error on set accessor without get accessor

[ajafff]

Fixes: #11596

[ajafff]

@typescript-bot test this

Edit: this seems to be restricted to members only?

[weswigham]

@ajafff Indeed - it is limited to repo owners and MS org members right now (it holds up a lot (1 of our 5 containers for around half an hour) of resources to run them and we don't want them triggered frivolously). @RyanCavanaugh I imagine you want to monitor the result, since you suggested it.

@typescript-bot test this

[typescript-bot]

Heya @weswigham, I've started to run the extended test suite on this PR at 0482b61. You can monitor the build here. It should now contribute to this PR's status checks.

[weswigham]

So this introduces errors into 10 of our RWC projects, with little added value - the setter-only objects mostly look like they're clearly written to actually be setter only - mostly membranes that do a little extra work on write. TBH, I personally have no problem with most of the usages in our RWC suite - they make a good argument for properly recognizing writeonly props.

[RyanCavanaugh]

Sounds like this needs to block on #21759 then?

[weswigham]

I'd say so, yeah. I don't think we can make it an error reasonably when people can't yet express the state in which a setter-only property is correct (and I think we'd still need a flag to opt-out of the new error - some projects like vscode seem to use setter-only stuff heavily and all those types probably won't get updated to writeonly at once).

[RyanCavanaugh]

Closing because this can't be merged unless #21759 happens (which is quite unlikely in the near future)