add_task(async function() { let uri = "http://example.com/browser/layout/style/test/sourcemap_css.html"; info(`URI is ${uri}`); await BrowserTestUtils.withNewTab( { gBrowser, url: uri, }, async function(browser) { await SpecialPowers.spawn(browser, [], function() { let seenSheets = 0; for (let i = 0; i < content.document.styleSheets.length; ++i) { let sheet = content.document.styleSheets[i]; info(`Checking ${sheet.href}`); if (/mapped\.css/.test(sheet.href)) { is( sheet.sourceMapURL, "mapped.css.map", "X-SourceMap header took effect" ); seenSheets |= 1; } else if (/mapped2\.css/.test(sheet.href)) { is( sheet.sourceMapURL, "mapped2.css.map", "SourceMap header took effect" ); seenSheets |= 2; } else { ok(false, "sheet does not have source map URL"); } } is(seenSheets, 3, "seen all source-mapped sheets"); }); } ); });