const PAGE = "https://example.com/browser/toolkit/content/tests/browser/file_plugIn.html"; add_task(async function setup_test_preference() { setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Test Plug-in"); await SpecialPowers.pushPrefEnv({"set": [ ["media.useAudioChannelService.testing", true], ["media.block-autoplay-until-in-foreground", true], ]}); }); add_task(async function block_plug_in() { info("- open new background tab -"); let tab = BrowserTestUtils.addTab(window.gBrowser, "about:blank"); BrowserTestUtils.loadURI(tab.linkedBrowser, PAGE); await BrowserTestUtils.browserLoaded(tab.linkedBrowser); info("- tab should be blocked -"); await waitForTabBlockEvent(tab, true); info("- switch tab -"); await BrowserTestUtils.switchTab(window.gBrowser, tab); info("- tab should be resumed -"); await waitForTabBlockEvent(tab, false); info("- tab should be audible -"); await waitForTabPlayingEvent(tab, true); info("- remove tab -"); BrowserTestUtils.removeTab(tab); });