Bug 1625500 - fix use of .then(x, x) in the tree, r=marionette-reviewers,Standard8,whimboo

Differential Revision: https://phabricator.services.mozilla.com/D68614

browser/components/preferences/in-content/tests/browser_extension_controlled.js

@@ -1124,8 +1124,8 @@ add_task(async function testExtensionControlledProxyConfig() {
   async function closeProxyPanel(panelObj) {
     let dialog = panelObj.panel.document.getElementById("ConnectionsDialog");
     dialog.cancelDialog();
-    let panelClosingEvent = await panelObj.closingPromise;
-    ok(panelClosingEvent, "Proxy panel closed.");
+    await panelObj.closingPromise;
+    is(panelObj.pane.state, "closed", "Proxy panel closed.");
   }
 
   await openPreferencesViaOpenPreferencesAPI("paneGeneral", {

browser/components/preferences/in-content/tests/head.js

@@ -130,13 +130,12 @@ function waitForEvent(aSubject, aEventName, aTimeoutMs, aTarget) {
     eventDeferred.resolve(aEvent);
   };
 
-  function cleanup(aEventOrError) {
+  function cleanup() {
     // unhook listener in case of success or failure
     aSubject.removeEventListener(aEventName, listener);
-    return aEventOrError;
   }
   aSubject.addEventListener(aEventName, listener);
-  return eventDeferred.promise.then(cleanup, cleanup);
+  return eventDeferred.promise.finally(cleanup);
 }
 
 function openPreferencesViaOpenPreferencesAPI(aPane, aOptions) {

browser/components/sessionstore/SessionStore.jsm

@@ -2235,7 +2235,7 @@ var SessionStoreInternal = {
                 deferred.resolve();
               }
             }, topic);
-            deferred.promise.then(cleanup, cleanup);
+            deferred.promise.finally(cleanup);
             return deferred;
           };
 
@@ -6158,10 +6158,7 @@ var SessionStoreInternal = {
     );
     // Ensure that the timer is both canceled once we are done with it
     // and not garbage-collected until then.
-    deferred.promise.then(
-      () => timer.cancel(),
-      () => timer.cancel()
-    );
+    deferred.promise.finally(() => timer.cancel());
     return deferred;
   },
 

browser/modules/FaviconLoader.jsm

@@ -151,7 +151,7 @@ class FaviconLoad {
       this.dataBuffer = null;
       this.stream = null;
     };
-    this._deferred.promise.then(cleanup, cleanup);
+    this._deferred.promise.finally(cleanup);
 
     this.dataBuffer = new StorageStream(STREAM_SEGMENT_SIZE, PR_UINT32_MAX);
 

devtools/client/inspector/markup/markup.js

@@ -750,7 +750,7 @@ MarkupView.prototype = {
     this._briefBoxModelPromise = new Promise(resolve => {
       _resolve = resolve;
       this._briefBoxModelTimer = setTimeout(() => {
-        this._hideBoxModel().then(resolve, resolve);
+        this._hideBoxModel().finally(resolve);
       }, NEW_SELECTION_HIGHLIGHTER_TIMER);
     });
     this._briefBoxModelPromise.resolve = _resolve;

devtools/client/inspector/rules/rules.js

@@ -1891,9 +1891,7 @@ RuleViewTool.prototype = {
 
     if (selectElement) {
       const done = this.inspector.updating("rule-view");
-      this.view
-        .selectElement(this.inspector.selection.nodeFront)
-        .then(done, done);
+      this.view.selectElement(this.inspector.selection.nodeFront).finally(done);
     }
   },
 

devtools/client/netmonitor/src/connector/chrome/bulk-loader.js

@@ -24,13 +24,13 @@ class Scheduler {
 
   dequeue() {
     const self = this;
-    const recursive = resolve => {
+    const recursive = () => {
       self.dequeue();
     };
     this.busy = true;
     const next = this.queue.shift();
     if (next) {
-      next().then(recursive, recursive);
+      next().finally(recursive);
     } else {
       this.busy = false;
     }

devtools/client/webconsole/actions/input.js

@@ -87,8 +87,6 @@ function evaluateExpression(expression, from = "input") {
 
     // Even if the evaluation fails,
     // we still need to pass the error response to onExpressionEvaluated.
-    const onSettled = res => res;
-
     const response = await client
       .evaluateJSAsync(expression, {
         frameActor: await webConsoleUI.getFrameActor(),
@@ -96,7 +94,7 @@ function evaluateExpression(expression, from = "input") {
         selectedTargetFront: toolbox && toolbox.getSelectedTargetFront(),
         mapped,
       })
-      .then(onSettled, onSettled);
+      .catch(e => e);
 
     return dispatch(onExpressionEvaluated(response));
   };

devtools/server/tests/xpcshell/test_forwardingprefix.js

@@ -115,7 +115,7 @@ function tryActors(reachables, completed) {
         executeSoon(completed, "tryActors callback " + completed.name);
       }
     };
-    promise.then(callback, callback);
+    promise.catch(e => e).then(callback);
   }
 }
 

devtools/shared/transport/stream-utils.js

@@ -96,7 +96,8 @@ function StreamCopier(input, output, length) {
   // fail scenarios, but also emit events (due to the EventEmitter) for other
   // states, like progress.
   this.then = this._deferred.then.bind(this._deferred);
-  this.then(this._destroy, this._destroy);
+  this.finally = this._deferred.finally.bind(this._deferred);
+  this.finally(this._destroy);
 
   // Stream ready callback starts as |_copy|, but may switch to |_flush| at end
   // if flushing would block the output stream.

dom/base/test/browser_use_counters.js

@@ -177,7 +177,7 @@ function grabHistogramsFromContent(use_counter_middlefix, page_before = null) {
   };
   return BrowserTestUtils.waitForCondition(() => {
     return page_before != gather()[0];
-  }).then(gather, gather);
+  }).finally(gather);
 }
 
 var check_use_counter_iframe = async function(

dom/cache/test/mochitest/test_cache_match_vary.js

@@ -511,14 +511,9 @@ function testMultipleCacheEntries() {
 
 // Make sure to clean up after each test step.
 function step(testPromise) {
-  return testPromise.then(
-    function() {
-      caches.delete(name);
-    },
-    function() {
-      caches.delete(name);
-    }
-  );
+  return testPromise.finally(function() {
+    caches.delete(name);
+  });
 }
 
 step(testBasics())

dom/canvas/test/imagebitmap_on_worker.js

@@ -153,6 +153,6 @@ onmessage = function(event) {
     doneTask();
   } else if (event.data.type == "testBug1239300") {
     var promise = testBug1239300();
-    promise.then(doneTask, doneTask);
+    promise.finally(doneTask);
   }
 };

dom/events/test/pointerevents/test_touch_action.html

@@ -92,7 +92,7 @@ if (isApzEnabled()) {
   SimpleTest.waitForExplicitFinish();
   window.onload = function() {
     runSubtestsSeriallyInFreshWindows(subtests)
-    .then(SimpleTest.finish, SimpleTest.finish);
+    .finally(SimpleTest.finish);
   };
 }
 

dom/media/PeerConnection.jsm

@@ -575,7 +575,7 @@ class RTCPeerConnection {
           this.updateNegotiationNeeded();
         }
       };
-      p.then(doNextOperation, doNextOperation);
+      p.finally(doNextOperation);
     });
     if (this._operations.length == 1) {
       this._operations[0]();

dom/media/test/can_play_type_ogg.js

@@ -68,5 +68,5 @@ function check_ogg(v, enabled, finish) {
     .then(verify_opus_support)
     .then(opus_enable)
     .then(opus_disable)
-    .then(unspported_ogg, unspported_ogg);
+    .finally(unspported_ogg);
 }

dom/push/test/xpcshell/test_service_child.js

@@ -41,7 +41,7 @@ if (isParent) {
     registerCleanupFunction(() => {
       return db.drop().then(_ => db.close());
     });
-    setUpServiceInParent(PushService, db).then(run_next_test, run_next_test);
+    setUpServiceInParent(PushService, db).finally(run_next_test);
   });
 }
 
@@ -352,6 +352,6 @@ add_test(function test_subscribe_missing_principal() {
 
 if (isParent) {
   add_test(function tearDown() {
-    tearDownServiceInParent(db).then(run_next_test, run_next_test);
+    tearDownServiceInParent(db).finally(run_next_test);
   });
 }

dom/serviceworkers/test/test_privateBrowsing.html

@@ -81,7 +81,7 @@ function cleanup() {
 
 function runTest() {
   if (!steps.length) {
-    registration.unregister().then(cleanup, cleanup);
+    registration.unregister().finally(cleanup);
 
     return;
   }

dom/serviceworkers/test/test_service_worker_allowed.html

@@ -55,7 +55,7 @@
       Promise.all([
           testPermissiveHeader(),
           testPreciseHeader(),
-      ]).then(SimpleTest.finish, SimpleTest.finish);
+      ]).finally(SimpleTest.finish);
     }, (x) => {
       ok(false, "Registration should not succeed, but it did");
       SimpleTest.finish();

dom/tests/mochitest/fetch/worker_wrapper.js

@@ -32,16 +32,15 @@ addEventListener("message", function workerWrapperOnMessage(e) {
   var data = e.data;
 
   function runTestAndReportToClient(event) {
-    var done = function(res) {
+    var done = function() {
       client.postMessage({ type: "finish", context });
-      return res;
     };
 
     try {
       // runTest() is provided by the test.
-      var result = runTest().then(done, done);
+      var promise = runTest().finally(done);
       if ("waitUntil" in event) {
-        event.waitUntil(result);
+        event.waitUntil(promise);
       }
     } catch (e) {
       client.postMessage({

dom/workers/test/browser_worker_use_counters.js

@@ -30,7 +30,7 @@ function grabHistogramsFromContent(
   };
   return BrowserTestUtils.waitForCondition(() => {
     return counter_before != gather()[0];
-  }).then(gather, gather);
+  }).finally(gather);
 }
 
 var check_use_counter_worker = async function(

gfx/layers/apz/test/mochitest/helper_fission_animation_styling_in_oopif.html

@@ -16,7 +16,7 @@ FissionTestHelper.startTestPromise
   .then(loadOOPIFrame("testframe", "helper_fission_empty.html"))
   .then(waitUntilApzStable)
   .then(runAsyncContinuation(test))
-  .then(FissionTestHelper.subtestDone, FissionTestHelper.subtestDone);
+  .finally(FissionTestHelper.subtestDone);
 
 async function setup_in_oopif() {
   const setup = function() {

gfx/layers/apz/test/mochitest/helper_fission_animation_styling_in_transformed_oopif.html

@@ -16,7 +16,7 @@ FissionTestHelper.startTestPromise
   .then(loadOOPIFrame("testframe", "helper_fission_empty.html"))
   .then(waitUntilApzStable)
   .then(runAsyncContinuation(test))
-  .then(FissionTestHelper.subtestDone, FissionTestHelper.subtestDone);
+  .finally(FissionTestHelper.subtestDone);
 
 async function setup_in_oopif() {
   const setup = function() {

gfx/layers/apz/test/mochitest/helper_fission_basic.html

@@ -16,7 +16,7 @@ FissionTestHelper.startTestPromise
   .then(loadOOPIFrame("testframe", "helper_fission_empty.html"))
   .then(waitUntilApzStable)
   .then(runAsyncContinuation(test))
-  .then(FissionTestHelper.subtestDone, FissionTestHelper.subtestDone);
+  .finally(FissionTestHelper.subtestDone);
 
 
 // The actual test

gfx/layers/apz/test/mochitest/helper_fission_event_region_override.html

@@ -17,7 +17,7 @@ FissionTestHelper.startTestPromise
   .then(loadOOPIFrame("testframe", "helper_fission_empty.html"))
   .then(waitUntilApzStable)
   .then(runAsyncContinuation(test))
-  .then(FissionTestHelper.subtestDone, FissionTestHelper.subtestDone);
+  .finally(FissionTestHelper.subtestDone);
 
 
 // The actual test

gfx/layers/apz/test/mochitest/helper_fission_scroll_oopif.html

@@ -17,7 +17,7 @@ FissionTestHelper.startTestPromise
   .then(loadOOPIFrame("testframe", "helper_fission_empty.html"))
   .then(waitUntilApzStable)
   .then(runAsyncContinuation(test))
-  .then(FissionTestHelper.subtestDone, FissionTestHelper.subtestDone);
+  .finally(FissionTestHelper.subtestDone);
 
 
 let code_for_oopif_to_run = function() {

gfx/layers/apz/test/mochitest/helper_fission_transforms.html

@@ -17,7 +17,7 @@ FissionTestHelper.startTestPromise
   .then(loadOOPIFrame("testframe", "helper_fission_empty.html"))
   .then(waitUntilApzStable)
   .then(runAsyncContinuation(test))
-  .then(FissionTestHelper.subtestDone, FissionTestHelper.subtestDone);
+  .finally(FissionTestHelper.subtestDone);
 
 
 let code_for_oopif_to_run = function() {

gfx/layers/apz/test/mochitest/test_bug1464568.html

@@ -20,7 +20,7 @@
       // inside an iframe which means we have no control over the root APZC.
       window.onload = () => {
         runSubtestsSeriallyInFreshWindows(subtests)
-        .then(SimpleTest.finish, SimpleTest.finish);
+        .finally(SimpleTest.finish);
       };
     }
   </script>

gfx/layers/apz/test/mochitest/test_group_checkerboarding.html

@@ -24,7 +24,7 @@
       // inside an iframe which means we have no control over the root APZC.
       window.onload = () => {
         runSubtestsSeriallyInFreshWindows(subtests)
-        .then(SimpleTest.finish, SimpleTest.finish);
+        .finally(SimpleTest.finish);
       };
     }
   </script>

gfx/layers/apz/test/mochitest/test_group_double_tap_zoom.html

@@ -25,7 +25,7 @@ if (isApzEnabled()) {
   SimpleTest.waitForExplicitFinish();
   window.onload = function() {
     runSubtestsSeriallyInFreshWindows(subtests)
-    .then(SimpleTest.finish, SimpleTest.finish);
+    .finally(SimpleTest.finish);
   };
 }
 

gfx/layers/apz/test/mochitest/test_group_fullscreen.html

@@ -23,7 +23,7 @@
       // inside an iframe which means we have no control over the root APZC.
       window.onload = () => {
         runSubtestsSeriallyInFreshWindows(subtests)
-        .then(SimpleTest.finish, SimpleTest.finish);
+        .finally(SimpleTest.finish);
       };
     }
   </script>

gfx/layers/apz/test/mochitest/test_group_hittest.html

@@ -47,7 +47,7 @@ if (isApzEnabled()) {
   SimpleTest.waitForExplicitFinish();
   window.onload = function() {
     runSubtestsSeriallyInFreshWindows(subtests)
-    .then(SimpleTest.finish, SimpleTest.finish);
+    .finally(SimpleTest.finish);
   };
 }
 

gfx/layers/apz/test/mochitest/test_group_keyboard.html

@@ -17,7 +17,7 @@ var subtests = [
       SimpleTest.waitForExplicitFinish();
       window.onload = function() {
         runSubtestsSeriallyInFreshWindows(subtests)
-        .then(SimpleTest.finish, SimpleTest.finish);
+        .finally(SimpleTest.finish);
       };
     } else {
       SimpleTest.ok(true, "Keyboard APZ is disabled");

gfx/layers/apz/test/mochitest/test_group_mainthread.html

@@ -17,7 +17,7 @@ if (isApzEnabled()) {
   SimpleTest.waitForExplicitFinish();
   window.onload = function() {
     runSubtestsSeriallyInFreshWindows(subtests)
-    .then(SimpleTest.finish, SimpleTest.finish);
+    .finally(SimpleTest.finish);
   };
 }
 

gfx/layers/apz/test/mochitest/test_group_minimum_scale_size.html

@@ -46,7 +46,7 @@ if (isApzEnabled()) {
   // inside an iframe which means we have no control over the root APZC.
   window.onload = () => {
     runSubtestsSeriallyInFreshWindows(subtests)
-    .then(SimpleTest.finish, SimpleTest.finish);
+    .finally(SimpleTest.finish);
   };
 }
 </script>

gfx/layers/apz/test/mochitest/test_group_mouseevents.html

@@ -47,7 +47,7 @@ if (isApzEnabled()) {
   SimpleTest.expectAssertions(0, 2); // from helper_bug1550510.html, bug 1232856
   window.onload = function() {
     runSubtestsSeriallyInFreshWindows(subtests)
-    .then(SimpleTest.finish, SimpleTest.finish);
+    .finally(SimpleTest.finish);
   };
 }
 

gfx/layers/apz/test/mochitest/test_group_overrides.html

@@ -26,7 +26,7 @@ if (isApzEnabled()) {
   SimpleTest.waitForExplicitFinish();
   window.onload = function() {
     runSubtestsSeriallyInFreshWindows(subtests)
-    .then(SimpleTest.finish, SimpleTest.finish);
+    .finally(SimpleTest.finish);
   };
 }
 

gfx/layers/apz/test/mochitest/test_group_pointerevents.html

@@ -29,7 +29,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=1285070
     SimpleTest.waitForExplicitFinish();
     window.onload = function() {
       runSubtestsSeriallyInFreshWindows(subtests)
-      .then(SimpleTest.finish, SimpleTest.finish);
+      .finally(SimpleTest.finish);
     };
   }
 

gfx/layers/apz/test/mochitest/test_group_scroll_snap.html

@@ -25,7 +25,7 @@ if (isApzEnabled()) {
   SimpleTest.waitForExplicitFinish();
   window.onload = function() {
     runSubtestsSeriallyInFreshWindows(subtests)
-    .then(SimpleTest.finish, SimpleTest.finish);
+    .finally(SimpleTest.finish);
   };
 }
 

gfx/layers/apz/test/mochitest/test_group_touchevents-2.html

@@ -56,7 +56,7 @@ if (isApzEnabled()) {
   SimpleTest.waitForExplicitFinish();
   window.onload = function() {
     runSubtestsSeriallyInFreshWindows(subtests)
-    .then(SimpleTest.finish, SimpleTest.finish);
+    .finally(SimpleTest.finish);
   };
 }
 

gfx/layers/apz/test/mochitest/test_group_touchevents-3.html

@@ -36,7 +36,7 @@ if (isApzEnabled()) {
   SimpleTest.waitForExplicitFinish();
   window.onload = function() {
     runSubtestsSeriallyInFreshWindows(subtests)
-    .then(SimpleTest.finish, SimpleTest.finish);
+    .finally(SimpleTest.finish);
   };
 }
 

gfx/layers/apz/test/mochitest/test_group_touchevents-4.html

@@ -34,7 +34,7 @@ if (isApzEnabled()) {
   SimpleTest.waitForExplicitFinish();
   window.onload = function() {
     runSubtestsSeriallyInFreshWindows(subtests)
-    .then(SimpleTest.finish, SimpleTest.finish);
+    .finally(SimpleTest.finish);
   };
 }
 

gfx/layers/apz/test/mochitest/test_group_touchevents.html

@@ -44,7 +44,7 @@ if (isApzEnabled()) {
   SimpleTest.waitForExplicitFinish();
   window.onload = function() {
     runSubtestsSeriallyInFreshWindows(subtests)
-    .then(SimpleTest.finish, SimpleTest.finish);
+    .finally(SimpleTest.finish);
   };
 }
 

gfx/layers/apz/test/mochitest/test_group_wheelevents.html

@@ -48,7 +48,7 @@ if (isApzEnabled()) {
   SimpleTest.waitForExplicitFinish();
   window.onload = function() {
     runSubtestsSeriallyInFreshWindows(subtests)
-    .then(SimpleTest.finish, SimpleTest.finish);
+    .finally(SimpleTest.finish);
   };
 }
 

gfx/layers/apz/test/mochitest/test_group_zoom-2.html

@@ -44,7 +44,7 @@ if (isApzEnabled()) {
   SimpleTest.waitForExplicitFinish();
   window.onload = function() {
     runSubtestsSeriallyInFreshWindows(subtests)
-    .then(SimpleTest.finish, SimpleTest.finish);
+    .finally(SimpleTest.finish);
   };
 }
 

gfx/layers/apz/test/mochitest/test_group_zoom.html

@@ -63,7 +63,7 @@ if (isApzEnabled()) {
   SimpleTest.waitForExplicitFinish();
   window.onload = function() {
     runSubtestsSeriallyInFreshWindows(subtests)
-    .then(SimpleTest.finish, SimpleTest.finish);
+    .finally(SimpleTest.finish);
   };
 }
 

gfx/layers/apz/test/mochitest/test_group_zoomToFocusedInput.html

@@ -16,7 +16,7 @@ if (isApzEnabled()) {
   SimpleTest.waitForExplicitFinish();
   window.onload = function() {
     runSubtestsSeriallyInFreshWindows(subtests)
-    .then(SimpleTest.finish, SimpleTest.finish);
+    .finally(SimpleTest.finish);
   };
 }
 

mobile/android/components/geckoview/GeckoViewPermission.js

@@ -88,7 +88,7 @@ GeckoViewPermission.prototype = {
     };
 
     if (dispatcher) {
-      this.getAppPermissions(dispatcher, perms).then(callback, callback);
+      this.getAppPermissions(dispatcher, perms).finally(callback);
     } else {
       // No dispatcher; just bail.
       callback();

testing/marionette/stream-utils.js

@@ -97,7 +97,8 @@ function StreamCopier(input, output, length) {
   // or fail scenarios, but also emit events (due to the EventEmitter)
   // for other states, like progress.
   this.then = this._deferred.promise.then.bind(this._deferred.promise);
-  this.then(this._destroy, this._destroy);
+  this.finally = this._deferred.promise.finally.bind(this._deferred.promise);
+  this.finally(this._destroy);
 
   // Stream ready callback starts as |_copy|, but may switch to |_flush|
   // at end if flushing would block the output stream.

testing/xpcshell/head.js

@@ -1639,7 +1639,7 @@ try {
 
     let complete = false;
     let doComplete = () => (complete = true);
-    _TelemetryController.testRegisterJsProbes().then(doComplete, doComplete);
+    _TelemetryController.testRegisterJsProbes().finally(doComplete);
     _Services.tm.spinEventLoopUntil(() => complete);
   }
 } catch (e) {

toolkit/components/asyncshutdown/AsyncShutdown.jsm

@@ -288,10 +288,7 @@ function looseTimer(delay) {
   );
   // Ensure that the timer is both canceled once we are done with it
   // and not garbage-collected until then.
-  deferred.promise.then(
-    () => timer.cancel(),
-    () => timer.cancel()
-  );
+  deferred.promise.finally(() => timer.cancel());
   return deferred;
 }
 

toolkit/components/downloads/DownloadCore.jsm

@@ -802,7 +802,7 @@ Download.prototype = {
     if (!this._promiseCanceled) {
       // Start a new cancellation request.
       this._promiseCanceled = new Promise(resolve => {
-        this._currentAttempt.then(resolve, resolve);
+        this._currentAttempt.finally(resolve);
       });
 
       // The download can already be restarted.

toolkit/components/extensions/ExtensionParent.jsm

@@ -1033,7 +1033,7 @@ ParentAPIManager = {
       let remove = () => {
         listenerPromises.delete(promise);
       };
-      promise.then(remove, remove);
+      promise.finally(remove);
     }
 
     let handler = await promise;

toolkit/components/extensions/test/xpcshell/test_ext_contexts.js

@@ -48,6 +48,8 @@ add_task(async function test_post_unload_promises() {
 
   context.wrapPromise(Promise.resolve("resolved")).then(fail);
 
+  // We care about which way we fail here (if we do), so we don't want to use finally.
+  // eslint-disable-next-line mozilla/use-finally
   context.wrapPromise(Promise.reject({ message: "rejected" })).then(fail, fail);
 
   context.unload();

toolkit/components/osfile/tests/xpcshell/test_osfile_async.js

@@ -9,5 +9,5 @@ const { OS } = ChromeUtils.import("resource://gre/modules/osfile.jsm");
 
 function run_test() {
   do_test_pending();
-  OS.File.getCurrentDirectory().then(do_test_finished, do_test_finished);
+  OS.File.getCurrentDirectory().finally(do_test_finished);
 }

toolkit/components/telemetry/app/ClientID.jsm

@@ -150,7 +150,7 @@ var ClientIDImpl = {
 
     this._loadClientIdTask = this._doLoadClientID();
     let clear = () => (this._loadClientIdTask = null);
-    this._loadClientIdTask.then(clear, clear);
+    this._loadClientIdTask.finally(clear);
     return this._loadClientIdTask;
   },
 
@@ -330,7 +330,7 @@ var ClientIDImpl = {
     // Asynchronous calls to getClientID will also be blocked on this.
     this._removeClientIdTask = this._doRemoveClientID();
     let clear = () => (this._removeClientIdTask = null);
-    this._removeClientIdTask.then(clear, clear);
+    this._removeClientIdTask.finally(clear);
 
     await this._removeClientIdTask;
 

toolkit/components/telemetry/app/TelemetrySend.jsm

@@ -469,7 +469,7 @@ var SendScheduler = {
     if (!this._sendTask) {
       this._sendTask = this._doSendTask();
       let clear = () => (this._sendTask = null);
-      this._sendTask.then(clear, clear);
+      this._sendTask.finally(clear);
     } else if (immediately) {
       CancellableTimeout.cancelTimeout();
     }
@@ -1521,7 +1521,7 @@ var TelemetrySendImpl = {
    */
   _trackPendingPingTask(promise) {
     let clear = () => this._pendingPingActivity.delete(promise);
-    promise.then(clear, clear);
+    promise.finally(clear);
     this._pendingPingActivity.add(promise);
   },
 

toolkit/components/telemetry/app/TelemetryStorage.jsm

@@ -856,7 +856,7 @@ var TelemetryStorageImpl = {
     // Make sure to clear |_cleanArchiveTask| once done.
     let clear = () => (this._cleanArchiveTask = null);
     // Since there's no archive cleaning task running, start it.
-    this._cleanArchiveTask = this._cleanArchive().then(clear, clear);
+    this._cleanArchiveTask = this._cleanArchive().finally(clear);
     return this._cleanArchiveTask;
   },
 
@@ -1541,7 +1541,7 @@ var TelemetryStorageImpl = {
    */
   _trackPendingPingSaveTask(promise) {
     let clear = () => this._activePendingPingSaves.delete(promise);
-    promise.then(clear, clear);
+    promise.finally(clear);
     this._activePendingPingSaves.add(promise);
   },
 

toolkit/components/thumbnails/BackgroundPageThumbs.jsm

@@ -602,8 +602,7 @@ Capture.prototype = {
       return;
     }
 
-    PageThumbs._store(this.url, data.finalURL, data.imageData, true).then(
-      done,
+    PageThumbs._store(this.url, data.finalURL, data.imageData, true).finally(
       done
     );
   },

toolkit/components/url-classifier/tests/mochitest/test_donottrack.html

@@ -127,7 +127,7 @@ let loop = function loop(index) {
     loop(index + 1);
   };
   let result = executeTest(test);
-  result.then(next, next);
+  result.finally(next);
 };
 
 SimpleTest.waitForExplicitFinish();

toolkit/modules/Sqlite.jsm

@@ -723,7 +723,7 @@ ConnectionData.prototype = Object.freeze({
   shrinkMemory() {
     this._log.info("Shrinking memory usage.");
     let onShrunk = this._clearIdleShrinkTimer.bind(this);
-    return this.execute("PRAGMA shrink_memory").then(onShrunk, onShrunk);
+    return this.execute("PRAGMA shrink_memory").finally(onShrunk);
   },
 
   discardCachedStatements() {

toolkit/modules/tests/xpcshell/test_Promise.js

@@ -31,7 +31,7 @@ var run_promise_tests = function run_promise_tests(tests, cb) {
       });
     };
     let result = test();
-    result.then(next, next);
+    result.finally(next);
   };
   return loop(0);
 };