Esbuild causing bundle breakage when applied twice to the same bundle

[alan-agius4]

In certain peculiar cases, running esbuild on a bundle that has already been processed by esbuild can lead to the bundle breaking. This issue is a simplified illustration of the problem described in detail at cloudflare/workers-sdk#5263.

Notice the I function invocation in handleNavigationRequest which in the output is actually changed to reference the local class t.

entry.js

import { b as I } from "./file.mjs";

var classSomething = (() => {
  let t2 = class t {
    handleNavigationRequest(r) {
      return I()
    }
  };

  return t2;
})();

export { classSomething };

file.mjs

var t = function() {};

export { t as b };

output

// file.mjs
var t = function() {
};

// entry.js
var classSomething = /* @__PURE__ */ (() => {
  let t2 = class t {
    handleNavigationRequest(r) {
      return t();
    }
  };
  return t2;
})();
export {
  classSomething
};

Reproduction: here

Esbuild version: 0.20.2