Typescript Error: Constructor implementation is missing.ts(2390)

(alias) class Article
import Article

Constructor implementation is missing.ts(2390)

A parameter property is only allowed in a constructor implementation.ts(2369)

  export class ArticlesService {

    constructor(

      @Inject('xx')

      private articleRepository: Repository<Article>

    )

export class ArticlesService {

    constructor(

      @Inject('xx')

      private articleRepository: Repository<Article>

    ){}