webpack fails “module build failed: unknown word”

问题:

webpack does not work for me when trying to add css using the css-loader.

os: Windows 10 pro, webpack: 4.8.0 node: 8.9.4 npm: 6.0.0 css-loader: 0.28.11 style-loader: 0.21.0

package.json

  {
      "name": "webpack-dev",
      "version": "1.0.0",
      "description": "",
      "main": "index.php",
      "scripts": {
        "test": "echo \"Error: no test specified\" && exit 1",
        "build": "./src/app.js"
      },
      "keywords": [],
      "author": "",
      "license": "ISC",
      "devDependencies": {
        "babel-core": "^6.26.3",
        "babel-loader": "^7.1.4",
        "babel-preset-env": "^1.6.1",
        "css-loader": "^0.28.11",
        "extract-text-webpack-plugin": "^3.0.2",
        "file-loader": "^1.1.11",
        "node-sass": "^4.9.0",
        "raw-loader": "^0.5.1",
        "sass-loader": "^7.0.1",
        "style-loader": "^0.21.0",
        "url-loader": "^1.0.1",
        "webpack": "^4.8.1",
        "webpack-cli": "^2.1.3"
      }
    }

app.js

require('./style.css');
require('./scripts.js');

Error Message

Version: webpack 4.8.1
Time: 2157ms
Built at: 2018-05-09 14:13:17
    Asset      Size  Chunks             Chunk Names
bundle.js  3.68 KiB    main  [emitted]  main
Entrypoint main = bundle.js
[./src/app.js] 48 bytes {main} [built]
[./src/scripts.js] 28 bytes {main} [built]
[./src/style.css] 222 bytes {main} [built] [failed] [1 error]

ERROR in ./src/style.css
Module build failed: Unknown word (2:1)

  1 |
> 2 | var content = require("!!./style.css");
    | ^
  3 |
  4 | if(typeof content === 'string') content = [[module.id, content, '']];
  5 |

 @ ./src/app.js 1:0-22

style.css

body {
  color: red;
}

I just use the command webpack and it fails every time. This is the most frustrating tool ever. Nothing works except for if I put !! in front of the require statement i.e. require(!!'./style.css')

I have read every bug report about this I can find on npm, stackoverflow, etc., etc. but nothing seems to point to my problem. I literally followed the instructions verbatim from the modules section of webpack and it still isn't working. PLEASE HELP!

edit: forgot the config file

const webpack = require('webpack')
const path = require('path')

const config = {
  entry: './src/app.js',
  output: {
    filename: 'bundle.js',
    path: path.resolve(__dirname, 'dist')
  },
  mode: 'development',
  module: {
    rules: [
      {
        test: /\.(s*)css$/,
        use: [
          'sass-loader',
          'css-loader',
          'style-loader'
        ]
      },
      {
        test: /\.js$/,
        exclude: /(node_modules)/,
        use: [
          'babel-loader'
        ]
      },
      {
        test: /\.(png|svg|jpg)$/,
        use: [
          'file-loader'
        ]
      }
    ]
  }
};
module.exports = config;

Answer

Turns out order is important

...

use: [
    "style-loader",
    "css-loader",
    "sass-loader"
]

...

回答1:

In webpack, when you list multiple loaders within a rule, they are evaluated from right to left (in your case, bottom to top), so your scss rule should be:

  {
    test: /\.(s*)css$/,
    use: [
      'style-loader',
      'css-loader',
      'sass-loader'
    ]
  }

The reason is that first, you want your sass to compile to css, and then the css will be inlined in your html file via the style-loader.

Also, if you are not using sass, you can remove the sass-loader.

回答2:

Have check these issues getting similar issues in my web pack project You have to check the web pack rule :

{
    test: /\.(s*)css$/,
    use: [
      'style-loader',
      'css-loader',
      'sass-loader'
    ]
  }

Above, updated the rule it will handle our sass or CSS files. The test is test: /.(s*)css$/ : which means any file having name matching with regular expression /.(s*)css$/i.e. .scss or .css

It should be compiled with the chain of loaders specified in the use array i.e. ['style-loader', 'css-loader', 'sass-loader'].

This rule chain the output of sass-loader to css-loader. css-loader will take this css output of sass-loader and will also process any other .css files we have in our application and pass on the .css to style-loader, which will then do the job of putting the css codes inside tags in our index.html,It work bottom to top..