Support for importing ES modules

[Al Marks]

Node now supports ES modules, but there doesn't seem to be a way to import them from a ttypescript config.

https://nodejs.org/api/esm.html

A CommonJS module can import an ES module like this:

const esModule = await import('some-es-module');

ttypescript could know to use import with a new plugin configuration option (e.g. "module": true).

Or to be more automatic, it could follow the Node rules which are to 1) check it ends with .mjs and if so import as a module, 2) check if it ends with .cjs and if so import as CommonJS, 3) otherwise check the package's package.json for "type": "module".

[Jeff Hall]

I have a project that depends on TTypescript 1.5.13. I can build the project with ttsc when my project uses Typescript 4.3.5. However if I upgrade to Typescript 4.5.2, this error is thrown:

TypeError: Cannot read property 'impliedNodeFormat' of undefined

Does this enhancement address that issue, or I have encountered an unreported bug?

[cevek]

Hello @robojeff. Do you have some repro?

[Colin Kennedy]

@robojeff You using ts-transform-paths? I found this bug report after trying to upgrade my own project: zerkalica/zerollup#37