javascript - 找不到模块 : Can't resolve 'style'

Question

我正在尝试使用 sass 配置 css 模块。我遵循了一些教程，但似乎都没有用。 webpack 配置主要由 create-react-scripts 创建。我似乎收到此错误“找不到模块:无法解析‘样式’”任何帮助都会很棒。该错误似乎是在我下面的 Modal.js 文件中的导入语句中生成的。 (从“../css/modal.scss”导入样式；)我已经安装了 sass 加载器。我的 package.json 文件可以在下面找到。

webpack.config.dev.js:

'use strict';

const autoprefixer = require('autoprefixer');
const path = require('path');
const webpack = require('webpack');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const CaseSensitivePathsPlugin = require('case-sensitive-paths-webpack-plugin');
const InterpolateHtmlPlugin = require('react-dev-utils/InterpolateHtmlPlugin');
const WatchMissingNodeModulesPlugin = require('react-dev-utils/WatchMissingNodeModulesPlugin');
const eslintFormatter = require('react-dev-utils/eslintFormatter');
const ModuleScopePlugin = require('react-dev-utils/ModuleScopePlugin');
const getClientEnvironment = require('./env');
const paths = require('./paths');
const ExtractTextPlugin = require('extract-text-webpack-plugin');

// Webpack uses `publicPath` to determine where the app is being served from.
// In development, we always serve from the root. This makes config easier.
const publicPath = '/';
// `publicUrl` is just like `publicPath`, but we will provide it to our app
// as %PUBLIC_URL% in `index.html` and `process.env.PUBLIC_URL` in JavaScript.
// Omit trailing slash as %PUBLIC_PATH%/xyz looks better than %PUBLIC_PATH%xyz.
const publicUrl = '';
// Get environment variables to inject into our app.
const env = getClientEnvironment(publicUrl);

// This is the development configuration.
// It is focused on developer experience and fast rebuilds.
// The production configuration is different and lives in a separate file.
module.exports = {
  // You may want 'eval' instead if you prefer to see the compiled output in DevTools.
  // See the discussion in https://github.com/facebookincubator/create-react-app/issues/343.
  devtool: 'cheap-module-source-map',
  // These are the "entry points" to our application.
  // This means they will be the "root" imports that are included in JS bundle.
  // The first two entry points enable "hot" CSS and auto-refreshes for JS.
  entry: [
    // Include an alternative client for WebpackDevServer. A client's job is to
    // connect to WebpackDevServer by a socket and get notified about changes.
    // When you save a file, the client will either apply hot updates (in case
    // of CSS changes), or refresh the page (in case of JS changes). When you
    // make a syntax error, this client will display a syntax error overlay.
    // Note: instead of the default WebpackDevServer client, we use a custom one
    // to bring better experience for Create React App users. You can replace
    // the line below with these two lines if you prefer the stock client:
    // require.resolve('webpack-dev-server/client') + '?/',
    // require.resolve('webpack/hot/dev-server'),
    require.resolve('react-dev-utils/webpackHotDevClient'),
    // We ship a few polyfills by default:
    require.resolve('./polyfills'),
    // Errors should be considered fatal in development
    require.resolve('react-error-overlay'),
    // Finally, this is your app's code:
    paths.appIndexJs,
    // We include the app code last so that if there is a runtime error during
    // initialization, it doesn't blow up the WebpackDevServer client, and
    // changing JS code would still trigger a refresh.
  ],
  output: {
    // Next line is not used in dev but WebpackDevServer crashes without it:
    path: paths.appBuild,
    // Add /* filename */ comments to generated require()s in the output.
    pathinfo: true,
    // This does not produce a real file. It's just the virtual path that is
    // served by WebpackDevServer in development. This is the JS bundle
    // containing code from all our entry points, and the Webpack runtime.
    filename: 'static/js/bundle.js',
    // There are also additional JS chunk files if you use code splitting.
    chunkFilename: 'static/js/[name].chunk.js',
    // This is the URL that app is served from. We use "/" in development.
    publicPath: publicPath,
    // Point sourcemap entries to original disk location (format as URL on Windows)
    devtoolModuleFilenameTemplate: info =>
      path.resolve(info.absoluteResourcePath).replace(/\\/g, '/'),
  },
  resolve: {
    // This allows you to set a fallback for where Webpack should look for modules.
    // We placed these paths second because we want `node_modules` to "win"
    // if there are any conflicts. This matches Node resolution mechanism.
    // https://github.com/facebookincubator/create-react-app/issues/253
    modules: ['node_modules', paths.appNodeModules].concat(
      // It is guaranteed to exist because we tweak it in `env.js`
      process.env.NODE_PATH.split(path.delimiter).filter(Boolean)
    ),
    // These are the reasonable defaults supported by the Node ecosystem.
    // We also include JSX as a common component filename extension to support
    // some tools, although we do not recommend using it, see:
    // https://github.com/facebookincubator/create-react-app/issues/290
    // `web` extension prefixes have been added for better support
    // for React Native Web.
    extensions: ['.web.js', '.js', '.json', '.web.jsx', '.jsx'],
    alias: {

      // Support React Native Web
      // https://www.smashingmagazine.com/2016/08/a-glimpse-into-the-future-with-react-native-for-web/
      'react-native': 'react-native-web',
    },
    plugins: [
      // Prevents users from importing files from outside of src/ (or node_modules/).
      // This often causes confusion because we only process files within src/ with babel.
      // To fix this, we prevent you from importing files out of src/ -- if you'd like to,
      // please link the files into your node_modules/ and let module-resolution kick in.
      // Make sure your source files are compiled, as they will not be processed in any way.
      new ModuleScopePlugin(paths.appSrc),
    ],
  },
  module: {
    strictExportPresence: true,
    rules: [
      // TODO: Disable require.ensure as it's not a standard language feature.
      // We are waiting for https://github.com/facebookincubator/create-react-app/issues/2176.
      // { parser: { requireEnsure: false } },

      // First, run the linter.
      // It's important to do this before Babel processes the JS.
      {
        test: /\.(js|jsx)$/,
        enforce: 'pre',
        use: [
          {
            options: {
              formatter: eslintFormatter,

            },
            loader: require.resolve('eslint-loader'),
          },
        ],
        include: paths.appSrc,
      },
      // ** ADDING/UPDATING LOADERS **
      // The "file" loader handles all assets unless explicitly excluded.
      // The `exclude` list *must* be updated with every change to loader extensions.
      // When adding a new loader, you must add its `test`
      // as a new entry in the `exclude` list for "file" loader.

      // "file" loader makes sure those assets get served by WebpackDevServer.
      // When you `import` an asset, you get its (virtual) filename.
      // In production, they would get copied to the `build` folder.
      {
        exclude: [
          /\.html$/,
          /\.(js|jsx)$/,
          /\.css$/,
          /\.json$/,
          /\.bmp$/,
          /\.gif$/,
          /\.jpe?g$/,
          /\.png$/,
          /\.scss$/
        ],
        loader: require.resolve('file-loader'),
        options: {
          name: 'static/media/[name].[hash:8].[ext]',
        },
      },
      // "url" loader works like "file" loader except that it embeds assets
      // smaller than specified limit in bytes as data URLs to avoid requests.
      // A missing `test` is equivalent to a match.
      {
        test: [/\.bmp$/, /\.gif$/, /\.jpe?g$/, /\.png$/],
        loader: require.resolve('url-loader'),
        options: {
          limit: 10000,
          name: 'static/media/[name].[hash:8].[ext]',
        },
      },
      // Process JS with Babel.
      {
        test: /\.(js|jsx)$/,
        include: paths.appSrc,
        loader: require.resolve('babel-loader'),
        options: {

          // This is a feature of `babel-loader` for webpack (not Babel itself).
          // It enables caching results in ./node_modules/.cache/babel-loader/
          // directory for faster rebuilds.
          cacheDirectory: true,
        },
      },
      // "postcss" loader applies autoprefixer to our CSS.
      // "css" loader resolves paths in CSS and adds assets as dependencies.
      // "style" loader turns CSS into JS modules that inject <style> tags.
      // In production, we use a plugin to extract that CSS to a file, but
      // in development "style" loader enables hot editing of CSS.
      {
        test: /\.css$/,
        use: [
          require.resolve('style-loader'),
          {
            loader: require.resolve('css-loader'),
            options: {
              importLoaders: 1,
              modules: true,
              localIdentName: "[name]__[local]___[hash:base64:5]"
            },
          },
          {
            loader: require.resolve('postcss-loader'),
            options: {
              // Necessary for external CSS imports to work
              // https://github.com/facebookincubator/create-react-app/issues/2677
              ident: 'postcss',
              plugins: () => [
                require('postcss-flexbugs-fixes'),
                autoprefixer({
                  browsers: [
                    '>1%',
                    'last 4 versions',
                    'Firefox ESR',
                    'not ie < 9', // React doesn't support IE8 anyway
                  ],
                  flexbox: 'no-2009',
                }),
              ],
            },
          },
        ],
      },
      {
        test: /\.scss$/,
        use: ExtractTextPlugin.extract({
          fallback:'style-loader',
          use: [
            {
              loader: 'css-loader',
              q: {
                modules: true,
                sourcemap: true,
                importLoaders: 2,
                localIdentName: '[name]__[local]__[hash:base64:5]'
              }
            },
            'sass-loader'
          ]
        }),
        loaders: [
          require.resolve('style-loader'),
          require.resolve('css-loader'),
          require.resolve('sass-loader')
        ]
      }
      // ** STOP ** Are you adding a new loader?
      // Remember to add the new extension(s) to the "file" loader exclusion list.
    ],
  },
  plugins: [
    // Makes some environment variables available in index.html.
    // The public URL is available as %PUBLIC_URL% in index.html, e.g.:
    // <link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
    // In development, this will be an empty string.
    new InterpolateHtmlPlugin(env.raw),
    // Generates an `index.html` file with the <script> injected.
    new HtmlWebpackPlugin({
      inject: true,
      template: paths.appHtml,
    }),
    // Add module names to factory functions so they appear in browser profiler.
    new webpack.NamedModulesPlugin(),
    // Makes some environment variables available to the JS code, for example:
    // if (process.env.NODE_ENV === 'development') { ... }. See `./env.js`.
    new webpack.DefinePlugin(env.stringified),
    // This is necessary to emit hot updates (currently CSS only):
    new webpack.HotModuleReplacementPlugin(),
    // Watcher doesn't work well if you mistype casing in a path so we use
    // a plugin that prints an error when you attempt to do this.
    // See https://github.com/facebookincubator/create-react-app/issues/240
    new CaseSensitivePathsPlugin(),
    // If you require a missing module and then `npm install` it, you still have
    // to restart the development server for Webpack to discover it. This plugin
    // makes the discovery automatic so you don't have to restart.
    // See https://github.com/facebookincubator/create-react-app/issues/186
    new WatchMissingNodeModulesPlugin(paths.appNodeModules),
    // Moment.js is an extremely popular library that bundles large locale files
    // by default due to how Webpack interprets its code. This is a practical
    // solution that requires the user to opt into importing specific locales.
    // https://github.com/jmblog/how-to-optimize-momentjs-with-webpack
    // You can remove this if you don't use Moment.js:
    new webpack.IgnorePlugin(/^\.\/locale$/, /moment$/),

    new ExtractTextPlugin({'styles.css'}),
  ],
  // Some libraries import Node modules but don't use them in the browser.
  // Tell Webpack to provide empty mocks for them so importing them works.
  node: {
    dgram: 'empty',
    fs: 'empty',
    net: 'empty',
    tls: 'empty',
  },
  // Turn off performance hints during development because we don't do any
  // splitting or minification in interest of speed. These warnings become
  // cumbersome.
  performance: {
    hints: false,
  },
};

Modal.js 文件:

import React from "react";
import ReactDOM from "react-dom";
// import styles from "../css/popUpBox.css";
import styles from "../css/modal.scss"; // ERROR HAPPENS HERE!!

...文件继续

包.json :

{
  "name": "react-hackboard",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "autoprefixer": "7.1.1",
    "babel-core": "6.25.0",
    "babel-eslint": "7.2.3",
    "babel-jest": "20.0.3",
    "babel-loader": "7.0.0",
    "babel-preset-react-app": "^3.0.1",
    "babel-runtime": "6.23.0",
    "case-sensitive-paths-webpack-plugin": "2.1.1",
    "chalk": "1.1.3",
    "css-loader": "0.28.4",
    "dotenv": "4.0.0",
    "eslint": "3.19.0",
    "eslint-config-react-app": "^1.0.5",
    "eslint-loader": "1.7.1",
    "eslint-plugin-flowtype": "2.34.0",
    "eslint-plugin-import": "2.2.0",
    "eslint-plugin-jsx-a11y": "5.0.3",
    "eslint-plugin-react": "7.1.0",
    "extract-text-webpack-plugin": "2.1.2",
    "file-loader": "0.11.2",
    "fs-extra": "3.0.1",
    "html-webpack-plugin": "2.29.0",
    "jest": "20.0.4",
    "node-sass": "^4.5.3",
    "object-assign": "4.1.1",
    "postcss-flexbugs-fixes": "3.0.0",
    "postcss-loader": "2.0.6",
    "promise": "7.1.1",
    "react": "^15.6.1",
    "react-dev-utils": "^3.0.2",
    "react-dom": "^15.6.1",
    "react-error-overlay": "^1.0.9",
    "react-redux": "^5.0.5",
    "redux": "^3.7.2",
    "redux-createreducer": "^2.0.0",
    "redux-thunk": "^2.2.0",
    "sass-loader": "^6.0.6",
    "style-loader": "0.18.2",
    "sw-precache-webpack-plugin": "0.11.3",
    "url-loader": "0.5.9",
    "webpack": "2.6.1",
    "webpack-dev-server": "2.5.0",
    "webpack-manifest-plugin": "1.1.0",
    "whatwg-fetch": "2.0.3"
  },
  "scripts": {
    "start": "node scripts/start.js",
    "build": "node scripts/build.js",
    "test": "node scripts/test.js --env=jsdom"
  },
  "jest": {
    "collectCoverageFrom": [
      "src/**/*.{js,jsx}"
    ],
    "setupFiles": [
      "<rootDir>/config/polyfills.js"
    ],
    "testMatch": [
      "<rootDir>/src/**/__tests__/**/*.js?(x)",
      "<rootDir>/src/**/?(*.)(spec|test).js?(x)"
    ],
    "testEnvironment": "node",
    "testURL": "http://localhost",
    "transform": {
      "^.+\\.(js|jsx)$": "<rootDir>/node_modules/babel-jest",
      "^.+\\.css$": "<rootDir>/config/jest/cssTransform.js",
      "^(?!.*\\.(js|jsx|css|json)$)": "<rootDir>/config/jest/fileTransform.js"
    },
    "transformIgnorePatterns": [
      "[/\\\\]node_modules[/\\\\].+\\.(js|jsx)$"
    ],
    "moduleNameMapper": {
      "^react-native$": "react-native-web"
    },
    "moduleFileExtensions": [
      "web.js",
      "js",
      "json",
      "web.jsx",
      "jsx"
    ]
  },
  "babel": {
    "presets": [
      "react-app"
    ]
  },
  "eslintConfig": {
    "extends": "react-app"
  },
  "devDependencies": {
    "node-sass": "^4.5.3",
    "sass-loader": "^6.0.6",
    "webpack": "^2.6.1"
  }
}

Answer 1

这是说找不到特定加载程序的依赖项。您可以通过执行以下操作来解决它

yarn add style-loader css-loader sass-loader

如下修改加载器配置:

      {
        test: /\.scss$/,
        include: paths.appSrc,
        loaders: [
          require.resolve('style-loader'),
          require.resolve('css-loader'),
          require.resolve('sass-loader')
        ]
      }

这应该让 scss 工作。