esbuild: esbuild runtime introduces `exports` and `modules` which is not match with default browser env

esbuild version: 0.14.12

When I apply esbuild to following code (derived from CodeMirror)

(function() {
    if (typeof exports == "object" && typeof module == "object") // CommonJS
    { console.log("CommonJS"); }
    else if (typeof define == "function" && define.amd) // AMD
    { console.log("AMD"); }
    else // Plain browser env
    { console.log("browser") ;}
}());

like esbuild --bundle a.js, then esbuild generates following code

(() => {
  var __getOwnPropNames = Object.getOwnPropertyNames;
  var __commonJS = (cb, mod) => function __require() {
    return mod || (0, cb[__getOwnPropNames(cb)[0]])((mod = { exports: {} }).exports, mod), mod.exports;
  };

  // a.js
  var require_a = __commonJS({
    "a.js"(exports, module) {
      (function() {
        if (typeof exports == "object" && typeof module == "object") {
          console.log("CommonJS");
        } else if (typeof define == "function" && define.amd) {
          console.log("AMD");
        } else {
          console.log("browser");
        }
      })();
    }
  });
  require_a();
})();

In browser, original code shows browser while generated code shows CommonJS.

And I’m wondering whether esbuild can make exports/module variables match with browser env.