feat(memoize): 重写实现，支持操作缓存

package.json

@@ -80,7 +80,6 @@
     "typescript": "^3.3.3333"
   },
   "dependencies": {
-    "fast-memoize": "^2.5.1",
     "is-chinese-phone-number": "^0.1.9"
   }
 }

src/memoize.ts

@@ -1,34 +1,83 @@
-import fastMemoize, { Options } from 'fast-memoize'
 import { AnyFunction } from './isFunction'
 
 export interface MemoizeOptions<T extends AnyFunction = AnyFunction> {
+  /**
+   * 创建缓存容器。
+   */
   createCache?(): {
+    /** 设置缓存 */
     set(key: string, value: any): void,
-    get(key: string): any,
+    /** 是否存在缓存 */
     has(key: string): boolean,
+    /** 获取缓存 */
+    get(key: string): any,
+    /** 删除缓存 */
+    delete(key: string): void,
+    /** 清空缓存 */
+    clear(): void,
   },
+  /**
+   * 序列化函数实参。
+   */
   serializer?(...args: Parameters<T>): string,
 }
 
+export type MemoizeReturn<T extends AnyFunction = AnyFunction> = T & {
+  /** 上一次执行函数时的缓存键名 */
+  lastCacheKey: string,
+  /** 缓存容器 */
+  cache: ReturnType<MemoizeOptions['createCache']>,
+}
+
 /**
  * 函数参数结果缓存。
  *
  * @param fn 要缓存的函数
  * @param [options] 选项
  * @returns 缓存化后的函数
  */
-export function memoize<T extends AnyFunction>(fn: T, options?: MemoizeOptions<T>): T {
-  let fastMemoizeOptions: Options<T> = undefined
-  if (options) {
-    fastMemoizeOptions = {}
-    if (options.createCache) {
-      fastMemoizeOptions.cache = {
-        create: options.createCache,
-      } as any
-    }
-    if (options.serializer) {
-      fastMemoizeOptions.serializer = args => options.serializer.apply(null, args as any)
+export function memoize<T extends AnyFunction>(
+  fn: T,
+  {
+    createCache = () => {
+      if (typeof Map === 'function' && Map.prototype.hasOwnProperty('clear')) {
+        return new Map()
+      }
+      const cache = Object.create(null)
+      return {
+        set(k, v) {
+          cache[k] = v
+        },
+        has(k) {
+          return (k in cache)
+        },
+        get(k) {
+          return cache[k]
+        },
+        delete(k) {
+          delete cache[k]
+        },
+        clear() {
+          Object.keys(cache).forEach(k => {
+            delete cache[k]
+          })
+        },
+      }
+    },
+    serializer = (...args) => {
+      return args.join(')`(')
+    },
+  }: MemoizeOptions<T> = {},
+): MemoizeReturn<T> {
+  const cache = createCache()
+  const memoizedFn: any = (...args: Parameters<T>) => {
+    const cacheKey = serializer(...args)
+    memoizedFn.lastCacheKey = cacheKey
+    if (!cache.has(cacheKey)) {
+      cache.set(cacheKey, fn(...args))
     }
+    return cache.get(cacheKey)
   }
-  return fastMemoize(fn, fastMemoizeOptions)
+  memoizedFn.cache = cache
+  return memoizedFn
 }

test/index.test.ts

@@ -1739,13 +1739,40 @@ describe('formatTemplate', () => {
 })
 
 describe('memoize', () => {
-  test('ok', () => {
-    const fn = jest.fn(() => 'ok')
-    const memoizedFn = vtils.memoize(fn)
+  const fn = jest.fn(() => 'ok')
+  const memoizedFn = vtils.memoize(fn)
+
+  test('调用原函数成功', () => {
     expect(memoizedFn()).toBe('ok')
+    expect(fn).toBeCalledTimes(1)
+  })
+
+  test('以同样的参数调用原函数将直接返回缓存的值', () => {
     expect(memoizedFn()).toBe('ok')
     expect(fn).toBeCalledTimes(1)
-    expect(memoizedFn('hello')).toBe('ok')
+  })
+
+  test('可以修改缓存', () => {
+    memoizedFn.cache.set(memoizedFn.lastCacheKey, 'hello')
+    expect(memoizedFn()).toBe('hello')
+    expect(fn).toBeCalledTimes(1)
+  })
+
+  test('可以获取缓存', () => {
+    expect(memoizedFn.cache.get(memoizedFn.lastCacheKey)).toBe('hello')
+  })
+
+  test('可以删除缓存', () => {
+    memoizedFn.cache.delete(memoizedFn.lastCacheKey)
+    expect(memoizedFn()).toBe('ok')
     expect(fn).toBeCalledTimes(2)
   })
+
+  test('可以清空缓存', () => {
+    expect(memoizedFn()).toBe('ok')
+    expect(fn).toBeCalledTimes(2)
+    memoizedFn.cache.clear()
+    expect(memoizedFn()).toBe('ok')
+    expect(fn).toBeCalledTimes(3)
+  })
 })

yarn.lock

@@ -2540,10 +2540,6 @@ fast-levenshtein@~2.0.4:
   version "2.0.6"
   resolved "https://registry.yarnpkg.com/fast-levenshtein/-/fast-levenshtein-2.0.6.tgz#3d8a5c66883a16a30ca8643e851f19baa7797917"
 
-fast-memoize@^2.5.1:
-  version "2.5.1"
-  resolved "https://registry.yarnpkg.com/fast-memoize/-/fast-memoize-2.5.1.tgz#c3519241e80552ce395e1a32dcdde8d1fd680f5d"
-
 fastparse@^1.1.1:
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/fastparse/-/fastparse-1.1.1.tgz#d1e2643b38a94d7583b479060e6c4affc94071f8"