设置Webpack时遇到问题。
它显示了这样的错误。
您可能需要适当的加载程序来处理此文件类型，当前没有配置任何加载程序来处理此文件。参见https://webpack.js.org/concepts#loaders
| import * as React from 'react';
|
> const Page404: React.SFC = () => (
| <div>Page404</div>
| );
我在package.json的babel预设中添加了@ babel / preset-env。 也许显示代码可以使您更好地理解。.
package.json
{
"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,
},
},
],
},
],
},
答案 0 :(得分：-1)
您需要安装ts-loader并告诉webpack使用它：
SELECT
t.teamid,
t.`time`
FROM(
SELECT
d.teamid, -- Represent current row team id
d.`time`, -- Represent current row time
IF(@c_team_id = d.teamid, IF(@c_time = d.`time`, @rank, @rank:= @rank + 1), @rank:= 1) as rank, -- determine rank based on above explanation.
@c_team_id:= d.teamid, -- We are setting this variable to current row team id after using it in rank column, so rank column of next row will have this row team id for comparison using @c_team_id variable.
@c_time:= d.`time`
FROM `data` AS d,
(SELECT @c_time:= 0 as tim, @c_team_id:= 0 as tm_id, @rank:= 0 as rnk) AS t
WHERE d.`time` > 0 AND d.zid = 217456
ORDER BY d.teamid, d.`time` ASC -- Use to make sure we have same team records in sequence and with ascending order of time.
) AS t
WHERE t.rank = 4
GROUP BY t.teamid;
该加载程序经常与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,
}),
...
],
一起使用，因此该加载程序不必花时间检查语法错误，插件可以并行进行。