Updates dangerouslySetInnerHTML type so future TS will accept Trusted…

[lukewarlow]

…HTML automatically

Need to see if there's tests for this, and how to update them.

[coveralls]

coverage: 99.535%. remained the same
when pulling 428bace on lukewarlow:update-dangerouslySetInnerHTML-types-for-tt
into 5e18356 on preactjs:main.

[rschristian]

Thanks!

Just to expound: parseFromString should take A TrustedHTML or string instance defining HTML to be parsed., though TS has yet to update lib/dom.d.ts to account for this. The method here should in theory be future proof though and collect the correct types for .innerHTML when/if TS makes them available.

Quite crafty

[lukewarlow]

To provide a bit of extra detail we can't do something using innerHTML itself as that is currently a property but might become a getter setter pair and there's not a TS way to handle both those cases, nor does there seem to be a way to get the setter type, so this is a hack to get string | TrustedHTML in a workable way.