Reproduction link or steps

reproduction: https://stackblitz.com/github/hi-ogawa/reproductions/tree/main/rolldown-external-import?file=README.md

input

• entry.js

import "./dep.js";
import "@rolldown/test-dep-external";  // this is externalized

• dep.js

console.log("[importing dep.js]");

• @rolldown/test-dep-external

console.log("[importing test-dep-external]");

output

• with strictExecutionOrder: false

import "@rolldown/test-dep-external";

//#region src/dep.js
console.log("[importing dep.js]");

• with strictExecutionOrder: true

import "@rolldown/test-dep-external";

//#region rolldown:runtime
var __getOwnPropNames = Object.getOwnPropertyNames;
var __esm = (fn, res) => function() {
	return fn && (res = (0, fn[__getOwnPropNames(fn)[0]])(fn = 0)), res;
};

//#endregion
//#region src/dep.js
var init_dep = __esm({ "src/dep.js"() {
	console.log("[importing dep.js]");
} });

//#endregion
//#region src/entry.js
var init_entry = __esm({ "src/entry.js"() {
	init_dep();
} });

//#endregion
init_entry();

What is expected?

Executed like original esm

$ node src/entry.js
[importing dep.js]
[importing test-dep-external]

What is actually happening?

$ pnpm build
$ node dist/entry.js
[importing test-dep-external]
[importing dep.js]

System Info

System:
    OS: Linux 5.0 undefined
    CPU: (8) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
    Memory: 0 Bytes / 0 Bytes
    Shell: 1.0 - /bin/jsh
  Binaries:
    Node: 18.20.3 - /usr/local/bin/node
    Yarn: 1.22.19 - /usr/local/bin/yarn
    npm: 10.2.3 - /usr/local/bin/npm
    pnpm: 8.15.6 - /usr/local/bin/pnpm
  npmPackages:
    rolldown: 0.15.0-snapshot-3cea4f5-20241211003613 => 0.15.0-snapshot-3cea4f5-20241211003613

Any additional comments?

I wrote a comparison with other bundlers and their output in https://github.com/hi-ogawa/reproductions/tree/main/rolldown-external-import
What webpack (and thus rspack, turbopack, next.js) are doing is to effectively rewrite static external import into a dynamic import and handle it as async module and top-level-await.
Vite SSR does something similar, so this example turns out to work (though we know Vite SSR's evaluation is not so robust in general).

As a side note, I had experimented with next.js/turbopack initially and their external handling might have one caveat (thought probably reasonable). I wrote an example here about what happens when indirect dependency is externalized https://github.com/hi-ogawa/reproductions/tree/main/next-external-import