Add latest typescript to CodeSandbox devDependencies

[mike-000]

While adding an empty .babelrc in #14419 prevented unwanted transpiling by CodeSandbox after #14279 it appears that the default parcel template in CodeSandbox uses an old version of Babel for parsing the application JavaScript and as noted in #14445 (comment) modern syntax such as optional chaining (which would have been useful in the example in #14582 (comment)) is rejected. If the unneeded '@babel/core': 'latest', removed from live example by #14279 is injected into the package.json supplied to CodeSandbox it fixes the problem. This is an external use so it does not need to be an OpenLayers dependency.

[github-actions]

📦 Preview the website for this branch here: https://deploy-preview-14589--ol-site.netlify.app/.

[tschaub]

It looks like a few alternatives to adding babel would be to

• use a Cloud Sandbox (e.g. https://codesandbox.io/p/sandbox/mutable-currying-f98wu6?file=%2Fmain.js)
• avoid the use of optional chaining (only used in the icon-width.js example currently)
• add Typescript as a sandbox dev dependency instead of Babel

I'm not sure how much would have to change if we used Cloud Sandboxes instead of Web Sandboxes (I think this is the term they use to differentiate). Also don't know if Cloud Sandboxes will provide a better or worse experience for people trying to edit our examples (not sure if they will be faster or slower, etc.).

It feels pretty easy to just change the icon-width.js example to avoid using optional chaining. But there could be other things that break the CodeSandbox/Parcel parser as well.

I don't have a strong preference regarding Typescript or Babel, but Typescript feels closer to being a first class dev dependency of ours, so I might choose that over Babel.

[mike-000]

But there could be other things that break the CodeSandbox/Parcel parser as well.

I looks like syntax changes in ES2018 such as let { x, y, ...z } = { x: 1, y: 2, a: 3, b: 4 }; (or as used in https://openlayers.org/en/latest/examples/clusters-dynamic.html) and later ES versions all cause problems.

Adding "typescript": "latest" as a fix works equally as well as "@babel/core": "latest".

[tschaub]

Thanks, @mike-000

[jahow]

thanks for taking care of this!