window.ENTITIES={'/api/snippets/typescript/typescript%20-%20simple%20util%20that%20lets%20to%20use%20await%20multiple%20times%20and%20resolve%20them%20together%20by%20single%20call':[{"result":true,"message":null,"batch":{"type":"typescript","name":"typescript - simple util that lets to use await multiple times and resolve them together by single call","items":[{"id":"jPl4lj","type":"typescript","name":"TypeScript - simple util that lets to use await multiple times and resolve them together by single call","content":"type ResolveCallback<T extends unknown> = (result: T) => void;\ntype RejectCallback = (error?: any) => void;\n\nclass Locker<T extends unknown> {\n    private _promise: Promise<T> | null = null;\n    private _resolve: ResolveCallback<T> | null = null;\n    private _reject: RejectCallback | null = null;\n    private _state: 'result' | 'error' | null = null;\n    private _value: T | any | null = null;\n    /*\n     * Waits if `lock()` method was called until `resolve()` or `reject()` method is called.\n     */\n    public wait = async (): Promise<T> => {\n        if (this._promise) {\n            return await this._promise;\n        } else {\n            switch (this._state) {\n                case 'result':\n                    return this._value as T;\n                case 'error':\n                    throw this._value;\n                default:\n                    throw new Error('Locker has unknown state.');\n            }\n        }\n    };\n    /*\n     * Locks state by that may be unlocked by `resolve()` or `reject()` method call.\n     */\n    public lock = (): boolean => {\n        if (this._promise) {\n            return false;\n        }\n        const executor = (resolve: ResolveCallback<T>, reject: RejectCallback): void => {\n            this._resolve = resolve;\n            this._reject = reject;\n        };\n        this._promise = new Promise(executor);\n        return true;\n    };\n    /*\n     * Unlocks the call to the `wait()` method and returns the result from it.\n     */\n    public resolve = (result: T): void => {\n        if (this._promise) {\n            this._promise = null;\n            this._state = 'result';\n            this._value = result;\n            return this._resolve!(result);\n        } else {\n            throw new Error('Locker is not locked.');\n        }\n    };\n    /*\n     * Unlocks the call to the `wait()` method and throws the error from it.\n     */\n    public reject = (error?: any): void => {\n        if (this._promise) {\n            this._promise = null;\n            this._state = 'error';\n            this._value = error;\n            return this._reject!(error);\n        } else {\n            throw new Error('Locker is not locked.');\n        }\n    };\n}\n\n\n\n// Usage example:\n\nconst locker = new Locker();\n\nconst method = async (): Promise<void> => {\n    console.log(`Method called!`);\n    try {\n        const result = await locker.wait();\n        console.log(`Method unlocked! Message: ${result}`);\n    } catch (error) {\n        console.error(`Method unlocked! Error: ${error}`);\n    }\n};\n\nlocker.lock();  // <------------------------------------------------- blocks `locker.wait()` call\n\nmethod();\nmethod();\nmethod();\n\nsetTimeout((): void => locker.resolve('Job done!'), 1000);  // <----- resolves `locker.wait()` call after 1 second","source":"","author":{"id":"r0ePGo","name":"Mahir-Bright","avatar":"1629142857766__r0ePGo__w40px_h40px.jpg","points":1341,"role":"BASIC"},"creationTime":1707143811000,"updateTime":1707211074000,"removalTime":null}]}}]};