react-typescript-您可能需要一个适当的加载器来处理这个文件类型，目前没有配置加载器来处理这个文件

Question

我在设置WebPack时遇到了一个问题。

| import * as React from 'react';
|
> const Page404: React.SFC = () => (
|   <div>Page404</div>
| );

{
  "name": "pay",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "@babel/core": "7.5.5",
    "@babel/plugin-syntax-dynamic-import": "^7.2.0",
    "@babel/preset-env": "^7.6.0",
    "@babel/preset-react": "^7.0.0",
    "@babel/preset-typescript": "^7.6.0",
    "@svgr/webpack": "4.3.2",
    "@types/axios": "^0.14.0",
    "@types/jest": "^24.0.18",
    "@types/lodash": "^4.14.138",
    "@types/node": "12.7.3",
    "@types/react": "16.9.2",
    "@types/react-dom": "16.9.0",
    "@types/react-redux": "^7.1.2",
    "@types/react-router": "^5.0.3",
    "@types/react-router-dom": "^4.3.5",
    "@types/redux": "^3.6.0",
    "@types/redux-actions": "^2.6.1",
    "@types/redux-devtools-extension": "^2.13.2",
    "@types/redux-thunk": "^2.1.0",
    "@types/styled-components": "^4.1.18",
    "@typescript-eslint/eslint-plugin": "1.13.0",
    "@typescript-eslint/parser": "1.13.0",
    "axios": "^0.19.0",
    "axios-extensions": "^3.0.6",
    "babel-eslint": "10.0.2",
    "babel-jest": "^24.8.0",
    "babel-loader": "^8.0.6",
    "babel-plugin-named-asset-import": "^0.3.3",
    "babel-preset-react-app": "^9.0.1",
    "camelcase": "^5.2.0",
    "case-sensitive-paths-webpack-plugin": "2.2.0",
    "css-loader": "2.1.1",
    "dayjs": "^1.8.16",
    "dotenv": "6.2.0",
    "dotenv-expand": "4.2.0",
    "eslint": "^6.1.0",
    "eslint-config-react-app": "^5.0.1",
    "eslint-loader": "2.2.1",
    "eslint-plugin-flowtype": "3.13.0",
    "eslint-plugin-import": "2.18.2",
    "eslint-plugin-jsx-a11y": "6.2.3",
    "eslint-plugin-react": "7.14.3",
    "eslint-plugin-react-hooks": "^1.6.1",
    "file-loader": "3.0.1",
    "fs-extra": "7.0.1",
    "html-webpack-plugin": "4.0.0-beta.5",
    "identity-obj-proxy": "3.0.0",
    "is-wsl": "^1.1.0",
    "jest": "24.8.0",
    "jest-environment-jsdom-fourteen": "0.1.0",
    "jest-resolve": "24.8.0",
    "jest-watch-typeahead": "0.3.1",
    "lodash": "^4.17.15",
    "mini-css-extract-plugin": "0.5.0",
    "optimize-css-assets-webpack-plugin": "5.0.3",
    "pnp-webpack-plugin": "1.5.0",
    "postcss-flexbugs-fixes": "4.1.0",
    "postcss-loader": "3.0.0",
    "postcss-normalize": "7.0.1",
    "postcss-preset-env": "6.7.0",
    "postcss-safe-parser": "4.0.1",
    "react": "^16.9.0",
    "react-app-polyfill": "^1.0.2",
    "react-dev-utils": "^9.0.3",
    "react-dom": "^16.9.0",
    "react-redux": "^7.1.1",
    "react-router": "^5.0.1",
    "react-router-dom": "^5.0.1",
    "redux": "^4.0.4",
    "redux-actions": "^2.6.5",
    "redux-devtools-extension": "^2.13.8",
    "redux-thunk": "^2.3.0",
    "resolve": "1.12.0",
    "resolve-url-loader": "3.1.0",
    "sass-loader": "7.2.0",
    "semver": "6.3.0",
    "style-loader": "1.0.0",
    "styled-components": "^4.3.2",
    "terser-webpack-plugin": "1.4.1",
    "ts-pnp": "1.1.2",
    "tslint": "^5.19.0",
    "tslint-react": "^4.0.0",
    "typescript": "3.6.2",
    "url-loader": "2.1.0",
    "webpack": "^4.39.3",
    "webpack-dev-server": "3.2.1",
    "webpack-manifest-plugin": "2.0.4",
    "workbox-webpack-plugin": "4.3.1"
  },
  "scripts": {
    "start": "node scripts/start.js",
    "build": "node scripts/build.js",
    "test": "node scripts/test.js"
  },
  "eslintConfig": {
    "extends": "react-app"
  },
  "browserslist": {
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ]
  },
  "jest": {
    "roots": [
      "<rootDir>/src"
    ],
    "collectCoverageFrom": [
      "src/**/*.{js,jsx,ts,tsx}",
      "!src/**/*.d.ts"
    ],
    "setupFiles": [
      "react-app-polyfill/jsdom"
    ],
    "setupFilesAfterEnv": [],
    "testMatch": [
      "<rootDir>/src/**/__tests__/**/*.{js,jsx,ts,tsx}",
      "<rootDir>/src/**/*.{spec,test}.{js,jsx,ts,tsx}"
    ],
    "testEnvironment": "jest-environment-jsdom-fourteen",
    "transform": {
      "^.+\\.(js|jsx|ts|tsx)$": "<rootDir>/node_modules/babel-jest",
      "^.+\\.css$": "<rootDir>/config/jest/cssTransform.js",
      "^(?!.*\\.(js|jsx|ts|tsx|css|json)$)": "<rootDir>/config/jest/fileTransform.js"
    },
    "transformIgnorePatterns": [
      "[/\\\\]node_modules[/\\\\].+\\.(js|jsx|ts|tsx)$",
      "^.+\\.module\\.(css|sass|scss)$"
    ],
    "modulePaths": [],
    "moduleNameMapper": {
      "^react-native$": "react-native-web",
      "^.+\\.module\\.(css|sass|scss)$": "identity-obj-proxy"
    },
    "moduleFileExtensions": [
      "web.js",
      "js",
      "web.ts",
      "ts",
      "web.tsx",
      "tsx",
      "json",
      "web.jsx",
      "jsx",
      "node"
    ],
    "watchPlugins": [
      "jest-watch-typeahead/filename",
      "jest-watch-typeahead/testname"
    ]
  },
  "babel": {
    "presets": [
      "react-app",
      "@babel/preset-env"
    ],
    "plugins": [
      "@babel/plugin-syntax-dynamic-import"
    ]
  }
}

webpack.config.ts-模块

module: {
      strictExportPresence: true,
      rules: [
        // Disable require.ensure as it's not a standard language feature.
        { parser: { requireEnsure: false } },

        // First, run the linter.
        // It's important to do this before Babel processes the JS.
        {
          test: /\.(js|mjs|jsx|ts|tsx)$/,
          enforce: 'pre',
          use: [
            {
              options: {
                formatter: require.resolve('react-dev-utils/eslintFormatter'),
                eslintPath: require.resolve('eslint'),
                resolvePluginsRelativeTo: __dirname,

              },
              loader: require.resolve('eslint-loader'),
            },
          ],
          include: paths.appSrc,
        },
        {
          // "oneOf" will traverse all following loaders until one will
          // match the requirements. When no loader matches it will fall
          // back to the "file" loader at the end of the loader list.
          oneOf: [
            // "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: imageInlineSizeLimit,
                name: 'static/media/[name].[hash:8].[ext]',
              },
            },
            // Process application JS with Babel.
            // The preset includes JSX, Flow, TypeScript, and some ESnext features.
            {
              test: /\.(js|mjs|jsx|ts|tsx)$/,
              include: paths.appSrc,
              loader: require.resolve('babel-loader'),
              options: {
                customize: require.resolve(
                  'babel-preset-react-app/webpack-overrides'
                ),

                plugins: [
                  [
                    require.resolve('babel-plugin-named-asset-import'),
                    {
                      loaderMap: {
                        svg: {
                          ReactComponent:
                            '@svgr/webpack?-svgo,+titleProp,+ref![path]',
                        },
                      },
                    },
                  ],
                ],
                // 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,
                cacheCompression: isEnvProduction,
                compact: isEnvProduction,
              },
            },
            // Process any JS outside of the app with Babel.
            // Unlike the application JS, we only compile the standard ES features.
            {
              test: /\.(js|mjs)$/,
              exclude: /@babel(?:\/|\\{1,2})runtime/,
              loader: require.resolve('babel-loader'),
              options: {
                babelrc: false,
                configFile: false,
                compact: false,
                presets: [
                  [
                    require.resolve('babel-preset-react-app/dependencies'),
                    { helpers: true },
                  ],
                ],
                cacheDirectory: true,
                cacheCompression: isEnvProduction,

                // If an error happens in a package, it's possible to be
                // because it was compiled. Thus, we don't want the browser
                // debugger to show the original code. Instead, the code
                // being evaluated would be much more helpful.
                sourceMaps: false,
              },
            },
          ],
        },
      ],
    },

Answer 1

您需要安装ts-loader并告诉webpack使用它：

const ForkTsCheckerWebpackPlugin = require('fork-ts-checker-webpack-plugin');
     ...
    module: {
      rules: [
        {
          test: /\.tsx?$/,
          exclude: /node_modules/,
          use: [
            {
              loader: 'ts-loader',
              options: {
                transpileOnly: true,
                happyPackMode: true,
                configFile: path.resolve(__dirname, 'tsconfig.json'),
              },
            }
          ],
         ...
    },
    plugins: [
      new ForkTsCheckerWebpackPlugin({
        tslint: false,      // change to 'true' later
        useTypescriptIncrementalApi: true,
        checkSyntacticErrors: true,
      }),
     ...
    ], 

加载器经常与fork-ts-checker-webpack-plugin一起使用，这样加载器就不必花时间检查语法错误，而插件是并行进行的。