fix(mutex): remove internal state

Author: format-x

package.json

@@ -1,6 +1,6 @@
 {
   "name": "redis-sp",
-  "version": "1.0.2",
+  "version": "1.1.2",
   "description": "Redis synchronization primitives based on redlock algorithm",
   "main": "./dist/index.js",
   "types": "./dist/index.d.ts",

src/mutex.ts

@@ -42,48 +42,28 @@ export default class RedisMutexImpl implements Mutex {
   }
 
   public async lock(options?: LockOptions): Promise<void> {
-    if (this.isLocked) {
-      throw new Error('Already locked');
-    }
-
     await withRetries(async () => {
-      this.isLocked = true;
-
       try {
         await this.tryToAcquireLock();
       } catch {
         await this.tryToReleaseLock();
 
-        this.isLocked = false;
-
         throw withRetries.RETRY_SYMBOL;
       }
     }, options?.retryOptions || this.retryOptions)();
   }
 
   public async tryToLock(): Promise<boolean> {
-    if (this.isLocked) {
-      throw new Error('Already locked');
-    }
-
-    this.isLocked = true;
-
     try {
       await this.tryToAcquireLock();
     } catch {
-      this.isLocked = false;
+      return false;
     }
 
-    return this.isLocked;
+    return true;
   }
 
   public async unlock(): Promise<void> {
-    if (!this.isLocked) {
-      throw new Error('Not locked');
-    }
-
-    this.isLocked = false;
-
     await waitForFirstN(
       this.clients,
       async (client) => {
@@ -135,8 +115,6 @@ export default class RedisMutexImpl implements Mutex {
     );
   }
 
-  private isLocked = false;
-
   private readonly expireAfterMillis: number;
   private readonly retryOptions: WithRetriesOptions;
   private readonly resourceId: string;

test/mutex.test.ts

@@ -118,53 +118,6 @@ describe('mutex negative test cases. incorrect usage', () => {
     jest.resetAllMocks();
   });
 
-  it('should throw an exception if you try to call `tryToLock` method on a locked mutex', async () => {
-    const resourceId = '3dd6472f-4e4b-4559-b781-cc5d75c4f6f2';
-
-    const client = createRedisClientStub();
-
-    asMockedFunction(Lua.tryToAcquireLock).mockResolvedValueOnce('OK');
-
-    const mutex = new RedisMutex([client], resourceId);
-
-    await mutex.lock();
-
-    await expect(mutex.tryToLock()).rejects.toThrowError(new Error('Already locked'));
-
-    expect(Lua.tryToAcquireLock).toBeCalledTimes(1);
-    expect(Lua.tryToReleaseLock).toBeCalledTimes(0);
-  });
-
-  it('should throw an exception if you try to call `lock` method on a locked mutex', async () => {
-    const resourceId = '3dd6472f-4e4b-4559-b781-cc5d75c4f6f2';
-
-    const client = createRedisClientStub();
-
-    asMockedFunction(Lua.tryToAcquireLock).mockResolvedValueOnce('OK');
-
-    const mutex = new RedisMutex([client], resourceId);
-
-    await mutex.lock();
-
-    await expect(mutex.lock()).rejects.toThrowError(new Error('Already locked'));
-
-    expect(Lua.tryToAcquireLock).toBeCalledTimes(1);
-    expect(Lua.tryToReleaseLock).toBeCalledTimes(0);
-  });
-
-  it('should throw an exception if you try to call `unlock` method on a unlocked mutex', async () => {
-    const resourceId = '3dd6472f-4e4b-4559-b781-cc5d75c4f6f2';
-
-    const client = createRedisClientStub();
-
-    const mutex = new RedisMutex([client], resourceId);
-
-    await expect(mutex.unlock()).rejects.toThrowError(new Error('Not locked'));
-
-    expect(Lua.tryToAcquireLock).toBeCalledTimes(0);
-    expect(Lua.tryToReleaseLock).toBeCalledTimes(0);
-  });
-
   it('should throw an exception on failed quorum', async () => {
     const resourceId = '3dd6472f-4e4b-4559-b781-cc5d75c4f6f2';
     const options = {