package.json type module

Describe the bug Using the new (but still exprimental) node esm loading mechanism does not work with the current version of ol’s package.json.

To Reproduce

1. npm i ol
2. in index.js import { createXYZ } from 'ol/tilegrid.js';
3. node --experimental-modules index.js gives the following error:

Cannot use import statement outside a module

Expected behavior The module should be imported.

Fix Add "type": "module" to the package.json

[tschaub]

I decided to resurrect an old branch that converted our package to "type": "module" for the whole repo - not just for the published package. This wasn’t working that well with Node < 14 (when I last tried it) but is working better now.

You can npm install ol@module to try it out. Here is a draft PR for the ol-parcel project: openlayers/ol-parcel#1.

There is still work to do to convert the test utilities (and probably doc things). I’ll migrate #12241 out of draft state when that is done.

[ahocevar]

We have evaluated this and decided to wait with adding "type": "module" until ES modules are stable in Node (perhaps Node 14). In the meantime, you can use esm to make OpenLayers work in a Node environment.