window.opener should not be readonly

[lediur]

TypeScript Version: 2.8.1 (not present in 2.7.2)

Search Terms: opener (found #10379, but this was back in 2.0 / 2016), window readonly, set window opener to null typescript 2.8

Code

const newWindow = window.open(url);
if (newWindow) {
  newWindow.opener = null;
}

Expected behavior:
window.opener should be assignable to null for security reasons (e.g. microsoft/monaco-editor#601). Setting the noopener window feature only works in modern browsers.

Actual behavior:
window.opener is declared as readonly. This appears to be a 2.8 regression of #10379

Playground Link: here

Related Issues:
#10379

[mhegazy]

Should be fixed by microsoft/TypeScript-DOM-lib-generator#397. Fix should be included in 2.8.2 release.

[mhegazy]

reported earlier in #10379 (comment)

[lediur]

Oops, I saw that yesterday but for some reason didn't see the last comment. Good to know! Thanks for following up.