feat(packages/stdlib): add execute method for SyncMutex

packages/stdlib/src/sync/mutex/index.test.ts

@@ -1,4 +1,4 @@
-import { describe, it, expect, beforeEach } from 'vitest';
+import { describe, it, expect, beforeEach, vi } from 'vitest';
 import { SyncMutex } from '.';
 
 describe('SyncMutex', () => {
@@ -14,24 +14,28 @@ describe('SyncMutex', () => {
 
   it('lock the mutex', () => {
     mutex.lock();
+  
     expect(mutex.isLocked).toBe(true);
   });
 
   it('remain locked when locked multiple times', () => {
     mutex.lock();
     mutex.lock();
+  
     expect(mutex.isLocked).toBe(true);
   });
 
   it('unlock a locked mutex', () => {
     mutex.lock();
     mutex.unlock();
+  
     expect(mutex.isLocked).toBe(false);
   });
 
   it('remain unlocked when unlocked multiple times', () => {
     mutex.unlock();
     mutex.unlock();
+
     expect(mutex.isLocked).toBe(false);
   });
 
@@ -42,4 +46,49 @@ describe('SyncMutex', () => {
     mutex.unlock();
     expect(mutex.isLocked).toBe(false);
   });
+
+  it('execute a callback when unlocked', async () => {
+    const callback = vi.fn(() => 'done');
+    const result = await mutex.execute(callback);
+  
+    expect(result).toBe('done');
+    expect(callback).toHaveBeenCalled();
+  });
+
+  it('execute a promise callback when unlocked', async () => {
+    const callback = vi.fn(() => Promise.resolve('done'));
+    const result = await mutex.execute(callback);
+  
+    expect(result).toBe('done');
+    expect(callback).toHaveBeenCalled();
+  });
+
+  it('execute concurrent callbacks only one at a time', async () => {
+    const callback = vi.fn(() => Promise.resolve('done'));
+
+    const result = await Promise.all([
+      mutex.execute(callback),
+      mutex.execute(callback),
+      mutex.execute(callback),
+    ]);
+  
+    expect(result).toEqual(['done', undefined, undefined]);
+    expect(callback).toHaveBeenCalledTimes(1);
+  });
+
+  it('does not execute a callback when locked', async () => {
+    const callback = vi.fn(() => 'done');
+    mutex.lock();
+    const result = await mutex.execute(callback);
+
+    expect(result).toBeUndefined();
+    expect(callback).not.toHaveBeenCalled();
+  });
+
+  it('unlocks after executing a callback', async () => {
+    const callback = vi.fn(() => 'done');
+    await mutex.execute(callback);
+  
+    expect(mutex.isLocked).toBe(false);
+  });
 });

packages/stdlib/src/sync/mutex/index.ts

@@ -1,3 +1,5 @@
+import type { MaybePromise } from "../../types";
+
 /**
  * @name SyncMutex
  * @category Utils
@@ -10,10 +12,15 @@
  *
  * mutex.unlock();
  * 
+ * const result = await mutex.execute(() => {
+ *  // do something
+ *  return Promise.resolve('done');  
+ * });
+ * 
  * @since 0.0.5
  */
 export class SyncMutex {
-  private state: boolean = false;
+  private state = false;
 
   public get isLocked() {
     return this.state;
@@ -26,4 +33,15 @@ export class SyncMutex {
   public unlock() {
     this.state = false;
   }
+
+  public async execute<T>(callback: () => T) {
+    if (this.isLocked)
+      return;
+
+    this.lock();
+    const result = await callback();
+    this.unlock();
+
+    return result;
+  }
 }