Bug 1559216 - Let tabs API wait until tab has been restored r=zombie

Differential Revision: https://phabricator.services.mozilla.com/D37323

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

browser/components/extensions/parent/ext-tabs.js

@@ -100,6 +100,9 @@ function showHiddenTabs(id) {
 
 let tabListener = {
   tabReadyInitialized: false,
+  // Map[tab -> Promise]
+  tabBlockedPromises: new WeakMap(),
+  // Map[tab -> Deferred]
   tabReadyPromises: new WeakMap(),
   initializingTabs: new WeakSet(),
 
@@ -128,6 +131,17 @@ let tabListener = {
     }
   },
 
+  blockTabUntilRestored(nativeTab) {
+    let promise = ExtensionUtils.promiseEvent(nativeTab, "SSTabRestored").then(
+      ({ target }) => {
+        this.tabBlockedPromises.delete(target);
+        return target;
+      }
+    );
+
+    this.tabBlockedPromises.set(nativeTab, promise);
+  },
+
   /**
    * Returns a promise that resolves when the tab is ready.
    * Tabs created via the `tabs.create` method are "ready" once the location
@@ -140,6 +154,10 @@ let tabListener = {
   awaitTabReady(nativeTab) {
     let deferred = this.tabReadyPromises.get(nativeTab);
     if (!deferred) {
+      let promise = this.tabBlockedPromises.get(nativeTab);
+      if (promise) {
+        return promise;
+      }
       deferred = PromiseUtils.defer();
       if (
         !this.initializingTabs.has(nativeTab) &&
@@ -1081,6 +1099,8 @@ this.tabs = class extends ExtensionAPI {
           let gBrowser = nativeTab.ownerGlobal.gBrowser;
           let newTab = gBrowser.duplicateTab(nativeTab);
 
+          tabListener.blockTabUntilRestored(newTab);
+
           return new Promise(resolve => {
             // We need to use SSTabRestoring because any attributes set before
             // are ignored. SSTabRestored is too late and results in a jump in

browser/components/extensions/test/browser/browser_ext_tabs_duplicate.js

@@ -182,7 +182,8 @@ add_task(async function testDuplicateResolvePromiseRightAway() {
 
   let extension = ExtensionTestUtils.loadExtension({
     manifest: {
-      permissions: ["tabs"],
+      // The host permission matches the above URL. No :8888 due to bug 1468162.
+      permissions: ["tabs", "http://mochi.test/"],
     },
 
     background: async function() {
@@ -208,6 +209,12 @@ add_task(async function testDuplicateResolvePromiseRightAway() {
               resolvedRightAway = true;
             }
 
+            // Regression test for bug 1559216: APIs such as tabs.executeScript
+            // should be queued until tabs.duplicate has restored the tab.
+            let code = "document.URL";
+            let [result] = await browser.tabs.executeScript(tab.id, { code });
+            browser.test.assertEq(tab.url, result, "executeScript result");
+
             await browser.tabs.remove([tabs[1].id, tab.id]);
             if (resolvedRightAway) {
               browser.test.notifyPass("tabs.duplicate.resolvePromiseRightAway");