问为什么Webpack 5包括我未使用的TypeScript枚举出口，即使树摇动是启用的？

EN

export enum HueColors {
  "red"    = "hsl(0, 100%, 50%)",
  "orange" = "hsl(30, 100%, 50%)",
  // ...
  "pink"   = "hsl(330, 100%, 50%)",
}

export enum RGBExtended { /* ... */ }
export enum WebSafe { /* ... */ }

// package.json
{
  ...
  "main": "./index.js",
  "types": "./index.d.ts",
  "files": [
    "**/*.{js,ts, map}"
  ],
  "sideEffects": false,
  "scripts": {
    ...
    "build:dev": "cross-env NODE_ENV=development webpack --config config/webpack.config.js",
    "build": "cross-env NODE_ENV=production webpack --config config/webpack.config.js",
    ...
  },
  "babel": {
    "extends": "./config/.babelrc.json"
  },
  ...
  "devDependencies": {
    "@babel/core": "^7.14.8",
    "@babel/preset-env": "^7.14.8",
    "@types/jest": "^26.0.24",
    "@types/node": "^16.4.0",
    "@typescript-eslint/eslint-plugin": "^4.28.4",
    "@typescript-eslint/parser": "^4.28.4",
    "copy-webpack-plugin": "^9.0.1",
    "cross-env": "^7.0.3",
    "eslint": "^7.31.0",
    "eslint-plugin-jest": "^24.4.0",
    "jest": "^27.0.6",
    "prettier": "^2.3.2",
    "terser-webpack-plugin": "^5.1.4",
    "ts-jest": "^27.0.4",
    "ts-loader": "^9.2.4",
    "ts-node": "^10.1.0",
    "typedoc": "^0.21.4",
    "typescript": "^4.3.5",
    "webpack": "^5.46.0",
    "webpack-cli": "^4.7.2"
  }
}

// config/.babelrc.json
{
  "presets": [
    [
      "@babel/preset-env",
      {
        "targets": {
          "node": "current"
        },
        "modules": false
      }
    ]
  ]
}

// config/tsconfig.json
{
  "compilerOptions": {
    "target": "ES6",
    "module": "ES6",
    "lib": ["DOM", "DOM.Iterable", "ES2017"],
    "moduleResolution": "node", 
    "outDir": "../dist", 
    "noEmit": false,
    "declaration": true, 
    "strict": true,
    "esModuleInterop": true,
    "allowSyntheticDefaultImports": true,
    "removeComments": false,
    "forceConsistentCasingInFileNames": true,
    "noFallthroughCasesInSwitch": true
  },
  "include": ["../src"],
  "exclude": ["../node_modules", "../tests", "../coverage", "../src/debug.ts"]
}

// config/webpack.config.js

/* eslint-disable @typescript-eslint/no-var-requires */
const CopyPlugin = require("copy-webpack-plugin");

const path = require("path");

const basePath = path.resolve(__dirname, "../");

module.exports = {
  entry: path.join(basePath, "src", "index.ts"),
  mode: process.env.NODE_ENV,
  devtool: process.env.NODE_ENV === "production" ? "source-map" : false,
  module: {
    rules: [
      {
        test: /\.ts$/,
        loader: "ts-loader",
        options: {
          configFile: path.join(__dirname, "tsconfig.json")
        },
        exclude: /node_modules/
      }
    ]
  },
  plugins: [
    new CopyPlugin({
      patterns: [
        ... // not important for question
      ]
    })
  ],
  optimization: {
    minimize: process.env.NODE_ENV === "production",
    minimizer: [
      (compiler) => {
        const TerserPlugin = require("terser-webpack-plugin");
        new TerserPlugin({
          terserOptions: {
            ecma: 5,
            mangle: true,
            module: false
          }
        }).apply(compiler);
      }
    ],
    usedExports: true,
    sideEffects: true,
    innerGraph: true
  },
  stats: {
    usedExports: true,
    providedExports: true,
    env: true
  },
  resolve: {
    extensions: [".ts"]
  },
  output: {
    filename: "index.js",
    path: path.join(basePath, "dist"),
    library: "colormaster",
    libraryTarget: "umd",
    globalObject: "this",
    clean: true
  }
};

...
./src/enums/colors.ts 17.6 KiB [built] [code generated]
    [exports: HueColors, RGBExtended, WebSafe]
    [only some exports used: HueColors] // ← indicates that tree shaking should occur in production build
webpack 5.46.0 compiled successfully in 2368 ms

// dist/index.js → mode === development 

/***/ "./src/enums/colors.ts":
/*!*****************************!*\
  !*** ./src/enums/colors.ts ***!
  \*****************************/
/***/ ((__unused_webpack_module, __webpack_exports__, __webpack_require__) => {

/* harmony export */ __webpack_require__.d(__webpack_exports__, {
/* harmony export */   "HueColors": () => (/* binding */ HueColors)
/* harmony export */ });
/* unused harmony exports RGBExtended, WebSafe */ // ← indicates that tree shaking should occur in production
var HueColors;
(function (HueColors) {
    HueColors["red"] = "hsl(0, 100%, 50%)";
    ...
    HueColors["pink"] = "hsl(330, 100%, 50%)";
})(HueColors || (HueColors = {}));
var RGBExtended;
(function (RGBExtended) {
    RGBExtended["maroon"] = "rgb(128,0,0)";
    ...
    RGBExtended["white"] = "rgb(255,255,255)";
})(RGBExtended || (RGBExtended = {}));
var WebSafe;
(function (WebSafe) {
    WebSafe["#000000"] = "rgb(0,0,0)";
    ...
    WebSafe["#FFFFFF"] = "rgb(255,255,255)"; 
})(WebSafe || (WebSafe = {}));