vuepress dev: throws res.getHeader() is not a function

• I confirm that this is an issue rather than a question.

Bug report

• Related issue: https://github.com/webpack/webpack-dev-middleware/issues/380
• PR fix: https://github.com/shellscape/koa-webpack/pull/110

Version

• vuepress@0.14.10
• Reproduce same fault with node v10.9.0 AND node v8.11.4
• Windows 10

Steps to reproduce

NOTE: This was a first time use of vuepress.

$ npm i -g vuepress
$ echo "# Some Stuff" >> README.md
$ vuepress dev

> VuePress dev server listening at http://localhost:8080/

Visit http://localhost:8080/ in browser

Server throws …

(node:14508) UnhandledPromiseRejectionWarning: TypeError: res.getHeader is not a function
    at processRequest (C:\ProgramData\nvm\v10.9.0\node_modules\vuepress\node_modules\webpack-dev-middleware\lib\middleware.js:82:18)
    at ready (C:\ProgramData\nvm\v10.9.0\node_modules\vuepress\node_modules\webpack-dev-middleware\lib\util.js:51:12)
    at handleRequest (C:\ProgramData\nvm\v10.9.0\node_modules\vuepress\node_modules\webpack-dev-middleware\lib\util.js:167:5)
    at Promise (C:\ProgramData\nvm\v10.9.0\node_modules\vuepress\node_modules\webpack-dev-middleware\lib\middleware.js:44:7)
    at new Promise (<anonymous>)
    at middleware (C:\ProgramData\nvm\v10.9.0\node_modules\vuepress\node_modules\webpack-dev-middleware\lib\middleware.js:43:12)
    at Promise.all.Promise (C:\ProgramData\nvm\v10.9.0\node_modules\vuepress\node_modules\koa-webpack\index.js:43:7)
    at new Promise (<anonymous>)
    at C:\ProgramData\nvm\v10.9.0\node_modules\vuepress\node_modules\koa-webpack\index.js:42:5
    at dispatch (C:\ProgramData\nvm\v10.9.0\node_modules\vuepress\node_modules\koa\node_modules\koa-compose\index.js:42:32)
    at C:\ProgramData\nvm\v10.9.0\node_modules\vuepress\node_modules\@shellscape\koa-static\legacy\index.js:58:19
    at Generator.throw (<anonymous>)
    at step (C:\ProgramData\nvm\v10.9.0\node_modules\vuepress\node_modules\@shellscape\koa-static\legacy\index.js:6:221)
    at _throw (C:\ProgramData\nvm\v10.9.0\node_modules\vuepress\node_modules\@shellscape\koa-static\legacy\index.js:6:455)
(node:14508) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:14508) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

[ulivz]

The dependency chain is webpack-serve -> koa-webpack -> webpack-dev-middleware, and it’s caused by the underlying webpack-dev-middleware@3.6.1, so If you’re a yarn user you can use resolutions for a temporary fix:

  "resolutions": {
    "webpack-dev-middleware": "3.6.0"
  }

While the npm user can re-install webpack-dev-middleware with a specific version:

npm install webpack-dev-middleware@3.6.0

When webpack-dev-middleware fixes the issue and publishes, the issue can be closed.

[abrahamdio]

@edadams Sorry if my answer confused you, I didn’t have so much time at that point to dig down which dependency is the culprit.

Since @ulivz has found the exact module that caused the issue, you can override that module version in your package.json, you can read more about the yarn’s resolution docs here, https://yarnpkg.com/lang/en/docs/selective-version-resolutions/

What you want to do is to edit your package.json file, and add,

  "resolutions": {
    "webpack-dev-middleware": "3.6.0"
  }

And run yarn install again. Hope you got it fixed 😃