Bug 1536794 - Add test to cover /json/version endpoint and Target domain. r=ato

Depends on D24221

Differential Revision: https://phabricator.services.mozilla.com/D24222

--HG--
extra : moz-landing-system : lando

remote/RemoteAgent.js

@@ -94,12 +94,15 @@ class ParentRemoteAgent {
   async close() {
     if (this.listening) {
       try {
+        // Disconnect the targets first in order to ensure closing all pending
+        // connection first. Otherwise Httpd's stop is not going to resolve.
+        this.targets.clear();
+
         await this.server.stop();
 
         Preferences.reset(Object.keys(RecommendedPreferences));
 
         this.tabs.stop();
-        this.targets.clear();
       } catch (e) {
         throw new Error(`Unable to stop agent: ${e.message}`, e);
       }

remote/test/browser/browser.ini

@@ -7,3 +7,4 @@ support-files =
 
 [browser_cdp.js]
 [browser_tabs.js]
+[browser_target.js]

remote/test/browser/browser_target.js

@@ -0,0 +1,70 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+/* global getCDP */
+
+// Test the Target domain
+
+add_task(async function() {
+  try {
+    await testCDP();
+  } catch (e) {
+    // Display better error message with the server side stacktrace
+    // if an error happened on the server side:
+    if (e.response) {
+      throw new Error("CDP Exception:\n" + e.response + "\n");
+    } else {
+      throw e;
+    }
+  }
+});
+
+async function testCDP() {
+  // Start the CDP server
+  const RemoteAgent = Cc["@mozilla.org/remote/agent"].getService(Ci.nsISupports).wrappedJSObject;
+  RemoteAgent.tabs.start();
+  RemoteAgent.listen(Services.io.newURI("http://localhost:9222"));
+
+  // Retrieve the chrome-remote-interface library object
+  const CDP = await getCDP();
+
+  // Connect to the server
+  const {webSocketDebuggerUrl} = await CDP.Version();
+  is(webSocketDebuggerUrl, "ws://localhost:9222/devtools/browser", "Version endpoint refers to /devtools/browser target");
+
+  const client = await CDP({"target": webSocketDebuggerUrl});
+  ok(true, "CDP client has been instantiated");
+
+  const {Target} = client;
+  ok("Target" in client, "Target domain is available");
+
+  // Instruct the server to fire Target.targetCreated events
+  Target.setDiscoverTargets({ discover: true });
+
+  // Create a new target so that the test runs against a fresh new tab
+  const targetCreated = Target.targetCreated();
+  const {targetId} = await Target.createTarget();
+  ok(true, "Target created");
+  ok(!!targetId, "createTarget returns a non-empty target id");
+  const {targetInfo} = await targetCreated;
+  is(targetId, targetInfo.targetId, "createTarget and targetCreated refers to the same target id");
+  is(targetInfo.type, "page", "The target is a page");
+
+  const attachedToTarget = Target.attachedToTarget();
+  const {sessionId} = await Target.attachToTarget({ targetId });
+  ok(true, "Target attached");
+
+  const attachedEvent = await attachedToTarget;
+  ok(true, "Received Target.attachToTarget event");
+  is(attachedEvent.sessionId, sessionId, "attachedToTarget and attachToTarget returns the same session id");
+  is(attachedEvent.targetInfo.type, "page", "attachedToTarget creates a tab by default");
+
+  await client.close();
+  ok(true, "The client is closed");
+
+  BrowserTestUtils.removeTab(gBrowser.selectedTab);
+
+  await RemoteAgent.close();
+}