How to use the koa-convert.compose function in koa-convert

export default function middleware() {
    return convert.compose(
        logger(),
        bodyParser(),
        compress({
            filter: function (content_type) {
                if (/event-stream/i.test(content_type)) {
                    // 为了让hot reload生效，不对__webpack_hmr压缩
                    return false;
                } else {
                    return true;
                }
            },
        })
    );
}

import cros from './middleware/crosMiddleware'
import pipeMiddleware from './middleware/pipeMiddleware'

import routing from './routes/'
import { port, mongodb } from './config'

mongoose.connect(mongodb)
mongoose.connection.on('error', console.error)

const app = new Koa()

app.jsonSpaces = 0 // 压缩json返回中的空格
app.keys = ['key']

app.use(convert.compose(
  cros, // 跨域
  logger(),
  bodyParser(),
  session(app),
  pipeMiddleware()
))
// app.use(cros) // 跨域
// app.use(convert(logger()))
// app.use(convert(bodyParser()))
// app.use(convert(session(app)))
// app.use(pipeMiddleware())

routing(app)

app.listen(port, () => console.log(`✅ The server is running at http://localhost:${port}/`))

this.config.compress === false
                          ? this.config.compress
                          : true
                    })
                  )
                }
              }
              // use provided middleware
              if (this.config.middleware)
                for (
                  _b = 0, _c = this.config.middleware;
                  _b < _c.length;
                  _b++
                ) {
                  m = _c[_b]
                  this.app.use(KoaConvert.compose(m))
                }
              // use provided routers
              if (this.config.routers)
                for (_d = 0, _e = this.config.routers; _d < _e.length; _d++) {
                  r = _e[_d]
                  this.app.use(r.routes()).use(r.allowedMethods())
                }
              // 404 => SPA?
              if (this.config.spaFileRelativePath) {
                this.app.use(function(ctx) {
                  return __awaiter(_this, void 0, void 0, function() {
                    return __generator(this, function(_a) {
                      switch (_a.label) {
                        case 0:
                          if (!(ctx.status === 404)) return [3 /*break*/, 2]
                          return [

})

    app.use(errorMiddleware())
    app.use(bodyparser())
    app.use(json())

    app.use(httpMiddleware())
    app.use(authMiddleware())
    app.use(jsonSendMiddleware())

    app.use(koaMount(
        '/static', koaStatic(resolve(__dirname, '..', IS_DEV ? 'client/static' : 'client/dist/static')))
    )

    app.use(convert.compose(routes))
    app.use(convert.compose(allowedMethods))

    app.context.render = views(resolve(__dirname, '..', IS_DEV ? 'client' : 'client/dist'), {
        map: { html: 'swig' }
    })

    app.use(historyApiFallback({
        verbose: false,
        whiteList: ['/api'],
        rewrites: [
            {
                // connect-history-api-fallback 默认会对 url 中有 . 的 url 当成静态资源处理而不是当成页面地址来处理
                // from: /\d+\.\d+\.\d+\.\d+$/,
                from: /\/(\d+\.)*\d+$/,
                to: '/'
            },
            {

// 请求解析
app.use(
  convert(
    koaBody({
      multipart: true,
      formLimit: '5mb',
      formidable: {
        uploadDir: path.join(__dirname, '../tmp'),
      },
    }),
  ),
)

// middleware
app.use(
  convert.compose(
    stateMiddle(),
    authority(route.authRoutes), // 权限验证
    validation(), // 验证参数
    pipe(), // 通讯
  ),
)

// 静态文件
app.use(convert(koaStatic(path.join(__dirname, '../static'))))

// 渲染引擎
// app.use(views(path.join(__dirname, './static/theme/'), {
//   extension: 'ejs',
// }))

// 网络日志

)
      }
      if (this.config.json !== false) {
        this.app.use(
          KoaJson({
            pretty: this.config.jsonPretty || this.env === 'development',
            param: this.config.jsonPrettyParam || undefined,
            spaces: this.config.jsonSpaces || 2
          })
        )
      }

      // use provided middleware
      if (this.config.middleware)
        for (const m of this.config.middleware)
          this.app.use(KoaConvert.compose(m) as Koa.Middleware)

      // use provided routers
      if (this.config.routers)
        for (const r of this.config.routers)
          this.app.use(r.routes()).use(r.allowedMethods())

      // use provided public directories (with static cache)
      if (this.config.publicDirs) {
        for (const dir of this.config.publicDirs) {
          if (!this.config.cacheFiles) this.config.cacheFiles = {}
          const cacheFiles = { ...this.config.cacheFiles }
          for (const pathKey in cacheFiles) {
            if (!cacheFiles.hasOwnProperty(pathKey)) continue
            const value = cacheFiles[pathKey]
            delete cacheFiles[pathKey]
            // normalize paths

logger.error(err)
    })

    app.use(errorMiddleware())
    app.use(bodyparser())
    app.use(json())

    app.use(httpMiddleware())
    app.use(authMiddleware())
    app.use(jsonSendMiddleware())

    app.use(koaMount(
        '/static', koaStatic(resolve(__dirname, '..', IS_DEV ? 'client/static' : 'client/dist/static')))
    )

    app.use(convert.compose(routes))
    app.use(convert.compose(allowedMethods))

    app.context.render = views(resolve(__dirname, '..', IS_DEV ? 'client' : 'client/dist'), {
        map: { html: 'swig' }
    })

    app.use(historyApiFallback({
        verbose: false,
        whiteList: ['/api'],
        rewrites: [
            {
                // connect-history-api-fallback 默认会对 url 中有 . 的 url 当成静态资源处理而不是当成页面地址来处理
                // from: /\d+\.\d+\.\d+\.\d+$/,
                from: /\/(\d+\.)*\d+$/,
                to: '/'
            },

)
            }
            if (this.config.json !== false) {
              this.app.use(
                KoaJson({
                  pretty: this.config.jsonPretty || this.env === 'development',
                  param: this.config.jsonPrettyParam || undefined,
                  spaces: this.config.jsonSpaces || 2
                })
              )
            }
            // use provided middleware
            if (this.config.middleware)
              for (_i = 0, _a = this.config.middleware; _i < _a.length; _i++) {
                m = _a[_i]
                this.app.use(KoaConvert.compose(m))
              }
            // use provided routers
            if (this.config.routers)
              for (_b = 0, _c = this.config.routers; _b < _c.length; _b++) {
                r = _c[_b]
                this.app.use(r.routes()).use(r.allowedMethods())
              }
            // use provided public directories (with static cache)
            if (this.config.publicDirs) {
              _loop_1 = function(dir) {
                if (!this_1.config.cacheFiles) this_1.config.cacheFiles = {}
                var cacheFiles = __assign({}, this_1.config.cacheFiles)
                for (var pathKey in cacheFiles) {
                  if (!cacheFiles.hasOwnProperty(pathKey)) continue
                  var value = cacheFiles[pathKey]
                  delete cacheFiles[pathKey]

export default function api() {
    const router = new Router({
        prefix: config.app.baseApi,
    });
    Object.keys(routes).forEach(name => {
        return routes[name]['default'](router);
    });
    return convert.compose([
        router.routes(),
        router.allowedMethods(),
    ]);
}