Importing a mocked ESM module dynamically will throw an error in node 16.17.0 #498

adamraine · 2022-08-30T23:42:20Z

Description

Importing a mocked ESM module dynamically will throw an error in node 16.17.0 but not 16.16.0.

Issue

Mocking an esm module will result on an error

Environment

node -v output: v16.17.0
yarn --version output: 1.22.19
yarn list testdouble version: testdouble@3.16.5

Code-fenced Examples

❯❯❯ node --loader=testdouble script.js
(node:83826) ExperimentalWarning: Custom ESM Loaders is an experimental feature. This feature could change at any time
(Use `node --trace-warnings ...` to show where the warning was created)
(node:83826) DeprecationWarning: Obsolete loader hook(s) supplied and will be ignored: getFormat, getSource
node:internal/errors:477
    ErrorCaptureStackTrace(err);
    ^

Error [ERR_LOADER_CHAIN_INCOMPLETE]: "testdouble 'load'" did not call the next hook in its chain and did not explicitly signal a short circuit. If this is intentional, include `shortCircuit: true` in the hook's return.
    at new NodeError (node:internal/errors:387:5)
    at ESMLoader.load (node:internal/modules/esm/loader:616:13)
    at async ESMLoader.moduleProvider (node:internal/modules/esm/loader:464:11)
    at async link (node:internal/modules/esm/module_job:67:21) {
  code: 'ERR_LOADER_CHAIN_INCOMPLETE'
}

import * as td from 'testdouble';
await td.replaceEsm('fs', {});
await import('fs');

The text was updated successfully, but these errors were encountered:

searls · 2022-08-31T18:13:30Z

I haven't used td.replaceEsm in earnest, but it would be unusual to import a mocked module from the same code listing.

I would have expected:

import * as td from 'testdouble';
const fs = await td.replaceEsm('fs', {});

And then the subject under test would be loaded and it would in turn import the mocked module. As per this example in the docs.

As a result I'm not sure this is supported. Can you elaborate if it seems like I'm off-base?

adamraine · 2022-08-31T18:26:16Z

I haven't used td.replaceEsm in earnest, but it would be unusual to import a mocked module from the same code listing.

Perhaps the minimum repro is too minimum in this case. The same thing happens if the dynamic import occurs further down the dependency tree:

import * as td from 'testdouble';
await td.replaceEsm('fs', {});
await import('./test-module.js');

test-module.js:

await import('fs');

In this situation it doesn't make sense to use the return value of td.replaceEsm because the mocked module needs to be injected into test-module.js.

connorjclark · 2022-09-07T18:44:24Z

The bug actually came from usage of my fork, not qubbile mainline. Sorry about that. This was fixed by testdouble/quibble#74 – simply rebasing the latest code fixed it for us.

- See testdouble/testdouble.js#498

adamraine mentioned this issue Sep 7, 2022

fix CI unit tests on Node 16.x and 18 GoogleChrome/lighthouse#14345

Closed

connorjclark mentioned this issue Sep 7, 2022

deps: update quibble fork to work with new loader api GoogleChrome/lighthouse#14366

Merged

adamraine closed this as completed Sep 7, 2022

eoinsha added a commit to fourTheorem/slic-starter that referenced this issue Nov 15, 2022

fix: support Node 16.17 or later with testdouble/quibble fix

a571c82

- See testdouble/testdouble.js#498

eoinsha added a commit to fourTheorem/slic-starter that referenced this issue Oct 2, 2023

fix: support Node 16.17 or later with testdouble/quibble fix

ff28ba6

- See testdouble/testdouble.js#498

Importing a mocked ESM module dynamically will throw an error in node 16.17.0 #498

Importing a mocked ESM module dynamically will throw an error in node 16.17.0 #498

adamraine commented Aug 30, 2022

searls commented Aug 31, 2022

adamraine commented Aug 31, 2022

connorjclark commented Sep 7, 2022 •

edited

Importing a mocked ESM module dynamically will throw an error in node 16.17.0 #498

Importing a mocked ESM module dynamically will throw an error in node 16.17.0 #498

Comments

adamraine commented Aug 30, 2022

Description

Issue

Environment

Code-fenced Examples

searls commented Aug 31, 2022

adamraine commented Aug 31, 2022

connorjclark commented Sep 7, 2022 • edited

connorjclark commented Sep 7, 2022 •

edited