Add support for dynamic imports

[Abrifq]

Using Visual Studio Code 1.43.2

Extension: "dbaeumer.jshint" using global installation of jshint from npm

JSHint Installed: 2.11.0@npm

Expected Behaviour: Recognize import() as a function.

Actual Behaviour

JSHint doesn't recognize

import("module/path.mjs") //Returns Promise of export object

as a function and throws E053 and E021.

This function is used in importing modules for scripts doesn't end with ".mjs".
More info about can be seen in this MDN page.

I don't know if this function is in proposals, it just works in major browsers (Firefox,Chrome, etc.) and node.js.

Config Values

Not using .jshintrc file, using a global extension setting. ```js { "jshint.lintHTML": true, "jshint.options": { "esversion": 9, "varstmt": true, "unused": true, "undef": true, "singleGroups": true, "eqeqeq": true, "freeze": true, "lastsemic": true, "leanswitch": true, "latedef": true, "maxdepth": 4, "noreturnawait": true, "nonbsp": true, "noarg": true, "maxparams": 3, "maxerr": 10, "maxcomplexity": 15, "node": true } } ```

[jugglinmike]

Thanks for the report! We haven't implemented support for dynamic imports, but we plan to (it definitely satisfies our policy on new language features). That makes this more of a feature request than a bug report, so I've modified the issue's title a bit--hope you don't mind.

If you (or anyone else) would like to try implementing this, then I'd gladly give guidance!

[almercier]

@jugglinmike Considering this is an es2020 proposal, how would you envision somone be able to toggle this feature? I'm assuming there would be an esversion: 11 which I assume would require all of the other es2020 proposals (nullish coalescing, optional chaining, etc...) to be supported as well.

I may look into implementing support for this specific proposal as it would help up quite a bit.

[jugglinmike]

esversion: 11 sounds about right to me, @almercier! Implementing all of the new language features is a big undertaking, and I wouldn't expect anyone to take all of that on by themselves. If you wanted to focus on the import expression, then we could tackle the other features in parallel (or publish a release with partial support for the new language edition).

[jugglinmike]

I've updated our submodule for Test262 so that we have better coverage for the new language features. I've also created a tracking branch for a new minor release; that's where we should land new features.

[jugglinmike]

JSHint version 2.13.0, released today, includes support for dynamic imports. Be sure to update your configuration to opt in to the new language feature via esversion: 11 or later.