Jsdoc and IntelliSense does not work with imported modules with mjs extension

[henrik-jensen]

Does this issue occur when all extensions are disabled?: Yes

• VS Code Version: 1.62.3
• OS Version: Microsoft Windows [Version 10.0.19043.1348]

Steps to Reproduce:

1. Create folder minimal with package.json, index.js and foo_module.mjs and paste the code given later in this post to the respective files, or download zipped examples at end of post.
2. Hover the mouse over the add2 function in index.js for jsdoc popups and IntelliSense.

Result: Jsdoc and IntelliSense works with foo_module.js extension but not with foo_module.mjs extension.

Minimal working example (also attached at end of post)

package.json:

{ "type": "module" }

index.js:

import { add2 } from "./foo_module.mjs";
console.log(add2(5));

foo_module.mjs:

/**
 * Add 2 to input.
 * @param {number} input
 * @returns {number} - `input + 2`
 */
function add2(input) { return input+2; }
export {add2};

Results of hovering the mouse over add2:

• using import { add2 } from "./foo_module.mjs"; - No Jsdoc or IntelliSense:
  • 
• renaming to jsand using import { add2 } from "./foo_module.js"; - Jsdoc or IntelliSense works fine:
  • 

Note: both do output 7 as expected running the command $ node index.js.

Attached Minimal Working Examples:
minimal_mjs.zip using mjsextension
minimal_js.zip using jsextension

PS! Erroneously requested a reopen of typescript issue 27957 Support ".mjs" input files, thinking I was at the vscode repo, but maybe that issue is related?

[mjbvz]

Does this reproduce in the latest VS Code insiders build too?

Not sure if #27957 is a duplicate or not but any fix would be in the insiders build

[henrik-jensen]

Does this reproduce in the latest VS Code insiders build too?

Not sure if #27957 is a duplicate or not but any fix would be in the insiders build

Whatta you know? - seems fixed in insider 1.63.0.
Just installed a portable version of insider and it worked for .mjs extension.
Did the #27957 typescript inclusion of .mjs fix this issue?!!! (for the beta/insider!)

[frank-dspeed]

I do not expect this to be fixed before typescript-4.6 as the whole node12 nodenext support got scheduled to that version

#46452

[henrik-jensen]

Wait - is someone messing with my mind? - I'm pretty sure I opened this issue in the vscode repo and now it is back in the typescript repo?!!! What's happening? 🤨 😕🤪

[mjbvz]

Ok closing as likely fixed by TS 4.5 (which is included in current VS Code insiders builds)

I transferred the issue since this feature comes from TypeScript