在 VSCode 中使用路径别名也有提示

场景

最近在学 ReactJS，遇到了一个很奇怪的问题。当吾辈在 webpack 配置中配置了路径别名之后，VSCode 再输入路径便没有了提示。

路径别名配置

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',
  '@': path.resolve(__dirname, '../src'),
},

吾辈也安装了 Path Intellisense 插件，然而这毫无意义，仍然是只有在相对路径的情况下才会提示。

解决

抱着这个疑问，吾辈稍微去搜索了一下。然后，找到了 webpack 自定义别名后，VScode 路径提示问题 这个问题。在下面的回答中，吾辈找到了答案。

注：这里已采纳的答案实际上应该是复制少了一个括号导致实际使用会出错，不过确实是正确答案。

在项目根目录下添加 jsconfig.json 并添加以下配置

{
  "compilerOptions": {
    "baseUrl": "./",
    "paths": {
      "@/*": ["src/*"]
    }
  }
}

然后重启 VSCode，之后，一切便恢复了理想状态！

原因

那么，jsconfig.json 到底是什么神奇的东西，为什么能影响到 VSCode 的提示呢？吾辈找到了 VSCode 官网上的文档，文档上对此的说明是：VSCode 大部分功能都是开箱即用，然而有些却需要进行一些基本的配置才能获得最佳体验，jsconfig 就是用来配置 JavaScript 语言的相关功能。

所以，原因明了了，这是 VSCode 内置的功能，就是为了便于开发的。而我们仅仅需要做一些简单的配置，即可使用这些功能。
吾辈也使用 tsc 命令生成了一份 jsconfig.json（由 tsconfig.json 改名），泥萌可以复制并按照自己的需求修改其中的配置。

{
  "compilerOptions": {
    /* Basic Options */
    "target": "ES2018" /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017','ES2018' or 'ESNEXT'. */,
    "module": "es2015" /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */,
    // "lib": [],                             /* Specify library files to be included in the compilation. */
    // "allowJs": true,                       /* Allow javascript files to be compiled. */
    // "checkJs": true,                       /* Report errors in .js files. */
    // "jsx": "preserve",                     /* Specify JSX code generation: 'preserve', 'react-native', or 'react'. */
    // "declaration": true,                   /* Generates corresponding '.d.ts' file. */
    // "declarationMap": true,                /* Generates a sourcemap for each corresponding '.d.ts' file. */
    // "sourceMap": true,                     /* Generates corresponding '.map' file. */
    // "outFile": "./",                       /* Concatenate and emit output to single file. */
    // "outDir": "./",                        /* Redirect output structure to the directory. */
    // "rootDir": "./",                       /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
    // "composite": true,                     /* Enable project compilation */
    // "removeComments": true,                /* Do not emit comments to output. */
    // "noEmit": true,                        /* Do not emit outputs. */
    // "importHelpers": true,                 /* Import emit helpers from 'tslib'. */
    // "downlevelIteration": true,            /* Provide full support for iterables in 'for-of', spread, and destructuring when targeting 'ES5' or 'ES3'. */
    // "isolatedModules": true,               /* Transpile each file as a separate module (similar to 'ts.transpileModule'). */

    /* Strict Type-Checking Options */
    "strict": true /* Enable all strict type-checking options. */,
    // "noImplicitAny": true,                 /* Raise error on expressions and declarations with an implied 'any' type. */
    // "strictNullChecks": true,              /* Enable strict null checks. */
    // "strictFunctionTypes": true,           /* Enable strict checking of function types. */
    // "strictBindCallApply": true,           /* Enable strict 'bind', 'call', and 'apply' methods on functions. */
    // "strictPropertyInitialization": true,  /* Enable strict checking of property initialization in classes. */
    // "noImplicitThis": true,                /* Raise error on 'this' expressions with an implied 'any' type. */
    // "alwaysStrict": true,                  /* Parse in strict mode and emit "use strict" for each source file. */

    /* Additional Checks */
    // "noUnusedLocals": true,                /* Report errors on unused locals. */
    // "noUnusedParameters": true,            /* Report errors on unused parameters. */
    // "noImplicitReturns": true,             /* Report error when not all code paths in function return a value. */
    // "noFallthroughCasesInSwitch": true,    /* Report errors for fallthrough cases in switch statement. */

    /* Module Resolution Options */
    // "moduleResolution": "node",            /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */
    "baseUrl": "./" /* Base directory to resolve non-absolute module names. */,
    "paths": {
      "@/*": ["src/*"]
    } /* A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. */,
    // "rootDirs": [],                        /* List of root folders whose combined content represents the structure of the project at runtime. */
    // "typeRoots": [],                       /* List of folders to include type definitions from. */
    // "types": [],                           /* Type declaration files to be included in compilation. */
    // "allowSyntheticDefaultImports": true,  /* Allow default imports from modules with no default export. This does not affect code emit, just typechecking. */
    "esModuleInterop": true /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */
    // "preserveSymlinks": true,              /* Do not resolve the real path of symlinks. */

    /* Source Map Options */
    // "sourceRoot": "",                      /* Specify the location where debugger should locate TypeScript files instead of source locations. */
    // "mapRoot": "",                         /* Specify the location where debugger should locate map files instead of generated locations. */
    // "inlineSourceMap": true,               /* Emit a single file with source maps instead of having a separate file. */
    // "inlineSources": true,                 /* Emit the source alongside the sourcemaps within a single file; requires '--inlineSourceMap' or '--sourceMap' to be set. */

    /* Experimental Options */
    // "experimentalDecorators": true,        /* Enables experimental support for ES7 decorators. */
    // "emitDecoratorMetadata": true,         /* Enables experimental support for emitting type metadata for decorators. */
  }
}