node compat: Dynamic import leads to missing globals

[marvinhagemeister]

A dynamic import that is not statically analysable breaks npm detection which leads to node globals missing.

This was originally reported on the Fresh repo denoland/fresh#1577 . In Fresh the dev.ts entry point calls a dynamic import where the specifier is not statically analysable:

export async function dev(base: string, entrypoint: string) {
  entrypoint = new URL(entrypoint, base).href;
  // ...
  await import(entrypoint);
}

Reproduction repo: https://github.com/marvinhagemeister/deno-npm-bug

Steps to reproduce

1. Clone https://github.com/marvinhagemeister/deno-npm-bug
2. Run deno run -A foo.ts

[bartlomieju]

CC @lucacasonato

[bartlomieju]

The contents of the file are:

"use strict";
/**
 * Node.js implementation of browser `btoa` function.
 *
 * @packageDocumentation
 * @internal
 */
Object.defineProperty(exports, "__esModule", { value: true });
exports.base64Encode = void 0;
/**
 * @internal
 */
function base64Encode(str) {
    return Buffer.from(str).toString("base64");
}
exports.base64Encode = base64Encode;
//# sourceMappingURL=btoa.js.map⏎

I think this might be the limitation Luca mentioned, but I'm not sure.

[lucacasonato]

No, this doesn't look related. Please bisect if you think it's related to my globals PR. I think what is happening is that internals.node.initialize() is either not being called, or there is a race. Can you find that out?

I am about 98% confident this bug was already present when I implemented npm: support in Fresh. I reported it to @dsherret back then.

[bartlomieju]

Ah, thanks for the pointer, that's probably related to #15826 then.

[loynoir]

Minimal reproduce.

Seems like something depends on simple AST, actually.

But should implement as AST-independent.

OK when 'id'

==> foo.test.ts <==
import kleur from 'npm:kleur@3.0.0'

Deno.test('x', () => {
  console.log({ kleur })
  kleur.red('1x')
})

==> test.ts <==
await import('./foo.test.ts')

Error when `id`

==> foo.test.ts <==
import kleur from 'npm:kleur@3.0.0'

Deno.test('x', () => {
  console.log({ kleur })
  kleur.red('1x')
})

==> test.ts <==
await import(`./foo.test.ts`)

[williamhorning]

I've been able to reproduce this this with both Deno 1.35.3 and 1.36.0 and found that the globals for Node packages are set right if you statically import those packages before they are dynamically imported. williamhorning/deno-dynamic-import-globals has an example of this using undici.

[davideperozzi]

@williamhorning Thank you! I've been looking for a temporary fix. Importing any npm module before the dynamic import did the trick. So I'm basically doing import 'npm:is-number' (just using it, becaus it's small) to force the globals to load.

[bartlomieju]

FYI you should be able to work-around the problem by importing any built-in node: module, no need to import npm: libraries.