react x typescript x webpackで環境構築

create-react-appを使わずに環境構築する

## インストール

```
## package.json作る
$ yarn init -y 
## webpack
$ yarn add -D webpack webpack-cli webpack-dev-server html-webpack-plugin
## babel
$ yarn add -D babel-loader @babel/core @babel/preset-env @babel/preset-react
## react
$ yarn add -D react react-dom 
## typescript
$ yarn add -D typescript ts-loader 
$ typesync && yarn 
```

## tyconfig.json
tscのinitオプションで作成

```
$ npx tsc --init
```

```tsconfig.json
{
  "compilerOptions": {
    /* Visit https://aka.ms/tsconfig.json to read more about this file */

    /* Basic Options */
    // "incremental": true,                   /* Enable incremental compilation */
    "target": "es5",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019', 'ES2020', or 'ESNEXT'. */
    "module": "es2015",                     /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', 'es2020', 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": "react",                     /* 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 */
    // "tsBuildInfoFile": "./",               /* Specify file to store incremental compilation information */
    // "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. */
    // "noUncheckedIndexedAccess": true,      /* Include 'undefined' in index signature results */

    /* 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": {},                           /* 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. */
    // "allowUmdGlobalAccess": true,          /* Allow accessing UMD globals from modules. */

    /* 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. */

    /* Advanced Options */
    "skipLibCheck": true,                     /* Skip type checking of declaration files. */
    "forceConsistentCasingInFileNames": true  /* Disallow inconsistently-cased references to the same file. */
  }
}

```

## webpack.config.js　作成

```webpack.config.js
const path = require('path')
const HtmlWebpackPlugin = require('html-webpack-plugin')

module.exports = {
    mode: 'development',
    entry: path.resolve(__dirname, 'src', 'index.tsx'),
    output: {
        path: path.resolve(__dirname, 'dist'),
        filename: 'main.js'
    },
    module: {
        rules: [
            {
                test: /\.(js|jsx)$/,
                use: {
                    loader: 'babel-loader',
                    options: {
                        presets: [
                            '@babel/preset-env',
                            '@babel/react',
                        ]
                    }
                }
            },
            {
                test: /\.(ts|tsx)$/,
                use: {
                    loader: 'ts-loader',
                }
            }
        ]
    },
    plugins: [
        new HtmlWebpackPlugin({
            template: path.resolve(__dirname, 'src', 'index.html')
        })
    ],
    devServer: {
        contentBase: 'dist',
        open: true
    },
    resolve: {
        extensions: ['.js', '.jsx', '.ts', '.tsx', '.json']
    }
}
```

## package.json　追記

```package.json
{
  "name": "test5",
  "version": "1.0.0",
  "main": "index.js",
  "license": "MIT",
  "devDependencies": {
    "@babel/core": "^7.12.10",
    "@babel/preset-env": "^7.12.11",
    "@babel/preset-react": "^7.12.10",
    "@types/react": "^17.0.0",
    "@types/react-dom": "^17.0.0",
    "babel-loader": "^8.2.2",
    "html-webpack-plugin": "^4.5.0",
    "react": "^17.0.1",
    "react-dom": "^17.0.1",
    "ts-loader": "^8.0.12",
    "typescript": "^4.1.3",
    "webpack": "^5.11.0",
    "webpack-cli": "^4.3.0",
    "webpack-dev-server": "^3.11.0"
  },
  "scripts": {
    "start": "npx webpack serve"
  }
}
```


## ソース作成

```src/index.html
<!DOCTYPE html>
<body>
    <div id="app" />
</body>
```

```src/index.tsx
import React from 'react'
import ReactDOM from 'react-dom'
import Hoge from './components/Hoge'

const App = () => {
    return <div>
        react x typescript
        <Hoge />
    </div>
}

ReactDOM.render(<App />, document.getElementById('app'))
```

```src/components/Hoge.tsx
import React from 'react'

const Hoge = () => {
    return <div>Hoge</div>
}

export default Hoge
```

## 実行

```
$ yarn start
```

## 結果

![スクリーンショット 2020-12-27 23.42.26.png](https://qiita-image-store.s3.ap-northeast-1.amazonaws.com/0/278474/9cae8d7a-3081-7c39-89ab-724d1e68ee76.png)