11 如何用TS从零初始化一个项目

1 本文的目标是什么?

有时候我就是想从零开始去做写个项目，就是那种创建一个空目录然后一步一步来的那种，而这个项目主要用的就是TS. 而ts当前的node是不能执行的， 所以本项目本质上就是用ts写代码，然后编译成js代码，最后交给node运行，这就是本项目最主要的事了。

2 相关准备

名称	必要	示例	说明
node	✅	v16	用来执行js或ts的运行时引擎
pnpm	✅	6.32.4	包管理工具,同npm或yarn是一样的
git	✅		代码版本控制工具

3 初始化项目

3.1 初始化软件工程

初始化项目

$ mkdir dynamicDNS # 创建一个名为 howToInitTSProject
$ cd dynamicDNS    # 进入目录
$ pnpm init        # 初始化软件工程
pnpm init
This utility will walk you through creating a package.json file.
It only covers the most common items, and tries to guess sensible defaults.

See `npm help init` for definitive documentation on these fields
and exactly what they do.

Use `npm install <pkg>` afterwards to install a package and
save it as a dependency in the package.json file.

Press ^C at any time to quit.
package name: (dynamicdns)
version: (1.0.0)
description:
// highlight-start
entry point: (index.js) dist/index.js # 填写 dist/indexjs
// highlight-end
test command:
git repository:
keywords:
author:
license: (ISC)
About to write to /Users/wuchuheng/tmp/dynamicDNS/package.json:

{
  "name": "dynamicdns",
  "version": "1.0.0",
  "description": "",
  "main": "dist/index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC"
}


Is this OK? (yes)

当前项目文件树

.
└── package.json

3.2 配置代码版本控制git

这一步目的是为了更好地管理代码

配置git忽略文件

.gitignore

dist # 用于存放编译后的代码
node_modules
.pnpm-debug.log

初始化git

$ git init
$ git add -A
$ git commit -m init

当前项目文件树

├── .git
├── .gitignore
├── package.json
└── package.json

4 添加typescript到项目中

4.1 安装typescript并初始化配置

我们只有安装好ts和配置好ts的配置，ts代码编译成js代码。这是我们这一步要做的工作

安装typescript并初始化配置

$ pnpm i -D typescript # 安装typescript到项目中
$ pnpx tsc --init      # 为项目根目录生成ts的配置文件 tsconfig.json

修改tsconfig.json

{
  "compilerOptions": {
    "target": "es2016", // 编译后的js版本
    "module": "commonjs", // js的导出模块类型
    "declaration": true, // 编译导出包含类型文件
    "outDir": "dist", // 编译后导出的目录
    "esModuleInterop": true,                             /* Emit additional JavaScript to ease support for importing CommonJS modules. This enables 'allowSyntheticDefaultImports' for type compatibility. */
    "rootDir": "src", // 要编译的代码开始目录
    "forceConsistentCasingInFileNames": true,            /* Ensure that casing is correct in imports. */
    "strict": true,                                      /* Enable all strict type-checking options. */
    "skipLibCheck": true                                 /* Skip type checking all .d.ts files. */
  },
  // ts编译时忽略的文件
  "exclude": [
    "node_modules",
    "dist"
  ]
}

4.2 添加项目源代码

src/index.ts

const main = () => {
    console.log("Hello world!!!")
}

export default main()

4.3 配置编译配置

package.json

{
  "name": "dynamicdns",
  "version": "0.0.1",
  "description": "",
  "main": "dist/index.js",
  "scripts": {
    "dev:build": "tsc --sourceMap true --declarationMap true", // 用于开发模式下使用，在编译成js的同时也会生成与源代码关联找配置文件，方便定位编译的代码与源代码之间的位置
    "build": "tsc", // 直接编译成js
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "typescript": "^4.9.3"
  }
}

4.4 ts和源代码已经准备好，可以进行编译了

$ pnpm build # 然后会在`dist`目录生成编译好的`js`文件。

> dynamicdns@0.0.1 build /Users/wuchuheng/Desktop/myprojects/wuchuheng/npm/dynamicDNS
> tsc

$ node dist/index.js # 执行代码
Hello world!!!

4.5 提交下代码

$ git commit -m 'chore: 安装ts和相关配置'
[master 71b0131] chore: 安装ts和相关配置
 4 files changed, 42 insertions(+), 2 deletions(-)
 create mode 100644 pnpm-lock.yaml
 create mode 100644 tsconfig.json

当前项目文件树

.
├── .git
├── .gitignore
├── .pnpm-debug.log
├── dist
│   ├── index.d.ts
│   ├── index.js
├── node_modules
├── package.json
├── pnpm-lock.yaml
├── src
│   └── index.ts
└── tsconfig.json

5 自动编译ts

在开发过程中，如何每一次修改都要手动去编译很麻烦，所以这里需要引入自动编译流程来提高开发效率. 而nodemon是一个能监听文件变动时自动执行相关命令的工具，通过它就能实现源代码变动时，然后自动去执行编译命令。从而实现编译自动化。

5.1 安装nodemon并配置

安装nodemon

$ pnpm install --save-dev nodemon

5.2 添加nodemon配置文件

nodemon.json

{
  "watch": ["src/**"],
  "ext": "ts"
}

watch字段指明只监听src目录下的文件变动,而ext指明变动文件的后缀。

5.3 添加package.json的启动脚本

package.json

{
  "name": "dynamicdns",
  "version": "0.0.1",
  "description": "",
  "main": "dist/index.js",
  "scripts": {
    "dev": "nodemon --exec \"npm run dev:build\"",
    "dev:build": "tsc --sourceMap true --declarationMap true",
    "build": "tsc",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "nodemon": "^2.0.20",
    "typescript": "^4.9.3"
  }
}

5.4 启动自动编译功能

$ pnpm run dev # <-- 启动自动编译的脚本命令

> dynamicdns@0.0.1 dev /Users/wuchuheng/Desktop/myprojects/wuchuheng/npm/dynamicDNS
> nodemon --exec "npm run dev:build"

[nodemon] 2.0.20
[nodemon] to restart at any time, enter `rs`
[nodemon] watching path(s): src/**
[nodemon] watching extensions: ts
[nodemon] starting `npm run dev:build`

然后在src目录下的ts文件变动时就会自动编译成js文件导出到dist目录中，而不用手动去操作，节省开发时间提高效率。

5.4 提交关于"启动自动编译功能"的代码

此次功能变动的文件

$ git add -A
$ git status
On branch master
Changes to be committed:
(use "git restore --staged file ..." to unstage)
new file:   nodemon.json
modified:   package.json
modified:   pnpm-lock.yaml

提交代码

$ git commit -m 'chore: 开发自动编译ts.'

当前项目文件树

.
├── .git
├── .gitignore
├── .pnpm-debug.log
├── dist
├── node_modules
├── nodemon.json
├── package.json
├── pnpm-lock.yaml
├── src
│   └── index.ts
└── tsconfig.json

6 自动启动程序

尽管我们以上的开发流程已经实现自动化编译了，可是还是要手动去重启下，这是很费时间的，应该在自动编译完代码后就也自动启动程序这才可以. 所在package.json中加入自动编译后就自动重启程序。

为自动重启程序而配置package.json

{
// ...
  "scripts": {
    "dev": "nodemon --exec \"npm run dev:build && npm run start\"",
    "start": "node dist/index.js",
    "dev:build": "tsc --sourceMap true --declarationMap true",
    "build": "tsc",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
// ...
}

这样一来，当执行pnpm run dev时，就会自动编译程序并启动程序，而src的ts文件被修改后也会自动编译并重启的，如:

step 1: 先启动开发模式`pnpm run dev`

> dynamicdns@0.0.1 dev /Users/wuchuheng/Desktop/myprojects/wuchuheng/npm/dynamicDNS
> nodemon --exec "npm run dev:build && npm run start"

[nodemon] 2.0.20
[nodemon] to restart at any time, enter `rs`
[nodemon] watching path(s): src/**
[nodemon] watching extensions: ts
[nodemon] starting `npm run dev:build && npm run start`

> dynamicdns@0.0.1 dev:build
> tsc --sourceMap true --declarationMap true


> dynamicdns@0.0.1 start
> node dist/index.js

Hello world!!!

step 2: 修改源代码 src/index.ts

const main = () => {
    console.log("Are you ok?")
}

export default main()

step 3: 自动重启修改后的代码

$ pnpm run dev

> dynamicdns@0.0.1 dev /Users/wuchuheng/Desktop/myprojects/wuchuheng/npm/dynamicDNS
> nodemon --exec "npm run dev:build && npm run start"

[nodemon] 2.0.20
[nodemon] to restart at any time, enter `rs`
[nodemon] watching path(s): src/**
[nodemon] watching extensions: ts
[nodemon] starting `npm run dev:build && npm run start`

> dynamicdns@0.0.1 dev:build
> tsc --sourceMap true --declarationMap true


> dynamicdns@0.0.1 start
> node dist/index.js

Hello world!!!
[nodemon] clean exit - waiting for changes before restart
[nodemon] restarting due to changes...
[nodemon] starting `npm run dev:build && npm run start`

> dynamicdns@0.0.1 dev:build
> tsc --sourceMap true --declarationMap true


> dynamicdns@0.0.1 start
> node dist/index.js


Are you ok? # 输入修改后的结果
[nodemon] clean exit - waiting for changes before restart

6.1 自动重启小结

本次实现开发模式下自动重启功能，并有了如下的代码发动:

diff --git a/package.json b/package.json
index 26a18f7..edce3cb 100644
--- a/package.json
+++ b/package.json
@@ -4,7 +4,8 @@
   "description": "",
   "main": "dist/index.js",
   "scripts": {
-    "dev": "nodemon --exec \"npm run dev:build\"",
+    "dev": "nodemon --exec \"npm run dev:build && npm run start\"",
+    "start": "node dist/index.js",
     "dev:build": "tsc --sourceMap true --declarationMap true",
     "build": "tsc",
     "test": "echo \"Error: no test specified\" && exit 1"
diff --git a/src/index.ts b/src/index.ts
index f423bb8..33b639f 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -7,7 +7,7 @@
  */

 const main = () => {
-    console.log("Hello world!!!")
+    console.log("Are you ok?")
 }

提交代码:

* `git add -A`
* `git commit -m "chore: 添加自动重启配置"`

7 代码错误检查功能Eslint

7.1 eslint是什么？为什么要用eslint?

eslint是一个代码检查工具，它能识别代码中的错误。并帮助开发者修复错误。就是这是一款有效防止开发者犯错提高代码稳定性的工具。 而开发者也是人，人就一定会犯错，有这样的工具，没理由不用它吧？

7.2 安装Eslint

$ pnpm create @eslint/config

✔ How would you like to use ESLint? · style
✔ What type of modules does your project use? · esm
✔ Which framework does your project use? · none
✔ Does your project use TypeScript? · No / Yes
✔ Where does your code run? · browser
✔ How would you like to define a style for your project? · prompt
✔ What format do you want your config file to be in? · JavaScript
✔ What style of indentation do you use? · tab
✔ What quotes do you use for strings? · double
✔ What line endings do you use? · unix
✔ Do you require semicolons? · No / Yes
Local ESLint installation not found.
The config that you've selected requires the following dependencies:

// ...

安装完成后会在项目根目录下生成eslint的配置文件.eslintrc.js。

.eslintrc.js

module.exports = {
    "env": {
        "browser": true,
        "es2021": true,
        "node": true
    },
    "extends": [
        "eslint:recommended",
        "plugin:@typescript-eslint/recommended"
    ],
    "overrides": [
    ],
    "parser": "@typescript-eslint/parser",
    "parserOptions": {
        "ecmaVersion": "latest",
        "sourceType": "module"
    },
    "plugins": [
        "@typescript-eslint"
    ],
    "rules": {
        "indent": [
            "error",
            2
        ],
        "linebreak-style": [
            "error",
            "unix"
        ],
        "quotes": [
            "error",
            "double"
        ],
        "semi": [
            "error",
            "always"
        ]
    }
};

7.3 配置eslint的修复到开发模式中

eslint有修复功能，用于自动修复代码的错误，这样有些代码出错时是可以自动修复，减少工作量。

配置package.json

// ...
  "scripts": {
    "dev": "nodemon --exec \"npm run lint:fix && npm run dev:build && npm run start\"",
    "start": "node dist/index.js",
    "lint:fix": "eslint 'src/**/*.ts' --fix",
    "build": "tsc",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
// ...

这样配置后，每当代码保存后，就会自动用eslint去检查代码并自动修复。

7.4 提交代码

本次代码变动

diff --git a/package.json b/package.json
index edce3cb..25fb2f9 100644
--- a/package.json
+++ b/package.json
@@ -4,8 +4,9 @@
   "description": "",
   "main": "dist/index.js",
   "scripts": {
-    "dev": "nodemon --exec \"npm run dev:build && npm run start\"",
+    "dev": "nodemon --exec \"npm run lint:fix && npm run dev:build && npm run start\"",
     "start": "node dist/index.js",
+    "lint:fix": "eslint 'src/**/*.ts' --fix",
     "dev:build": "tsc --sourceMap true --declarationMap true",
     "build": "tsc",
     "test": "echo \"Error: no test specified\" && exit 1"
@@ -13,6 +14,9 @@
   "author": "",
   "license": "ISC",
   "devDependencies": {
+    "@typescript-eslint/eslint-plugin": "^5.44.0",
+    "@typescript-eslint/parser": "^5.44.0",
+    "eslint": "^8.28.0",
     "nodemon": "^2.0.20",
     "typescript": "^4.9.3"
   }
diff --git a/src/index.ts b/src/index.ts
index 33b639f..f97a4db 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -7,7 +7,7 @@
  */

 const main = () => {
-    console.log("Are you ok?")
-}
+       console.log("Are you ok?");
+};

-export default main()
\ No newline at end of file
+export default main;

提交代码

$git commit -m 'chore: 添加eslint功能'

8 代码自动格式化--prettier

为什么要用代码格式化？保持代码风格的统一很重要，特别是在团队合作的下，每个人的代码风格都不同，这样很可能导致代码的 不规范,可读性变差. 所以代码的风格的统一化很重要。

8.1 安装prettier

$ pnpm install --save-dev --save-exact prettier

8.2 添加格式化配置和忽略配置

格式化配置文件.perttierrc.json

{
  "arrowParens": "always",
  "bracketSameLine": false,
  "bracketSpacing": true,
  "embeddedLanguageFormatting": "auto",
  "htmlWhitespaceSensitivity": "css",
  "insertPragma": false,
  "jsxSingleQuote": false,
  "printWidth": 80,
  "proseWrap": "preserve",
  "quoteProps": "as-needed",
  "requirePragma": false,
  "semi": true,
  "singleQuote": false,
  "tabWidth": 2,
  "trailingComma": "es5",
  "useTabs": false,
  "vueIndentScriptAndStyle": false
}

node_modules
dist
.git
.idea
.pnpm-debug.log
pnpm-lock.yaml

8.3 解决eslint与prettier冲突的规则

$ pnpm install --save-dev eslint-config-prettier

修复.eslintrc.js

// ...

  extends: [
    "eslint:recommended",
    "plugin:@typescript-eslint/recommended",
    "prettier"
 ],
// ...

8.4 开发模式下自动格式化

package.json

// ...
"scripts": {
"dev": "nodemon --exec \"npm run prettier && npm run lint:fix && npm run dev:build && npm run start\"",
"start": "node dist/index.js",
"lint:fix": "eslint 'src/**/*.ts' --fix",
"dev:build": "tsc --sourceMap true --declarationMap true",
"prettier": "prettier --write .",
"build": "tsc",
"test": "echo \"Error: no test specified\" && exit 1"
},
// ...

然后当运行pnpm run dev后，每当保存代码时，就会自动格式化代码格式。

监听代码变动时，自动格式化代码

 $ pnpm run dev

    > dynamicdns@0.0.1 dev /Users/wuchuheng/Desktop/myprojects/wuchuheng/npm/dynamicDNS
    > nodemon --exec "npm run prettier && npm run lint:fix && npm run dev:build && npm run start"

    [nodemon] 2.0.20
    [nodemon] to restart at any time, enter `rs`
    [nodemon] watching path(s): src/**
    [nodemon] watching extensions: ts
    [nodemon] starting `npm run prettier && npm run lint:fix && npm run dev:build && npm run start`

    > dynamicdns@0.0.1 prettier
    > prettier --write .

    .eslintrc.js 68ms
    .prettierrc.json 6ms
    nodemon.json 3ms
    package.json 3ms
    src/index.ts 363ms
    tsconfig.json 14ms

    > dynamicdns@0.0.1 lint:fix
    > eslint 'src/**/*.ts' --fix


    > dynamicdns@0.0.1 dev:build
    > tsc --sourceMap true --declarationMap true


    > dynamicdns@0.0.1 start
    > node dist/index.js

    [nodemon] clean exit - waiting for changes before restart

8.5 本次代码变动

本次代码变动

new file .prettierignore

node_modules
dist
.git
.idea
.pnpm-debug.log
pnpm-lock.yaml

new file .prettierrc.json

{
  "arrowParens": "always",
  "bracketSameLine": false,
  "bracketSpacing": true,
  "embeddedLanguageFormatting": "auto",
  "htmlWhitespaceSensitivity": "css",
  "insertPragma": false,
  "jsxSingleQuote": false,
  "printWidth": 80,
  "proseWrap": "preserve",
  "quoteProps": "as-needed",
  "requirePragma": false,
  "semi": true,
  "singleQuote": false,
  "tabWidth": 2,
  "trailingComma": "es5",
  "useTabs": false,
  "vueIndentScriptAndStyle": false
}

changed files

diff --git a/.eslintrc.js b/.eslintrc.js
index dc5c0b4..57ab1b4 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -1,39 +1,25 @@
 module.exports = {
-       "env": {
-               "browser": true,
-               "es2021": true,
-               "node": true
-       },
-       "extends": [
-               "eslint:recommended",
-               "plugin:@typescript-eslint/recommended"
-       ],
-       "overrides": [
-       ],
-       "parser": "@typescript-eslint/parser",
-       "parserOptions": {
-               "ecmaVersion": "latest",
-               "sourceType": "module"
-       },
-       "plugins": [
-               "@typescript-eslint"
-       ],
-       "rules": {
-               "indent": [
-                       "error",
-                       "tab"
-               ],
-               "linebreak-style": [
-                       "error",
-                       "unix"
-               ],
-               "quotes": [
-                       "error",
-                       "double"
-               ],
-               "semi": [
-                       "error",
-                       "always"
-               ]
-       }
+  env: {
+    browser: true,
+    es2021: true,
+    node: true,
+  },
+  extends: [
+    "eslint:recommended",
+    "plugin:@typescript-eslint/recommended",
+    "prettier",
+  ],
+  overrides: [],
+  parser: "@typescript-eslint/parser",
+  parserOptions: {
+    ecmaVersion: "latest",
+    sourceType: "module",
+  },
+  plugins: ["@typescript-eslint"],
+  rules: {
+    indent: ["error", 2],
+    "linebreak-style": ["error", "unix"],
+    quotes: ["error", "double"],
+    semi: ["error", "always"],
+  },
 };
diff --git a/.prettierignore b/.prettierignore
index e69de29..c65f4f1 100644
--- a/.prettierignore
+++ b/.prettierignore
@@ -0,0 +1,6 @@
+node_modules
+dist
+.git
+.idea
+.pnpm-debug.log
+pnpm-lock.yaml
diff --git a/.prettierrc.json b/.prettierrc.json
index e69de29..d0a82a7 100644
--- a/.prettierrc.json
+++ b/.prettierrc.json
@@ -0,0 +1,19 @@
+{
+  "arrowParens": "always",
+  "bracketSameLine": false,
+  "bracketSpacing": true,
+  "embeddedLanguageFormatting": "auto",
+  "htmlWhitespaceSensitivity": "css",
+  "insertPragma": false,
+  "jsxSingleQuote": false,
+  "printWidth": 80,
+  "proseWrap": "preserve",
+  "quoteProps": "as-needed",
+  "requirePragma": false,
+  "semi": true,
+  "singleQuote": false,
+  "tabWidth": 2,
+  "trailingComma": "es5",
+  "useTabs": false,
+  "vueIndentScriptAndStyle": false
+}
diff --git a/nodemon.json b/nodemon.json
index 59b6cda..657f5aa 100644
--- a/nodemon.json
+++ b/nodemon.json
@@ -1,4 +1,4 @@
 {
   "watch": ["src/**"],
   "ext": "ts"
-}
\ No newline at end of file
+}
diff --git a/package.json b/package.json
index 25fb2f9..f64f1c4 100644
--- a/package.json
+++ b/package.json
@@ -4,10 +4,11 @@
   "description": "",
   "main": "dist/index.js",
   "scripts": {
-    "dev": "nodemon --exec \"npm run lint:fix && npm run dev:build && npm run start\"",
+    "dev": "nodemon --exec \"npm run prettier && npm run lint:fix && npm run dev:build && npm run start\"",
     "start": "node dist/index.js",
     "lint:fix": "eslint 'src/**/*.ts' --fix",
     "dev:build": "tsc --sourceMap true --declarationMap true",
+    "prettier": "prettier --write .",
     "build": "tsc",
     "test": "echo \"Error: no test specified\" && exit 1"
   },
@@ -17,7 +18,9 @@
     "@typescript-eslint/eslint-plugin": "^5.44.0",
     "@typescript-eslint/parser": "^5.44.0",
     "eslint": "^8.28.0",
+    "eslint-config-prettier": "^8.5.0",
     "nodemon": "^2.0.20",
+    "prettier": "2.7.1",
     "typescript": "^4.9.3"
   }
 }
diff --git a/src/index.ts b/src/index.ts
index f97a4db..e776ee5 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -7,7 +7,7 @@
  */

 const main = () => {
-       console.log("Are you ok?");
+  console.log("Are you ok?");
 };

 export default main;
diff --git a/tsconfig.json b/tsconfig.json
index 1eb8c87..b7d95a2 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -4,15 +4,12 @@
     "module": "commonjs", // js的导出模块类型
     "declaration": true, // 编译导出包含类型文件
     "outDir": "dist", // 编译后导出的目录
-    "esModuleInterop": true,                             /* Emit additional JavaScript to ease support for importing CommonJS modules. This enables 'allowSyntheticDefaultImports' for type compatibility. */
+    "esModuleInterop": true /* Emit additional JavaScript to ease support for importing CommonJS modules. This enables 'allowSyntheticDefaultImports' for type compatibility. */,
     "rootDir": "src", // 要编译的代码开始目录
-    "forceConsistentCasingInFileNames": true,            /* Ensure that casing is correct in imports. */
-    "strict": true,                                      /* Enable all strict type-checking options. */
-    "skipLibCheck": true                                 /* Skip type checking all .d.ts files. */
+    "forceConsistentCasingInFileNames": true /* Ensure that casing is correct in imports. */,
+    "strict": true /* Enable all strict type-checking options. */,
+    "skipLibCheck": true /* Skip type checking all .d.ts files. */
   },
   // ts编译时忽略的文件
-  "exclude": [
-    "node_modules",
-    "dist"
-  ]
+  "exclude": ["node_modules", "dist"]
 }

提交代码

$ git add -A
$ git commit -m 'chore: 添加代码自动格式化'

9 小结

一个好的软件工程需要好的开发体验，本文从开发者角度出发，解决，自动化编译,自动化重启，自动化检查，自动化代码格式化，这 些方面来保证代码的稳定性和开发的统一性。

10 项目源码

Source code

11. Create a express with typescript in cmd.

$ pnpx @wuchuheng/express my-express-app

11 参考资料

• eslint
• prettierrc