Bug 1636490 - rely on garbage collection rather than disabling via UI when testing accessibility panel. r=mtigley

Differential Revision: https://phabricator.services.mozilla.com/D74411

devtools/client/accessibility/test/browser/browser_accessibility_fission_switch_target.js

@@ -56,5 +56,5 @@ add_task(async () => {
   await navigateTo(CONTENT_PROCESS_URL);
   await runA11yPanelTests(CONTENT_PROCESS_EXPECTED, env);
 
-  await disableAccessibilityInspector(env);
+  await closeTabToolboxAccessibility(env.tab);
 });

devtools/client/accessibility/test/browser/browser_accessibility_panel_highlighter.js

@@ -6,6 +6,7 @@
 const TEST_URI = '<h1 id="h1">header</h1><p id="p">paragraph</p>';
 
 add_task(async function tabNotHighlighted() {
+  Services.prefs.setBoolPref("devtools.accessibility.auto-init.enabled", false);
   await addTab(buildURL(TEST_URI));
   const { toolbox } = await openInspector();
   const isHighlighted = await toolbox.isToolHighlighted("accessibility");
@@ -17,9 +18,11 @@ add_task(async function tabNotHighlighted() {
   );
 
   gBrowser.removeCurrentTab();
+  Services.prefs.clearUserPref("devtools.accessibility.auto-init.enabled");
 });
 
 add_task(async function tabHighlighted() {
+  Services.prefs.setBoolPref("devtools.accessibility.auto-init.enabled", false);
   let a11yService = await initA11y();
   ok(a11yService, "Accessibility service was started");
   await addTab(buildURL(TEST_URI));
@@ -28,4 +31,5 @@ add_task(async function tabHighlighted() {
 
   a11yService = null;
   gBrowser.removeCurrentTab();
+  Services.prefs.clearUserPref("devtools.accessibility.auto-init.enabled");
 });

devtools/client/accessibility/test/browser/browser_accessibility_panel_highlighter_multi_tab.js

@@ -6,6 +6,8 @@
 const TEST_URI = '<h1 id="h1">header</h1><p id="p">paragraph</p>';
 
 add_task(async function() {
+  Services.prefs.setBoolPref("devtools.accessibility.auto-init.enabled", false);
+
   const { toolbox: toolbox1 } = await addTestTab(buildURL(TEST_URI));
   const { toolbox: toolbox2 } = await addTestTab(buildURL(TEST_URI));
   const options = await openOptions(toolbox2);
@@ -33,15 +35,23 @@ add_task(async function() {
   await toggleAccessibility(options);
   await toggleAccessibility(options);
 
-  const panel = await toolbox2.selectTool("accessibility");
-  await disableAccessibilityInspector({
-    panel,
-    win: panel.panelWin,
-    doc: panel.panelWin.document,
-  });
+  const { accessibilityProxy, panelWin } = await toolbox2.selectTool(
+    "accessibility"
+  );
+  // Disable accessibility service through the panel and wait for the shutdown
+  // event.
+  const shutdown = accessibilityProxy.accessibilityFront.once("shutdown");
+  const disableButton = await BrowserTestUtils.waitForCondition(
+    () => panelWin.document.getElementById("accessibility-disable-button"),
+    "Wait for the disable button."
+  );
+  EventUtils.sendMouseEvent({ type: "click" }, disableButton, panelWin);
+  await shutdown;
 
   await checkHighlighted(toolbox1, false);
   await checkHighlighted(toolbox2, false);
+
+  Services.prefs.clearUserPref("devtools.accessibility.auto-init.enabled");
 });
 
 async function openOptions(toolbox) {

devtools/client/accessibility/test/browser/head.js

@@ -37,8 +37,6 @@ const {
 
 // Enable the Accessibility panel
 Services.prefs.setBoolPref("devtools.accessibility.enabled", true);
-// Disable auto-init
-Services.prefs.setBoolPref("devtools.accessibility.auto-init.enabled", false);
 
 const SIMULATION_MENU_BUTTON_ID = "#simulation-menu-button";
 const TREE_FILTERS_MENU_ID = "accessibility-tree-filters-menu";
@@ -79,20 +77,21 @@ async function initA11y() {
  * Wait for accessibility service to shut down. We consider it shut down when
  * an "a11y-init-or-shutdown" event is received with a value of "0".
  */
-function shutdownA11y() {
-  if (!Services.appinfo.accessibilityEnabled) {
-    return Promise.resolve();
-  }
-
-  // Force collections to speed up accessibility service shutdown.
-  Cu.forceGC();
-  Cu.forceCC();
-  Cu.forceShrinkingGC();
-
+function waitForAccessibilityShutdown() {
   return new Promise(resolve => {
+    if (!Services.appinfo.accessibilityEnabled) {
+      resolve();
+      return;
+    }
+
     const observe = (subject, topic, data) => {
       if (data === "0") {
         Services.obs.removeObserver(observe, "a11y-init-or-shutdown");
+        // Sanity check
+        ok(
+          !Services.appinfo.accessibilityEnabled,
+          "Accessibility disabled in this process"
+        );
         resolve();
       }
     };
@@ -101,12 +100,24 @@ function shutdownA11y() {
     // accessibility service naturally if there are no more XPCOM references to
     // a11y related objects (after GC/CC).
     Services.obs.addObserver(observe, "a11y-init-or-shutdown");
+
+    // Force garbage collection.
+    SpecialPowers.gc();
+    SpecialPowers.forceShrinkingGC();
+    SpecialPowers.forceCC();
   });
 }
 
+/**
+ * Ensure that accessibility is completely shutdown.
+ */
+async function shutdownAccessibility(browser) {
+  await waitForAccessibilityShutdown();
+  await SpecialPowers.spawn(browser, [], waitForAccessibilityShutdown);
+}
+
 registerCleanupFunction(async () => {
   info("Cleaning up...");
-  await shutdownA11y();
   Services.prefs.clearUserPref("devtools.accessibility.auto-init.enabled");
   Services.prefs.clearUserPref("devtools.accessibility.enabled");
 });
@@ -154,23 +165,6 @@ async function addTestTab(url) {
   };
 }
 
-/**
- * Turn off accessibility features from within the panel. We call it before the
- * cleanup function to make sure that the panel is still present.
- */
-async function disableAccessibilityInspector(env) {
-  const { doc, win, panel } = env;
-  // Disable accessibility service through the panel and wait for the shutdown
-  // event.
-  const shutdown = panel.accessibilityProxy.accessibilityFront.once("shutdown");
-  const disableButton = await BrowserTestUtils.waitForCondition(
-    () => doc.getElementById("accessibility-disable-button"),
-    "Wait for the disable button."
-  );
-  EventUtils.sendMouseEvent({ type: "click" }, disableButton, win);
-  await shutdown;
-}
-
 /**
  * Open the Accessibility panel for the given tab.
  *
@@ -805,6 +799,27 @@ function addA11yPanelTestsTask(tests, uri, msg, options) {
   addA11YPanelTask(msg, uri, env => runA11yPanelTests(tests, env), options);
 }
 
+/**
+ * Borrowed from framework's shared head. Close toolbox, completely disable
+ * accessibility and remove the tab.
+ * @param  {Tab}
+ *         tab The tab to close.
+ * @return {Promise}
+ *         Resolves when the toolbox and tab have been destroyed and closed.
+ */
+async function closeTabToolboxAccessibility(tab = gBrowser.selectedTab) {
+  if (TargetFactory.isKnownTab(tab)) {
+    const target = await TargetFactory.forTab(tab);
+    if (target) {
+      await gDevTools.closeToolbox(target);
+    }
+  }
+
+  await shutdownAccessibility(gBrowser.getBrowserForTab(tab));
+  await removeTab(tab);
+  await new Promise(resolve => setTimeout(resolve, 0));
+}
+
 /**
  * A wrapper function around add_task that sets up the test environment, runs
  * the test and then disables accessibility tools.
@@ -818,7 +833,7 @@ function addA11YPanelTask(msg, uri, task, options = {}) {
     info(msg);
     const env = await addTestTab(buildURL(uri, options));
     await task(env);
-    await disableAccessibilityInspector(env);
+    await closeTabToolboxAccessibility(env.tab);
   });
 }