mozilla-central/toolkit/components/extensions/test/xpcshell/test_ext_background_iframe.js (file symbol)

Source code

Revision control

Copy as Markdown

Other Tools

Test Info: Warnings

"use strict";
const { Management } = ChromeUtils.importESModule(
);
const server = AddonTestUtils.createHttpServer({
hosts: ["example.com"],
});
// One test below relies on a slow-loading stylesheet. This function and promise
// enables the script to control exactly when the stylesheet load should finish.
let allowStylesheetToLoad;
let stylesheetBlockerPromise = new Promise(resolve => {
allowStylesheetToLoad = resolve;
});
server.registerPathHandler("/slow.css", (request, response) => {
response.setHeader("Cache-Control", "no-cache", false);
response.setHeader("Content-Type", "text/css", false);
response.processAsync();
stylesheetBlockerPromise.then(() => {
response.write("body { color: rgb(1, 2, 3); }");
response.finish();
});
});
// Test helper to keep track of the number of background context loads, from
// any extension.
class BackgroundWatcher {
constructor() {
// Number of background page loads observed.
this.bgBrowserCount = 0;
// Number of top-level background context loads observed.
this.bgViewCount = 0;
this.observing = false;
this.onBrowserInserted = this.onBrowserInserted.bind(this);
this.onBackgroundViewLoaded = this.onBackgroundViewLoaded.bind(this);
this.startObserving();
}
startObserving() {
this.observing = true;
Management.on("extension-browser-inserted", this.onBrowserInserted);
}
stopObserving() {
this.observing = false;
Management.off("extension-browser-inserted", this.onBrowserInserted);
// Note: onBrowserInserted adds message listeners to the message manager
// of background contexts, but we do not explicitly unregister these here
// because the caller should only stop observing after knowing for sure
// that there are no new or pending loads of background pages.
}
onBrowserInserted(eventName, browser) {
Assert.equal(eventName, "extension-browser-inserted", "Seen bg browser");
if (!browser.getAttribute("webextension-view-type") === "background") {
return;
}
this.bgBrowserCount++;
browser.messageManager.addMessageListener(
"Extension:BackgroundViewLoaded",
this.onBackgroundViewLoaded
);
}
onBackgroundViewLoaded({ data }) {
if (!this.observing) {
// We shouldn't receive this event - see comment in stopObserving.
Assert.ok(false, "Got onBackgroundViewLoaded while !observing");
}
this.bgViewCount++;
Assert.ok(data.childId, "childId passed to Extension:BackgroundViewLoaded");
}
}
add_task(async function test_first_extension_api_call_in_iframe() {
// In this test we test what happens when an extension API call happens in
// an iframe before the top-level document observes DOMContentLoaded.
//
// 1. Because DOMContentLoaded is blocked on the execution on <script defer>,
// and <script defer> is blocked on stylesheet load completion, we embed
// both elements in the top-level document to postpone DOMContentLoaded.
// 2. We load an iframe with a moz-extension document and call an extension
// API in the context of that frame at iframe.onload.
// Because there is no <script> in the iframe, iframe.onload dispatches
// before DOMContentLoaded of the top-level document.
// 3. We add several sanity checks to verify that the order of execution is
// as expected.
//
function backgroundScript() {
// Note: no extension API calls until window.onload to avoid side effects.
// Saving any relevant state in global variables to assert later.
const readyStateAtTopLevelScriptExecution = document.readyState;
globalThis.readyStateAtFrameLoad = "(to be set in iframe.onload)";
globalThis.readyStateInScriptDefer = "(to be set in deferred script)";
globalThis.styleSheetStateAtFrameLoad = "(to be set in iframe.onload)";
globalThis.styleSheetStateInScriptDefer = "(to be set in deferred script)";
globalThis.bodyAtFrameLoad = "(to be set in iframe.onload)";
globalThis.scriptRunInFrame = "(to be set in iframe.onload)";
globalThis.scriptDeferRunAfterFrameLoad = "(to be set in deferred script)";
// We use a slow-loading stylesheet to block `<script defer>` execution,
// which in turn postpones DOMContentLoaded. This method checks whether
// the stylesheet has been loaded.
globalThis.getStyleSheetState = () => {
if (getComputedStyle(document.body).color === "rgb(1, 2, 3)") {
return "slow.css loaded";
}
return "slow.css not loaded";
};
const handle_iframe_onload = event => {
const iframe = event.target;
// Note: using dump instead of browser.test.log because we want to avoid
// extension API calls until we've completed the extension API call in
// the iframe below.
dump(`iframe.onload triggered\n`);
globalThis.styleSheetStateAtFrameLoad = globalThis.getStyleSheetState();
globalThis.readyStateAtFrameLoad = document.readyState;
globalThis.bodyAtFrameLoad = iframe.contentDocument.body.textContent;
// Now, call the extension API in the context of the iframe. We cannot
// use <script> inside the iframe, because its execution is also
// postponed by the slow style trick that we use to postpone
// DOMContentLoaded.
// The exact API call does not matter, as any extension API call will
// ensure that ProxyContextParent is initialized if it was not before:
iframe.contentWindow.browser.runtime.getPlatformInfo().then(info => {
dump(`Extension API call made a roundtrip through the parent\n`);
globalThis.scriptRunInFrame = true;
// By now, we have run an extension API call in the iframe, so we
// don't need to be careful with avoiding extension API calls in the
// top-level context. Thus we can now use browser.test APIs here.
browser.test.assertTrue("os" in info, "extension API called in iframe");
browser.test.assertTrue(
iframe.contentWindow.browser.extension.getBackgroundPage() === window,
"extension.getBackgroundPage() returns the top context"
);
// Allow stylesheet load to complete, which unblocks DOMContentLoaded
// and window.onload.
browser.test.sendMessage("allowStylesheetToLoad");
});
};
// background.js runs before <iframe> is inserted. This capturing listener
// should detect iframe.onload once it fires, through event bubbling.
document.addEventListener(
"load",
function listener(event) {
if (event.target.id === "iframe") {
document.removeEventListener("load", listener, true);
handle_iframe_onload(event);
}
},
true
);
window.onload = () => {
// First, several sanity checks to verify that the timing of script
// execution in the iframe vs DOMContentLoaded is as expected.
browser.test.assertEq(
"loading",
readyStateAtTopLevelScriptExecution,
"Top-level script should run immediately while DOM is still loading"
);
function assertBeforeDOMContentLoaded(actualReadyState, message) {
browser.test.assertTrue(
actualReadyState === "interactive" || actualReadyState === "loading",
`${message}, actual readyState=${actualReadyState}`
);
}
assertBeforeDOMContentLoaded(
globalThis.readyStateAtFrameLoad,
"frame.onload + script should run before DOMContentLoaded fires"
);
assertBeforeDOMContentLoaded(
globalThis.readyStateInScriptDefer,
"<script defer> should run right before DOMContentLoaded fires"
);
browser.test.assertEq(
"complete",
document.readyState,
"Sanity check: DOMContentLoaded has triggerd before window.onload"
);
// Sanity check: Verify that the stylesheet was still loading while
// frame.onload was executing. This should be true because the style
// sheet loads very slowly.
browser.test.assertEq(
"slow.css not loaded",
globalThis.styleSheetStateAtFrameLoad,
"Sanity check: stylesheet load pending during frame.onload"
);
browser.test.assertEq(
"slow.css loaded",
globalThis.styleSheetStateInScriptDefer,
"Sanity check: stylesheet loaded before deferred script"
);
// Sanity check: The deferred script should execute after iframe.onload,
// because `<script defer>` execution is blocked on stylesheet load
// completion, and we have a slow-loading stylesheet.
browser.test.assertEq(
globalThis.scriptDeferRunAfterFrameLoad,
true,
"Sanity check: iframe.onload should run before <script defer>"
);
// Sanity check: Verify that the moz-extension:-document was loaded in
// the frame at iframe.onload.
browser.test.assertEq(
"body_of_iframe",
globalThis.bodyAtFrameLoad,
"Sanity check: iframe.onload runs when document in frame was ready"
);
browser.test.sendMessage("top_and_frame_done");
};
dump(`background.js ran. Waiting for iframe.onload to continue.\n`);
}
function backgroundScriptDeferred() {
globalThis.scriptDeferRunAfterFrameLoad = globalThis.scriptRunInFrame;
globalThis.styleSheetStateInScriptDefer = globalThis.getStyleSheetState();
globalThis.readyStateInScriptDefer = document.readyState;
dump(`background-deferred.js ran. Expecting window.onload to run next.\n`);
}
const extension = ExtensionTestUtils.loadExtension({
manifest: {
background: {
page: "background.html",
},
},
files: {
"background.html": `<!DOCTYPE html>
<meta charset="utf-8">
<!-- background.js first, to never miss the iframe.onload event -->
<script src="background.js"></script>
<!-- iframe should start loading before slow.css blocks the DOM -->
<iframe src="background-subframe.html" id="iframe"></iframe>
<!--
Load a slow stylesheet AND add <script defer> to intentionally postpone
the DOMContentLoaded notification until well after background-top.js
has run and extension API calls have been processed, if any.
-->
<link rel="stylesheet" href="http://example.com/slow.css">
<script src="background-deferred.js" defer></script>
`,
"background-subframe.html": `<!DOCTYPE html>
<meta charset="utf-8">
<!-- No <script> here because their presence blocks iframe.onload -->
<body>body_of_iframe</body>`,
"background.js": backgroundScript,
"background-deferred.js": backgroundScriptDeferred,
},
});
const bgWatcher = new BackgroundWatcher();
// No "await extension.startup();" because extension.startup() in tests is
// currently blocked on background startup (due to TEST_NO_DELAYED_STARTUP
// defaulting to true). Because the background startup completion is blocked
// on the DOMContentLoaded of the background, extension.startup() does not
// resolve until we've unblocked the DOMContentLoaded notification.
const startupPromise = extension.startup();
await extension.awaitMessage("allowStylesheetToLoad");
Assert.equal(bgWatcher.bgBrowserCount, 1, "Got background page");
Assert.equal(bgWatcher.bgViewCount, 0, "Background view still loading");
info("frame loaded; allowing slow.css to load to unblock DOMContentLoaded");
allowStylesheetToLoad();
info("Waiting for extension.startup() to resolve (background completion)");
await startupPromise;
info("extension.startup() resolved. Waiting for top_and_frame_done...");
await extension.awaitMessage("top_and_frame_done");
Assert.equal(
extension.extension.backgroundContext?.uri?.spec,
`moz-extension://${extension.uuid}/background.html`,
`extension.backgroundContext should exist and point to the main background`
);
Assert.equal(bgWatcher.bgViewCount, 1, "Background has loaded once");
Assert.equal(
extension.extension.views.size,
2,
"Got ProxyContextParent instances for background and iframe"
);
await extension.unload();
bgWatcher.stopObserving();
});
add_task(async function test_only_script_execution_in_iframe() {
function backgroundSubframeScript() {
// The exact API call does not matter, as any extension API call will
// ensure that ProxyContextParent is initialized if it was not before:
browser.runtime.getPlatformInfo().then(info => {
browser.test.assertTrue("os" in info, "extension API called in iframe");
browser.test.assertTrue(
browser.extension.getBackgroundPage() === top,
"extension.getBackgroundPage() returns the top context"
);
browser.test.sendMessage("iframe_done");
});
}
const extension = ExtensionTestUtils.loadExtension({
manifest: {
background: {
page: "background.html",
},
},
files: {
"background.html": `<!DOCTYPE html>
<meta charset="utf-8">
<iframe src="background-subframe.html"></iframe>
`,
"background-subframe.html": `<!DOCTYPE html>
<meta charset="utf-8">
<script src="background-subframe.js"></script>
`,
"background-subframe.js": backgroundSubframeScript,
},
});
const bgWatcher = new BackgroundWatcher();
await extension.startup();
await extension.awaitMessage("iframe_done");
Assert.equal(bgWatcher.bgBrowserCount, 1, "Got background page");
Assert.equal(bgWatcher.bgViewCount, 1, "Got background view");
Assert.equal(
extension.extension.views.size,
2,
"Got ProxyContextParent instances for background and iframe"
);
Assert.equal(
extension.extension.backgroundContext?.uri?.spec,
`moz-extension://${extension.uuid}/background.html`,
`extension.backgroundContext should exist and point to the main background`
);
await extension.unload();
bgWatcher.stopObserving();
});