const ACTOR = "Bug1622420"; add_task(async function test() { let base = getRootDirectory(gTestPath).slice(0, -1); ChromeUtils.registerWindowActor(ACTOR, { allFrames: true, child: { esModuleURI: `${base}/Bug1622420Child.sys.mjs`, }, }); registerCleanupFunction(async () => { gBrowser.removeTab(tab); ChromeUtils.unregisterWindowActor(ACTOR); }); let tab = await BrowserTestUtils.openNewForegroundTab( gBrowser, // eslint-disable-next-line @microsoft/sdl/no-insecure-url "http://example.org/browser/docshell/test/browser/file_bug1622420.html" ); let childBC = tab.linkedBrowser.browsingContext.children[0]; let success = await childBC.currentWindowGlobal .getActor(ACTOR) .sendQuery("hasWindowContextForTopBC"); ok( success, "Should have a WindowContext for the top BrowsingContext in the process of a child BrowsingContext" ); });