Add ReadOnlyProperty

[pixelzoom]

This work was started without an issue, but seemed like we should have one, so here it is.

[pixelzoom]

@jonathanolson commited ReadOnlyProperty in the above commit, but there were some problems. See Slack discussion below.

Slack

Jonathan Olson 6:09 PM
Added ReadOnlyProperty, see 2dc362b ...

Chris Malley 6:44 PM
Boo hoo. I still can’t pass a ReadOnlyProperty to addLinkedElement( element: PhetioObject, options?: any): void. For example FocalPointNode.ts constructor param pointProperty.

Jonathan Olson 6:47 PM
Hmm, checking

Chris Malley 6:47 PM
addLinkedElement has been my pain point.

Jonathan Olson 6:48 PM
Reproduced

Jonathan Olson 6:50 PM
It's expecting... private/protected things?

Chris Malley 6:51
The fields that TS identifies as missing are protected/private?

Jonathan Olson 6:51 PM
Yeah my ReadOnlyProperty is somehow very broken

Chris Malley 6:53 PM
I created phetsims/geometric-optics#359 to remind myself to fix things up in GO when this is working. No rush.

Jonathan Olson 7:12 PM
TypeScript is... killing me again. Not sure if this is possible. Omit (and the extends/infer it's based on) seems to convert it away from an interface into a type that loses the protected/private info

[pixelzoom]

In phetsims/scenery-phet#726 (comment), @jonathanolson said:

ReadOnlyProperty is buggy, and not ready for use. I'm not sure it's possible to make it work. Perhaps I should remove it?

Yes, probably so.

[pixelzoom]

It's been 30 days since we discussed deleting ReadOnlyProperty . If ReadOnlyProperty is not going to be fixed, can we please remove it? More than once, I've accidentally ended up with ReadOnlyProperty when I wanted IReadOnlyProperty.

[samreid]

I'll work on removing it momentarily.

[samreid]

Removed. Type checking and linting is passing locally. There were no usages. @pixelzoom can you please review?

[pixelzoom]

👍🏻