LockManager.ts

export interface LockManager {
  lock(fn: () => Promise<void>): Promise<void>
}

/**
 * This is my limited implementation of Locks manager for browsers.
 * I implemented my own because this technology is experimental yet.
 * @see https://developer.mozilla.org/en-US/docs/Web/API/LockManager
 */
export class NaiveLockManager implements LockManager {
  private locked = false
  private waitList: Array<(error?: Error) => void> = []

  async lock(fn: () => Promise<void>): Promise<void> {
    if (this.locked) {
      // this.loggerService.info("Sensitive operation already in progress. Waiting for finish.", {
      //   lockId: this.lockId,
      // })
      return new Promise((resolve, reject) => {
        this.waitList.push(error => (error ? reject(error) : resolve()))
      })
    }

    this.locked = true
    // this.loggerService.info("Performing sensitive operation.", {
    //   lockId: this.lockId,
    // })
    try {
      await fn()
      // this.loggerService.info("Sensitive operation finished.", {
      //   lockId: this.lockId,
      //   waitListSize: this.waitList.length,
      // })
      this.waitList.forEach(cb => cb())
    } catch (error) {
      // this.loggerService.error("Sensitive operation failed.", {
      //   error,
      //   lockId: this.lockId,
      //   waitListSize: this.waitList.length,
      // })
      this.waitList.forEach(cb => cb(error))
    } finally {
      this.waitList = []
      this.locked = false
    }
  }
}

export function createLockManager(): LockManager {
  return new NaiveLockManager()
}