"document is not defined" when criticalCSS is disabled in production

[phil294]

When I set

pluginOptions: {
    ssr: {
      criticalCSS: false

, build and run yarn ssr:build && yarn ssr:start, and then directly try to open up an existing subroute like localhost:8000/something, this fails with

(node:184939) UnhandledPromiseRejectionWarning: ReferenceError: document is not defined
    at js/app.e426663d.js:54:37
    at new Promise (<anonymous>:null:null)
    at Function.requireEnsure [as e] (webpack/bootstrap:49:0)
    at component (src/vue-router.coffee:17:17)
    at /b/ls/repo/web/node_modules/vue-router/dist/vue-router.common.js:1943:17
    ... etc ...
    at router.beforeEach (src/vue-router.coffee:47:3)
    at iterator (/b/ls/repo/web/node_modules/vue-router/dist/vue-router.common.js:2160:7)
    ... etc ...
    at new Promise (<anonymous>:null:null)
    at VueRouter.push (/b/ls/repo/web/node_modules/vue-router/dist/vue-router.common.js:2816:12)
    at Promise (src/entry-server.coffee:14:9)

My guess is, this line

vue-cli-plugin-ssr/lib/webpack.js

Line 27 in e9d0c4f

if (isExtracting && config.criticalCSS) {

is to be blamed. The

vue-cli-plugin-ssr/lib/webpack.js

Line 34 in e9d0c4f

rule.uses.delete('extract-css-loader')

below should always be called in production server mode, shouldn't it? Mini CSS Extract Plugin and SSR dont go along well. It is only the

vue-cli-plugin-ssr/lib/webpack.js

Line 36 in e9d0c4f

rule.use('css-context').loader(CssContextLoader).before('css-loader')

that should be triggered depending on whether criticalCSS is active.
Is this true? If so, I can create a pull request.
Edit: For the meantime, I fixed it here

As an alternative, maybe switch to https://github.com/faceyspacey/extract-css-chunks-webpack-plugin? But this probably needs more adjustments, as simply replacing MiniCSS with this one did not solve the issue for me.

Edit: For debugging purposes, I extracted the errorneous chunk from the vue-ssr-server-bundle.json:

module.exports =
/******/ (function(modules) { // webpackBootstrap
// [...]
/******/ 	// This file contains only the entry chunk.
/******/ 	// The chunk loading function for additional chunks
/******/ 	__webpack_require__.e = function requireEnsure(chunkId) {
/******/ 		var promises = [];
/******/ 		// extract-css-chunks-webpack-plugin CSS loading
/******/ 		var cssChunks = {"chunk-1163a9d5":1,"chunk-7ef57ddd":1};
/******/ 		if(installedCssChunks[chunkId]) promises.push(installedCssChunks[chunkId]);
/******/ 		else if(installedCssChunks[chunkId] !== 0 && cssChunks[chunkId]) {
/******/ 			promises.push(installedCssChunks[chunkId] = new Promise(function(resolve, reject) {
/******/ 				var href = "css/" + ({}[chunkId]||chunkId) + "." + {"chunk-1163a9d5":"5bffa29a","chunk-2d21e30b":"31d6cfe0","chunk-2d231056":"31d6cfe0","chunk-7ef57ddd":"939d4d1e"}[chunkId] + ".chunk.css";
/******/ 				var fullhref = __webpack_require__.p + href;
/******/ 				var existingLinkTags = document.getElementsByTagName("link");

It fails in the last line.