react: typescript project initialize

Initialize the project

create a folder project

Now we’ll turn this folder into an npm package.

npm init -y

This creates a package.json file with default values.

Install our dependencies

First ensure Webpack is installed.

npm install --save-dev webpack webpack-cli

Webpack is a tool that will bundle your code and optionally all of its dependencies into a single .js file.

Let’s now add React and React-DOM, along with their declaration files, as dependencies to your package.json file:

npm install --save react react-dom
npm install --save-dev @types/react @types/react-dom

That @types/ prefix means that we also want to get the declaration files for React and React-DOM. Usually when you import a path like "react", it will look inside of the react package itself; however, not all packages include declaration files, so TypeScript also looks in the @types/react package as well. You’ll see that we won’t even have to think about this later on.

Next, we’ll add development-time dependencies on the ts-loader and source-map-loader.

npm install --save-dev typescript ts-loader source-map-loader

Both of these dependencies will let TypeScript and webpack play well together. ts-loader helps Webpack compile your TypeScript code using the TypeScript’s standard configuration file named tsconfig.json. source-map-loader uses any sourcemap outputs from TypeScript to inform webpack when generating its own sourcemaps. This will allow you to debug your final output file as if you were debugging your original TypeScript source code.

Please note that ts-loader is not the only loader for typescript. You could instead use awesome-typescript-loader.

Read about the differences between them:

https://github.com/s-panferov/awesome-typescript-loader#differences-between-ts-loader

Notice that we installed TypeScript as a development dependency. We could also have linked TypeScript to a global copy with npm link typescript, but this is a less common scenario.

Add a TypeScript configuration file #

You’ll want to bring your TypeScript files together - both the code you’ll be writing as well as any necessary declaration files.

To do this, you’ll need to create a tsconfig.json which contains a list of your input files as well as all your compilation settings. Simply create a new file in your project root named tsconfig.json and fill it with the following contents:

{
    "compilerOptions": {
        "outDir": "./dist/",
        "sourceMap": true,
        "noImplicitAny": true,
        "module": "commonjs",
        "target": "es6",
        "jsx": "react"
    }
}

You can learn more about tsconfig.json files:

http://www.typescriptlang.org/docs/handbook/tsconfig-json.html

Write some code

Let’s write our first TypeScript file using React. First, create a file named Hello.tsx in src/components and write the following:

import * as React from "react";

export interface HelloProps { compiler: string; framework: string; }

export const Hello = (props: HelloProps) => <h1>Hello from {props.compiler} and {props.framework}!</h1>;

Note that while this example uses function components, we could also make our example a little classier as well.

import * as React from "react";

export interface HelloProps { compiler: string; framework: string; }

// 'HelloProps' describes the shape of props.
// State is never set so we use the '{}' type.
export class Hello extends React.Component<HelloProps, {}> {
    render() {
        return <h1>Hello from {this.props.compiler} and {this.props.framework}!</h1>;
    }
}

Next, let’s create an index.tsx in src with the following source:

import * as React from "react";
import * as ReactDOM from "react-dom";

import { Hello } from "./components/Hello";

ReactDOM.render(
    <Hello compiler="TypeScript" framework="React" />,
    document.getElementById("example")
);

We just imported our Hello component into index.tsx. Notice that unlike with "react" or "react-dom", we used a relative path to Hello.tsx - this is important. If we hadn’t, TypeScript would’ve instead tried looking in our node_modules folder.

We’ll also need a page to display our Hello component. Create a file at the root of proj named index.htmlwith the following contents:

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8" />
        <title>Hello React!</title>
    </head>
    <body>
        <div id="example"></div>

        <!-- Dependencies -->
        <script src="./node_modules/react/umd/react.development.js"></script>
        <script src="./node_modules/react-dom/umd/react-dom.development.js"></script>

        <!-- Main -->
        <script src="./dist/main.js"></script>
    </body>
</html>

Notice that we’re including files from within node_modules. React and React-DOM’s npm packages include standalone .js files that you can include in a web page, and we’re referencing them directly to get things moving faster. Feel free to copy these files to another directory, or alternatively, host them on a content delivery network (CDN). Facebook makes CDN-hosted versions of React available, and you can read more about that here.

https://reactjs.org/docs/getting-started.html#development-vs.-production-builds

Create a webpack configuration file

Create a webpack.config.js file at the root of the project directory.

module.exports = {
    mode: "production",

    // Enable sourcemaps for debugging webpack's output.
    devtool: "source-map",

    resolve: {
        // Add '.ts' and '.tsx' as resolvable extensions.
        extensions: [".ts", ".tsx"]
    },

    module: {
        rules: [
            {
                test: /\.ts(x?)$/,
                exclude: /node_modules/,
                use: [
                    {
                        loader: "ts-loader"
                    }
                ]
            },
            // All output '.js' files will have any sourcemaps re-processed by 'source-map-loader'.
            {
                enforce: "pre",
                test: /\.js$/,
                loader: "source-map-loader"
            }
        ]
    },

    // When importing a module whose path matches one of the following, just
    // assume a corresponding global variable exists and use that instead.
    // This is important because it allows us to avoid bundling all of our
    // dependencies, which allows browsers to cache those libraries between builds.
    externals: {
        "react": "React",
        "react-dom": "ReactDOM"
    }
};

Putting it all together

npx webpack

引入html-webpack-plugin 实现html模版自动生成

const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');

module.exports = {
  entry: "./src/index.tsx",
  output: {
    path: path.join(__dirname, '/dist'),
    filename: 'bundle.js'
  },
  devtool: "source-map",
  resolve: {
  // Add '.ts' and '.tsx' as resolvable extensions.
   extensions: [".ts", ".tsx", ".js", ".json"]
  },
  module: {
    rules: [
      // All files with a '.ts' or '.tsx' extension will be handled by 'awesome-typescript-loader’.
      { test: /\.tsx?$/, loader: "awesome-typescript-loader" },
      // All output '.js' files will have any sourcemaps re-processed by 'source-map-loader'.
      { enforce: "pre", test: /\.js$/, loader: "source-map-loader" }
    ]
  },
  plugins: [
    new HtmlWebpackPlugin({
    template: './index.html'
   })
  ],
  // 用来替换全局变量
  // externals: {
    // react: "React",
    // "react-dom": "ReactDOM"
// }
};

npm i webpack-dev-server -D

更新package.json

"scripts": {
  "start": "webpack-dev-server --mode development --open --hot",
  "build": "webpack --mode production"
}