feat: batchOfRequestOf 작성

packages/common/utils/src/batchOfRequestOf.test.ts

@@ -0,0 +1,62 @@
+import { describe, it, expect, vi } from 'vitest';
+import { batchRequestsOf } from './batchOfRequestOf';
+
+describe('batchRequestsOf에 대한 테스트 코드 작성', () => {
+  it('동일한 인자를 넣었을때 동일한 프로미스가 반환되어야 한다.', async () => {
+    const mockFunc = vi.fn((a: number, b: number) => {
+      return new Promise<number>((resolve) => {
+        setTimeout(() => resolve(a + b), 100);
+      });
+    });
+
+    const batchedFunc = batchRequestsOf(mockFunc);
+
+    const promise1 = batchedFunc(1, 2);
+    const promise2 = batchedFunc(1, 2);
+
+    expect(promise1).toBe(promise2);
+    expect(mockFunc).toHaveBeenCalledTimes(1);
+
+    const result = await promise1;
+    expect(result).toBe(3);
+  });
+
+  it('다른 인자를 넣었을때는 다른 프로미스가 반환 되어야 한다.', async () => {
+    const mockFunc = vi.fn((a: number, b: number) => {
+      return new Promise<number>((resolve) => {
+        setTimeout(() => resolve(a + b), 100);
+      });
+    });
+
+    const batchedFunc = batchRequestsOf(mockFunc);
+
+    const promise1 = batchedFunc(1, 2);
+    const promise2 = batchedFunc(3, 4);
+
+    expect(promise1).not.toBe(promise2);
+    expect(mockFunc).toHaveBeenCalledTimes(2);
+
+    const result1 = await promise1;
+    const result2 = await promise2;
+
+    expect(result1).toBe(3);
+    expect(result2).toBe(7);
+  });
+
+  it('프로미스가 resolve 된 후에는 새로운 프로미스가 반환 되어야 한다.', async () => {
+    const mockFunc = vi.fn((a: number, b: number) => {
+      return new Promise<number>((resolve) => {
+        setTimeout(() => resolve(a + b), 100);
+      });
+    });
+
+    const batchedFunc = batchRequestsOf(mockFunc);
+
+    const promise1 = batchedFunc(1, 2);
+    await promise1;
+
+    const promise2 = batchedFunc(1, 2);
+    expect(promise1).not.toBe(promise2);
+    expect(mockFunc).toHaveBeenCalledTimes(2);
+  });
+});

packages/common/utils/src/batchOfRequestOf.ts

@@ -0,0 +1,19 @@
+export function batchRequestsOf<F extends (...args: any[]) => any>(func: F) {
+  const promiseByKey = new Map<string, Promise<ReturnType<F>>>();
+
+  return function (...args: Parameters<F>) {
+    const key = JSON.stringify(args);
+
+    if (promiseByKey.has(key)) {
+      return promiseByKey.get(key)!;
+    } else {
+      const promise = func(...args);
+      promise.then(() => {
+        promiseByKey.delete(key);
+      });
+      promiseByKey.set(key, promise);
+
+      return promise;
+    }
+  } as F;
+}

packages/common/utils/src/index.ts

@@ -0,0 +1 @@
+export * from './batchOfRequestOf';