Provide migration guide for setupMiddlewares

[oobles]

Documentation Is:

• [x ] Missing
• [x ] Needed
• Confusing
• Not Sure?

Please Explain in Detail...

The recent change for issue #4068 deprecates onAfterSetupMiddleware and onBeforeSetupMiddleware. The commit making the change provides a new example, but there's no migration guide on how to migrate away from the deprecated configuration options.

Your Proposal for Changes

[snitin315]

Before

module.exports = {
  //...
  devServer: {
    onAfterSetupMiddleware: function (devServer) {
      if (!devServer) {
        throw new Error('webpack-dev-server is not defined');
      }

      devServer.app.get('/some/after/path', function (req, res) {
        res.json({ custom: 'response-after' });
      });
    },

    onBeforeSetupMiddleware: function (devServer) {
      if (!devServer) {
        throw new Error('webpack-dev-server is not defined');
      }

      devServer.app.get('/some/before/path', function (req, res) {
        res.json({ custom: 'response-before' });
      });
    },
  },
};

After

module.exports = {
  // ...
  devServer: {
    setupMiddlewares: (middlewares, devServer) => {
      if (!devServer) {
        throw new Error('webpack-dev-server is not defined');
      }

       // onBeforeSetupMiddleware
      devServer.app.get('/some/before/path', (_, response) => {
         response.json({ custom: 'response-before' });
      });

      // onAfterSetupMiddleware
      middlewares.push({
        name: 'after-middleware',
        // `path` is optional
        path: '/some/after/path',
        middleware: (req, res) => {
          res.json({ custom: 'response-after' });
        },
      });

      // another after middleware
      middlewares.push((req, res) => {
        res.send('Hello World!');
      });

      return middlewares;
    },
  },
};

I believe this should be the migration. /cc @alexander-akait

[markcipolla]

Thanks @snitin315 🙏🏻

How would you migrate a before and after block with server.use instead of server.get?
e.g. the below:

before(app, server) {
      // Keep `evalSourceMapMiddleware` and `errorOverlayMiddleware`
      // middlewares before `redirectServedPath` otherwise will not have any effect
      // This lets us fetch source contents from webpack for the error overlay
      app.use(evalSourceMapMiddleware(server));
      // This lets us open files from the runtime error overlay.
      app.use(errorOverlayMiddleware());

      if (fs.existsSync(paths.proxySetup)) {
        // This registers user provided middleware for proxy reasons
        require(paths.proxySetup)(app);
      }
    },
    after(app) {
      // Redirect to `PUBLIC_URL` or `homepage` from `package.json` if url not match
      app.use(redirectServedPath(paths.publicUrlOrPath));

      // This service worker file is effectively a 'no-op' that will reset any
      // previous service worker registered for the same host:port combination.
      // We do this in development to avoid hitting the production cache if
      // it used the same host and port.
      // https://github.com/facebook/create-react-app/issues/2272#issuecomment-302832432
      app.use(noopServiceWorkerMiddleware(paths.publicUrlOrPath));
    },

[alexander-akait]

middlewares is just array, put it before or after, as you work with arrays and return modified array

[otakustay]

Note that app.get(...) in onAfterSetupMiddleware is not the same as app.get(...) in setupMiddlewares.

It seems app.get() in setupMiddlewares are always applied before middlewares are applied, if we have a config like this:

{
    onAfterSetupMiddleware: server => {
        server.app.get('/__index__.html', (req, res) => res.send('foo'));
    },
    config.historyApiFallback = {
        index: '/__index__.html',
        disableDotRule: true,
    };
}

The route /__index__.html will take place for history api fallback, however if we changed it to this:

{
    setupMiddlewares: (middlewares, server) => {
        server.app.get('/__index__.html', (req, res) => res.send('foo'));
        return middlewares;
    },
    config.historyApiFallback = {
        index: '/__index__.html',
        disableDotRule: true,
    };
}

History api fallback are broken, we have to transform it into a middleware like:

middlewares.unshift({
    path: '/__index__.html',
    handler: (req, res, next) => {
        if (req.method === 'GET') {
            res.send('foo');
        }
        else {
            next();
        }
    }
});

In this way we have to add a request.method check in middleware implementation.

[alexander-akait]

Yes, it is good solution 👍

[coderXaj]

(node:9304) [DEP_WEBPACK_DEV_SERVER_ON_AFTER_SETUP_MIDDLEWARE] DeprecationWarning: 'onAfterSetupMiddleware' option is deprecated. Please use the 'setupMiddlewares' option.
(Use node --trace-deprecation ... to show where the warning was created)
(node:9304) [DEP_WEBPACK_DEV_SERVER_ON_BEFORE_SETUP_MIDDLEWARE] DeprecationWarning: 'onBeforeSetupMiddleware' option is deprecated. Please use the 'setupMiddlewares' option.

Can any one please tell me how solve to this error my localhost is not opening after i get this error.

[umair39]

Before

module.exports = {
  //...
  devServer: {
    onAfterSetupMiddleware: function (devServer) {
      if (!devServer) {
        throw new Error('webpack-dev-server is not defined');
      }

      devServer.app.get('/some/after/path', function (req, res) {
        res.json({ custom: 'response-after' });
      });
    },

    onBeforeSetupMiddleware: function (devServer) {
      if (!devServer) {
        throw new Error('webpack-dev-server is not defined');
      }

      devServer.app.get('/some/before/path', function (req, res) {
        res.json({ custom: 'response-before' });
      });
    },
  },
};

After

module.exports = {
  // ...
  devServer: {
    setupMiddlewares: (middlewares, devServer) => {
      if (!devServer) {
        throw new Error('webpack-dev-server is not defined');
      }

       // onBeforeSetupMiddleware
      devServer.app.get('/some/before/path', (_, response) => {
         response.json({ custom: 'response-before' });
      });

      // onAfterSetupMiddleware
      middlewares.push({
        name: 'after-middleware',
        // `path` is optional
        path: '/some/after/path',
        middleware: (req, res) => {
          res.json({ custom: 'response-after' });
        },
      });

      // another after middleware
      middlewares.push((req, res) => {
        res.send('Hello World!');
      });

      return middlewares;
    },
  },
};

I believe this should be the migration. /cc @alexander-akait

i am facing same issue how i use that code in node module files

[umair39]

where i can find file to isert modified code

[alexander-akait]

webpack.config.js file

[darkcohiba]

@snitin315 I can not find where to replace the code with the updated segment, what is the module this goes in?

[snitin315]

@darkcohiba inside webpack.config.js, devServer option to be specific.

[darkcohiba]

@snitin315 this is my webpack config js dev server, I don't see what I need to replace;

`// @remove-on-eject-begin
/**

• Copyright (c) 2015-present, Facebook, Inc.
• This source code is licensed under the MIT license found in the
• LICENSE file in the root directory of this source tree.
  */
  // @remove-on-eject-end
  'use strict';

const fs = require('fs');
const evalSourceMapMiddleware = require('react-dev-utils/evalSourceMapMiddleware');
const noopServiceWorkerMiddleware = require('react-dev-utils/noopServiceWorkerMiddleware');
const ignoredFiles = require('react-dev-utils/ignoredFiles');
const redirectServedPath = require('react-dev-utils/redirectServedPathMiddleware');
const paths = require('./paths');
const getHttpsConfig = require('./getHttpsConfig');

const host = process.env.HOST || '0.0.0.0';
const sockHost = process.env.WDS_SOCKET_HOST;
const sockPath = process.env.WDS_SOCKET_PATH; // default: '/ws'
const sockPort = process.env.WDS_SOCKET_PORT;

module.exports = function (proxy, allowedHost) {
const disableFirewall =
!proxy || process.env.DANGEROUSLY_DISABLE_HOST_CHECK === 'true';
return {
// WebpackDevServer 2.4.3 introduced a security fix that prevents remote
// websites from potentially accessing local content through DNS rebinding:
// #887
// https://medium.com/webpack/webpack-dev-server-middleware-security-issues-1489d950874a
// However, it made several existing use cases such as development in cloud
// environment or subdomains in development significantly more complicated:
// facebook/create-react-app#2271
// facebook/create-react-app#2233
// While we're investigating better solutions, for now we will take a
// compromise. Since our WDS configuration only serves files in the public
// folder we won't consider accessing them a vulnerability. However, if you
// use the proxy feature, it gets more dangerous because it can expose
// remote code execution vulnerabilities in backends like Django and Rails.
// So we will disable the host check normally, but enable it if you have
// specified the proxy setting. Finally, we let you override it if you
// really know what you're doing with a special environment variable.
// Note: ["localhost", ".localhost"] will support subdomains - but we might
// want to allow setting the allowedHosts manually for more complex setups
allowedHosts: disableFirewall ? 'all' : [allowedHost],
headers: {
'Access-Control-Allow-Origin': '',
'Access-Control-Allow-Methods': '',
'Access-Control-Allow-Headers': '*',
},
// Enable gzip compression of generated files.
compress: true,
static: {
// By default WebpackDevServer serves physical files from current directory
// in addition to all the virtual build products that it serves from memory.
// This is confusing because those files won’t automatically be available in
// production build folder unless we copy them. However, copying the whole
// project directory is dangerous because we may expose sensitive files.
// Instead, we establish a convention that only files in public directory
// get served. Our build script will copy public into the build folder.
// In index.html, you can get URL of public folder with %PUBLIC_URL%:
//
// In JavaScript code, you can access it with process.env.PUBLIC_URL.
// Note that we only recommend to use public folder as an escape hatch
// for files like favicon.ico, manifest.json, and libraries that are
// for some reason broken when imported through webpack. If you just want to
// use an image, put it in src and import it from JavaScript instead.
directory: paths.appPublic,
publicPath: [paths.publicUrlOrPath],
// By default files from contentBase will not trigger a page reload.
watch: {
// Reportedly, this avoids CPU overload on some systems.
// facebook/create-react-app#293
// src/node_modules is not ignored to support absolute imports
// facebook/create-react-app#1065
ignored: ignoredFiles(paths.appSrc),
},
},
client: {
webSocketURL: {
// Enable custom sockjs pathname for websocket connection to hot reloading server.
// Enable custom sockjs hostname, pathname and port for websocket connection
// to hot reloading server.
hostname: sockHost,
pathname: sockPath,
port: sockPort,
},
overlay: {
errors: true,
warnings: false,
},
},
devMiddleware: {
// It is important to tell WebpackDevServer to use the same "publicPath" path as
// we specified in the webpack config. When homepage is '.', default to serving
// from the root.
// remove last slash so user can land on /test instead of /test/
publicPath: paths.publicUrlOrPath.slice(0, -1),
},

https: getHttpsConfig(),
host,
historyApiFallback: {
  // Paths with dots should still use the history fallback.
  // See https://github.com/facebook/create-react-app/issues/387.
  disableDotRule: true,
  index: paths.publicUrlOrPath,
},
// `proxy` is run between `before` and `after` `webpack-dev-server` hooks
proxy,
onBeforeSetupMiddleware(devServer) {
  // Keep `evalSourceMapMiddleware`
  // middlewares before `redirectServedPath` otherwise will not have any effect
  // This lets us fetch source contents from webpack for the error overlay
  devServer.app.use(evalSourceMapMiddleware(devServer));

  if (fs.existsSync(paths.proxySetup)) {
    // This registers user provided middleware for proxy reasons
    require(paths.proxySetup)(devServer.app);
  }
},
onAfterSetupMiddleware(devServer) {
  // Redirect to `PUBLIC_URL` or `homepage` from `package.json` if url not match
  devServer.app.use(redirectServedPath(paths.publicUrlOrPath));

  // This service worker file is effectively a 'no-op' that will reset any
  // previous service worker registered for the same host:port combination.
  // We do this in development to avoid hitting the production cache if
  // it used the same host and port.
  // https://github.com/facebook/create-react-app/issues/2272#issuecomment-302832432
  devServer.app.use(noopServiceWorkerMiddleware(paths.publicUrlOrPath));
},

};
};
`

[alielachkar]

@snitin315 I don't think the question to migrate onBeforeSetupMiddleware with use instead of get has been answered. How would migrate something like this?

 onBeforeSetupMiddleware: function (devServer) {
            devServer.app.use(function(req, res, next) {
                res.setHeader('Access-Control-Allow-Origin', '*');
                res.setHeader('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE');
                res.setHeader('Access-Control-Allow-Headers', 'Content-Type, Authorization');
                next();
            });
        }
},

I tried using unshift as mentioned in the DevServer documentation, but without success.

[alielachkar]

FIgured it out! return wasn't necessary in onBeforeSetupMiddleware, but it is with setupMiddlewares

        setupMiddlewares: function (middlewares) {
            middlewares.unshift(function(req, res, next) {
                res.setHeader('Access-Control-Allow-Origin', '*');
                res.setHeader('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE');
                res.setHeader('Access-Control-Allow-Headers', 'Content-Type, Authorization');
                next();
            });
            return middlewares;
        },