf(['x', 'y'])
+    expect(sampleIndex({})).toBeUndefined()
+  })
+})

src/utils/sampleIndex.ts

@@ -0,0 +1,15 @@
+import { nthArg } from 'lodash-uni'
+import { sampleBy } from './sampleBy'
+
+/**
+ * 从集合中随机获得一个元素的索引（数组）或键（对象）。
+ *
+ * @param collection 集合
+ */
+export function sampleIndex<T>(collection: T[]): number | undefined
+export function sampleIndex<T extends Record<any, any>>(
+  collection: T,
+): keyof T | undefined
+export function sampleIndex(collection: any): any {
+  return sampleBy(collection, nthArg(1))
+}