Decorator pattern example in Typescript

decorators.ts

// decorator example

export interface IWork {
  doWork (work: any): void
}

export class ImportantService implements IWork { 
  doWork (work: any): void {
    // important work done here
  }
}

export class MyAuditor implements IWork {

  serviceToAudit: IWork

  constructor (serviceToAudit: IWork) {
    this.serviceToAudit = serviceToAudit
  }

  doWork (work: any): void {
    this.audit(work)
    this.serviceToAudit.doWork(work)
  }
  private audit (something: any) {
    // do some auditing
    console.log(something)
  }
}

export class RetryService implements IWork {
  private maxRetries = 3
  private serviceToRetry: IWork
  constructor (serviceToRetry: IWork) {
    this.serviceToRetry = serviceToRetry
  }

  private tryWork (work: any) {
    this.serviceToRetry.doWork(work)
  }

  doWork (work: any): void {
    var tries = 0
    try {
      this.tryWork(work)
    } catch (error) {
      tries++
       if (tries < this.maxRetries)
        {
          this.tryWork(work)
        } else {
          throw error
        }
    }
  }
}

const resolveImportantService = () => {
  const importantService = new ImportantService()
  const retrier = new RetryService(importantService)
  const auditor = new MyAuditor(retrier)
  return auditor
}

function myClientCode () {
  const service = resolveImportantService()
  service.doWork('some work to do')
}