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/* Any copyright is dedicated to the Public Domain.
* http://creativecommons.org/publicdomain/zero/1.0/ */
/**
* Document the basics of DevTools backend via Fronts in a test.
*/
"use strict";
const TEST_URL = "data:text/html,new-tab";
add_task(async () => {
// Allow logging all RDP packets
await pushPref("devtools.debugger.log", true);
// Really all of them
await pushPref("devtools.debugger.log.verbose", true);
// Instantiate a DevTools server
DevToolsServer.init();
DevToolsServer.registerAllActors();
// Instantiate a client connected to this server
const transport = DevToolsServer.connectPipe();
const client = new DevToolsClient(transport);
// This will trigger some handshake with the server
await client.connect();
// You need to call listTabs once to retrieve the existing list of Tab Descriptor actors...
const tabs = await client.mainRoot.listTabs();
// ... which will let you receive the 'tabListChanged' event.
// This is an empty RDP packet, you need to re-call listTabs to get the full new updated list of actors.
const onTabListUpdated = client.mainRoot.once("tabListChanged");
// Open a new tab.
await BrowserTestUtils.openNewForegroundTab({
gBrowser,
url: TEST_URL,
});
await onTabListUpdated;
// The new list of Tab descriptors should contain the newly opened tab
const newTabs = await client.mainRoot.listTabs();
is(newTabs.length, tabs.length + 1);
const tabDescriptorActor = newTabs.pop();
is(tabDescriptorActor.url, TEST_URL);
// Query the Tab Descriptor actor to retrieve its related Watcher actor.
// Each Descriptor actor has a dedicated watcher which will be scoped to the context of the descriptor.
// Here the watcher will focus on the related tab.
const watcherActor = await tabDescriptorActor.getWatcher();
// The call to Watcher Actor's watchTargets will emit target-available-form RDP events.
// One per available target. It will emit one for each immediatly available target,
// but also for any available later. That, until you call unwatchTarget method.
//
// Here I'm listening to "target-available" to get a Front instance, which helps call RDP methods.
// But this isn't an RDP event. This is a frontend-only thing.
const onTopTargetAvailable = watcherActor.once("target-available");
// watchTargets accepts "frame", "process" and "worker"
// When debugging a web page you want to listen to frame and worker targets.
// "frame" would better be named "WindowGlobal" as it will notify you about all the WindowGlobal of the page.
// Each top level documents and any iframe documents will have a related WindowGlobal,
// if any of these documents navigate, a new WindowGlobal will be instantiated.
// If you care about workers, listen to worker targets as well.
await watcherActor.watchTargets("frame");
// This is a trivial example so we have a unique WindowGlobal target for the top level document
const topTarget = await onTopTargetAvailable;
is(topTarget.url, TEST_URL);
// Similarly to watchTarget, the next call to watchResources will emit new resources right away as well as later.
const onConsoleMessages = topTarget.once("resource-available-form");
// If you want to observe anything, you have to use Watcher Actor's watchrResources API.
// The list of all available resources is here:
// https://searchfox.org/mozilla-central/source/devtools/server/actors/resources/index.js#9
// And you might have a look at each ResourceWatcher subclass to learn more about the fields exposed by each resource type:
// https://searchfox.org/mozilla-central/source/devtools/server/actors/resources
await watcherActor.watchResources(["console-message"]);
// You may use many useful actors on each target actor, like console, thread, ...
// You can get the full list of available actors in:
// https://searchfox.org/mozilla-central/source/devtools/server/actors/utils/actor-registry.js#176
// And then look into the mentioned path for implementation.
const webConsoleActor = await topTarget.getFront("console");
// Call the Console API in order to force emitting a console-message resource
await webConsoleActor.evaluateJSAsync({ text: "console.log('42')" });
// Wait for the related console-message resource
const resources = await onConsoleMessages;
// Note that resource-available-form comes with a "resources" attribute which is an array of resources
// which may contain various resource types.
is(resources[0].message.arguments[0], "42");
await client.close();
});
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