为此，我通常会使用具有“Tree-shaking”功能的捆绑器，例如https://esbuild.github.io/api/#tree-shaking或https://parceljs.org/features/scope-hoisting/
在esbuild中，这相对容易：https://esbuild.github.io/api/#define
您定义了debug变量 *，捆绑器会自动删除从未执行过的代码分支。

• 尽管您应该使用另一个名称，如DEBUG_YOUR_PACKAGE_NAME，这样不太可能与依赖项中的代码冲突）

信用：感谢Simon Lax指示我专注于bundler部分...
我正在使用rollup.js，带有plugin-strip插件。然后，用我的rollup.config.js中的一个开关，我可以启用/禁用"transpile away"

// src/main.ts
import fs from "fs";
class Service {
  expensive(res = ""): string {
    for (let i = 0; i < 1000; i++) res += i;
    return res;
  }
  normal(): string {
    return "Hi mom!";
  }
}

class Logger {
  public static log<T>(statement: T): T | undefined {
    console.log(statement);
    return statement;
  }
}

const s = new Service();

Logger.log(`${s.expensive()}`);

console.log(s.normal());

// and I can even use it in different situations, which usually expect the output.
fs.writeFileSync(
  "/tmp/abc",
  Logger.log(
    "not printed to screen nor to file but I wont have runtime exceptions, because TS hints me to catch the undefined case with the null'ish concealing",
  ) ?? "",
);

// rollup.config.js
import typescript from "@rollup/plugin-typescript";
import strip from "@rollup/plugin-strip";

export default [
  {
    external: ["fs"],
    input: ["src/main.ts"],
    output: {
      dir: "dist",
      format: "es",
    },
    strictDeprecations: true,
    plugins: [
      strip({
        include: ["**/*.ts"],
        functions: process.env.DEBUG ? [] : ["logger.log"],
      }),
      typescript(),
    ],
  },
];

// package.json
 
 "type": "module",
  "scripts": {
    "bundle": "rollup --config rollup.config.js"
  },
  "devDependencies": {
    "@rollup/plugin-strip": "^3.0.2",
    "@rollup/plugin-typescript": "^11.0.0",
    "rollup": "^3.15.0",
    "typescript": "^4.9.5"
  },

那么在运行npm run bundle之后，它将创建剥离的版本

// dist/main.js
import fs from 'fs';

class Service {
    expensive(res = "") {
        for (let i = 0; i < 1000; i++)
            res += i;
        return res;
    }
    normal() {
        return "Hi mom!";
    }
}
const s = new Service();
console.log(s.normal());
// and I can even use it in different situations, which usually expect the output.
fs.writeFileSync("/tmp/abc", "");

并运行DEBUG=1 npm run bundle，它将创建完整版本

// dist/main.js
import fs from 'fs';

class Service {
    expensive(res = "") {
        for (let i = 0; i < 1000; i++)
            res += i;
        return res;
    }
    normal() {
        return "Hi mom!";
    }
}
class Logger {
    static log(statement) {
        console.log(statement);
        return statement;
    }
}
const s = new Service();
Logger.log(`${s.expensive()}`);
console.log(s.normal());
// and I can even use it in different situations, which usually expect the output.
fs.writeFileSync("/tmp/abc", Logger.log("not printed to screen nor to file but I wont have runtime exceptions, because TS hints me to catch the undefined case with the null'ish concealing") ?? "");

(for完整性，我的tsconfig.json）

// tsconfig.json
{
  "compilerOptions": {
    "outDir": "dist",
    "target": "ES2022",
    "module": "ES2022",
    "moduleResolution": "node",
    "strict": true,
    "esModuleInterop": true,
    "baseUrl": "."
  },
  "ts-node": {
    "transpileOnly": true
  }
}