Bug 1864896: Autofix unused function arguments (services). r=markh,sync-reviewers

Differential Revision: https://phabricator.services.mozilla.com/D202986
2024-11-26 22:32:46 +00:00 · 2024-03-02 15:26:03 +00:00 · 2024-03-02 15:26:03 +00:00 · 6e02473120
commit 6e02473120
parent 5a36ecfb41
75 changed files with 195 additions and 232 deletions
--- a/services/automation/ServicesAutomation.sys.mjs
+++ b/services/automation/ServicesAutomation.sys.mjs
@ -139,11 +139,11 @@ export var Authentication = {
    let mainWindow = Services.wm.getMostRecentWindow("navigator:browser");
    let newtab = mainWindow.gBrowser.addWebTab(uri);
    let win = mainWindow.gBrowser.getBrowserForTab(newtab);
-    win.addEventListener("load", function (e) {
+    win.addEventListener("load", function () {
      LOG("load");
    });

-    win.addEventListener("loadstart", function (e) {
+    win.addEventListener("loadstart", function () {
      LOG("loadstart");
    });

@ -299,7 +299,7 @@ export var Sync = {
    await this.wipeLogs();
  },

-  observe(subject, topic, data) {
+  observe(subject, topic) {
    LOG("Event received " + topic);
  },

--- a/services/common/async.sys.mjs
+++ b/services/common/async.sys.mjs
@ -289,7 +289,7 @@ class Watchdog {
    }
  }

-  observe(subject, topic, data) {
+  observe(subject, topic) {
    if (topic == "timer-callback") {
      this.abortReason = "timeout";
    } else if (topic == "quit-application") {
--- a/services/common/hawkrequest.sys.mjs
+++ b/services/common/hawkrequest.sys.mjs
@ -162,7 +162,7 @@ Intl.prototype = {
    Services.prefs.removeObserver("intl.accept_languages", this);
  },

-  observe(subject, topic, data) {
+  observe() {
    this.readPref();
  },

--- a/services/common/modules-testing/logging.sys.mjs
+++ b/services/common/modules-testing/logging.sys.mjs
@ -51,6 +51,6 @@ export function initTestLogging(level) {
  return logStats;
 }

-export function getTestLogger(component) {
+export function getTestLogger() {
  return Log.repository.getLogger("Testing");
 }
--- a/services/common/tests/unit/head_helpers.js
+++ b/services/common/tests/unit/head_helpers.js
@ -91,7 +91,7 @@ function do_check_throws_message(aFunc, aResult) {
 * @usage _("Hello World") -> prints "Hello World"
 * @usage _(1, 2, 3) -> prints "1 2 3"
 */
-var _ = function (some, debug, text, to) {
+var _ = function () {
  print(Array.from(arguments).join(" "));
 };

@ -192,7 +192,7 @@ var PACSystemSettings = {
  // each test gets a completely fresh setup.
  mainThreadOnly: true,
  PACURI: null,
-  getProxyForURI: function getProxyForURI(aURI) {
+  getProxyForURI: function getProxyForURI() {
    throw Components.Exception("", Cr.NS_ERROR_NOT_IMPLEMENTED);
  },
 };
@ -221,7 +221,7 @@ function getUptakeTelemetrySnapshot(component, source) {
  return (
    parentEvents
      // Transform raw event data to objects.
-      .map(([i, category, method, object, value, extras]) => {
+      .map(([, category, method, object, value, extras]) => {
        return { category, method, object, value, extras };
      })
      // Keep only for the specified component and source.
--- a/services/common/tests/unit/test_utils_namedTimer.js
+++ b/services/common/tests/unit/test_utils_namedTimer.js
@ -40,7 +40,7 @@ add_test(function test_delay() {
  const delay = 100;
  let that = {};
  let t0 = Date.now();
-  function callback(timer) {
+  function callback() {
    // Difference should be ~2*delay, but hard to predict on all platforms,
    // particularly Windows XP.
    Assert.ok(Date.now() - t0 > delay);
@ -57,7 +57,7 @@ add_test(function test_clear() {
  const delay = 0;
  let that = {};
  CommonUtils.namedTimer(
-    function callback(timer) {
+    function callback() {
      do_throw("Shouldn't fire!");
    },
    delay,
--- a/services/crypto/modules/WeaveCrypto.sys.mjs
+++ b/services/crypto/modules/WeaveCrypto.sys.mjs
@ -25,7 +25,7 @@ WeaveCrypto.prototype = {
      "nsISupportsWeakReference",
    ]),

-    observe(subject, topic, data) {
+    observe(subject, topic) {
      let self = this._self;
      self.log("Observed " + topic + " topic.");
      if (topic == "nsPref:changed") {
--- a/services/crypto/tests/unit/head_helpers.js
+++ b/services/crypto/tests/unit/head_helpers.js
@ -73,6 +73,6 @@ addResourceAlias();
 * @usage _("Hello World") -> prints "Hello World"
 * @usage _(1, 2, 3) -> prints "1 2 3"
 */
-var _ = function (some, debug, text, to) {
+var _ = function () {
  print(Array.from(arguments).join(" "));
 };
--- a/services/fxaccounts/FxAccountsClient.sys.mjs
+++ b/services/fxaccounts/FxAccountsClient.sys.mjs
@ -498,7 +498,7 @@ FxAccountsClient.prototype = {
   */
  accountExists(email) {
    return this.signIn(email, "").then(
-      cantHappen => {
+      () => {
        throw new Error("How did I sign in with an empty password?");
      },
      expectedError => {
--- a/services/fxaccounts/FxAccountsProfile.sys.mjs
+++ b/services/fxaccounts/FxAccountsProfile.sys.mjs
@ -52,7 +52,7 @@ FxAccountsProfile.prototype = {
  // making another request to determine if it is fresh or not.
  PROFILE_FRESHNESS_THRESHOLD: 120000, // 2 minutes

-  observe(subject, topic, data) {
+  observe(subject, topic) {
    // If we get a profile change notification from our webchannel it means
    // the user has just changed their profile via the web, so we want to
    // ignore our "freshness threshold"
--- a/services/fxaccounts/tests/mochitest/test_invalidEmailCase.html
+++ b/services/fxaccounts/tests/mochitest/test_invalidEmailCase.html
@ -49,7 +49,7 @@ MockStorage.prototype = Object.freeze({
  getOAuthTokens() {
    return Promise.resolve(null);
  },
-  setOAuthTokens(contents) {
+  setOAuthTokens() {
    return Promise.resolve();
  },
 });
--- a/services/fxaccounts/tests/xpcshell/test_accounts.js
+++ b/services/fxaccounts/tests/xpcshell/test_accounts.js
@ -120,7 +120,7 @@ function MockFxAccountsClient() {

  // mock calls up to the auth server to determine whether the
  // user account has been verified
-  this.recoveryEmailStatus = async function (sessionToken) {
+  this.recoveryEmailStatus = async function () {
    // simulate a call to /recovery_email/status
    return {
      email: this._email,
@ -139,7 +139,7 @@ function MockFxAccountsClient() {
    return !this._deletedOnServer;
  };

-  this.accountKeys = function (keyFetchToken) {
+  this.accountKeys = function () {
    return new Promise(resolve => {
      do_timeout(50, () => {
        resolve({
@ -188,7 +188,7 @@ Object.setPrototypeOf(
 * mock the now() method, so that we can simulate the passing of
 * time and verify that signatures expire correctly.
 */
-function MockFxAccounts(credentials = null) {
+function MockFxAccounts() {
  let result = new FxAccounts({
    VERIFICATION_POLL_TIMEOUT_INITIAL: 100, // 100ms

@ -453,10 +453,10 @@ add_test(function test_polling_timeout() {

  fxa.setSignedInUser(test_user).then(() => {
    p.then(
-      success => {
+      () => {
        do_throw("this should not succeed");
      },
-      fail => {
+      () => {
        removeObserver();
        fxa.signOut().then(run_next_test);
      }
@ -471,7 +471,7 @@ add_task(async function test_onverified_once() {

  let numNotifications = 0;

-  function observe(aSubject, aTopic, aData) {
+  function observe() {
    numNotifications += 1;
  }
  Services.obs.addObserver(observe, ONVERIFIED_NOTIFICATION);
@ -971,17 +971,17 @@ add_test(function test_fetchAndUnwrapAndDeriveKeys_no_token() {

  makeObserver(ONLOGOUT_NOTIFICATION, function () {
    log.debug("test_fetchAndUnwrapKeys_no_token observed logout");
-    fxa._internal.getUserAccountData().then(user2 => {
+    fxa._internal.getUserAccountData().then(() => {
      fxa._internal.abortExistingFlow().then(run_next_test);
    });
  });

  fxa
    .setSignedInUser(user)
-    .then(user2 => {
+    .then(() => {
      return fxa.keys._fetchAndUnwrapAndDeriveKeys();
    })
-    .catch(error => {
+    .catch(() => {
      log.info("setSignedInUser correctly rejected");
    });
 });
@ -1272,11 +1272,7 @@ add_task(async function test_getOAuthTokenCachedScopeNormalization() {
  let numOAuthTokenCalls = 0;

  let client = fxa._internal.fxAccountsClient;
-  client.accessTokenWithSessionToken = async (
-    _sessionTokenHex,
-    _clientId,
-    scopeString
-  ) => {
+  client.accessTokenWithSessionToken = async (_sessionTokenHex, _clientId) => {
    numOAuthTokenCalls++;
    return MOCK_TOKEN_RESPONSE;
  };
--- a/services/fxaccounts/tests/xpcshell/test_accounts_device_registration.js
+++ b/services/fxaccounts/tests/xpcshell/test_accounts_device_registration.js
@ -80,7 +80,7 @@ function MockFxAccountsClient(device) {

  // mock calls up to the auth server to determine whether the
  // user account has been verified
-  this.recoveryEmailStatus = function (sessionToken) {
+  this.recoveryEmailStatus = function () {
    // simulate a call to /recovery_email/status
    return Promise.resolve({
      email: this._email,
@ -104,8 +104,7 @@ function MockFxAccountsClient(device) {
    return Promise.resolve(!!uid && !this._deletedOnServer);
  };

-  this.registerDevice = (st, name, type) =>
-    Promise.resolve({ id: device.id, name });
+  this.registerDevice = (st, name) => Promise.resolve({ id: device.id, name });
  this.updateDevice = (st, id, name) => Promise.resolve({ id, name });
  this.signOut = () => Promise.resolve({});
  this.getDeviceList = st =>
@ -655,7 +654,7 @@ add_task(async function test_verification_updates_registration() {
    };
  });

-  fxa._internal.checkEmailStatus = async function (sessionToken) {
+  fxa._internal.checkEmailStatus = async function () {
    credentials.verified = true;
    return credentials;
  };
@ -792,7 +791,7 @@ add_task(async function test_refreshDeviceList() {
  };
  const deviceListUpdateObserver = {
    count: 0,
-    observe(subject, topic, data) {
+    observe() {
      this.count++;
    },
  };
--- a/services/fxaccounts/tests/xpcshell/test_commands.js
+++ b/services/fxaccounts/tests/xpcshell/test_commands.js
@ -174,7 +174,7 @@ add_task(async function test_sendtab_receive() {

  const fxai = FxaInternalMock();
  const sendTab = new SendTab(commands, fxai);
-  sendTab._encrypt = (bytes, device) => {
+  sendTab._encrypt = bytes => {
    return bytes;
  };
  sendTab._decrypt = bytes => {
@ -387,7 +387,7 @@ add_task(async function test_commands_handleCommands() {
    },
  };
  const commands = new FxAccountsCommands(fxAccounts);
-  commands.sendTab.handle = (sender, data, reason) => {
+  commands.sendTab.handle = () => {
    return {
      title: "testTitle",
      uri: "https://testURI",
@ -436,7 +436,7 @@ add_task(async function test_commands_handleCommands_invalid_tab() {
    },
  };
  const commands = new FxAccountsCommands(fxAccounts);
-  commands.sendTab.handle = (sender, data, reason) => {
+  commands.sendTab.handle = () => {
    return {
      title: "badUriTab",
      uri: "file://path/to/pdf",
--- a/services/fxaccounts/tests/xpcshell/test_oauth_token_storage.js
+++ b/services/fxaccounts/tests/xpcshell/test_oauth_token_storage.js
@ -94,7 +94,7 @@ Object.setPrototypeOf(
  FxAccountsClient.prototype
 );

-function MockFxAccounts(device = {}) {
+function MockFxAccounts() {
  return new FxAccounts({
    fxAccountsClient: new MockFxAccountsClient(),
    newAccountState(credentials) {
--- a/services/fxaccounts/tests/xpcshell/test_pairing.js
+++ b/services/fxaccounts/tests/xpcshell/test_pairing.js
@ -61,7 +61,7 @@ const fxAccounts = {
  },
  _internal: {
    keys: {
-      getKeyForScope(scope) {
+      getKeyForScope() {
        return {
          kid: "123456",
          k: KSYNC,
--- a/services/fxaccounts/tests/xpcshell/test_profile.js
+++ b/services/fxaccounts/tests/xpcshell/test_profile.js
@ -142,10 +142,10 @@ add_test(function fetchAndCacheProfile_always_bumps_cachedAt() {
  profile._cachedAt = 12345;

  return profile._fetchAndCacheProfile().then(
-    result => {
+    () => {
      do_throw("Should not succeed");
    },
-    err => {
+    () => {
      Assert.notEqual(profile._cachedAt, 12345, "cachedAt has been bumped");
      run_next_test();
    }
@ -164,7 +164,7 @@ add_test(function fetchAndCacheProfile_sendsETag() {
  };
  let profile = CreateFxAccountsProfile(fxa, client);

-  return profile._fetchAndCacheProfile().then(result => {
+  return profile._fetchAndCacheProfile().then(() => {
    run_next_test();
  });
 });
@ -282,7 +282,7 @@ add_test(function fetchAndCacheProfile_alreadyCached() {
  };

  let profile = CreateFxAccountsProfile(fxa, client);
-  profile._cacheProfile = function (toCache) {
+  profile._cacheProfile = function () {
    do_throw("This method should not be called.");
  };

@ -614,7 +614,7 @@ add_test(function getProfile_has_cached_fetch_deleted() {

  // instead of checking this in a mocked "save" function, just check after the
  // observer
-  makeObserver(ON_PROFILE_CHANGE_NOTIFICATION, function (subject, topic, data) {
+  makeObserver(ON_PROFILE_CHANGE_NOTIFICATION, function () {
    profile.getProfile().then(profileData => {
      Assert.equal(null, profileData.avatar);
      run_next_test();
--- a/services/fxaccounts/tests/xpcshell/test_profile_client.js
+++ b/services/fxaccounts/tests/xpcshell/test_profile_client.js
@ -39,7 +39,7 @@ let mockResponse = function (response) {
          Request.ifNoneMatchSet = true;
        }
      },
-      async dispatch(method, payload) {
+      async dispatch() {
        this.response = response;
        return this.response;
      },
@ -74,7 +74,7 @@ let mockResponseError = function (error) {
  return function () {
    return {
      setHeader() {},
-      async dispatch(method, payload) {
+      async dispatch() {
        throw error;
      },
    };
@ -221,7 +221,7 @@ add_test(function server401ResponseThenSuccess() {
  let numRequests = 0;
  let numAuthHeaders = 0;
  // Like mockResponse but we want access to headers etc.
-  client._Request = function (requestUri) {
+  client._Request = function () {
    return {
      setHeader(name, value) {
        if (name == "Authorization") {
@ -229,7 +229,7 @@ add_test(function server401ResponseThenSuccess() {
          Assert.equal(value, "Bearer " + lastToken);
        }
      },
-      async dispatch(method, payload) {
+      async dispatch() {
        this.response = responses[numRequests];
        ++numRequests;
        return this.response;
@ -283,7 +283,7 @@ add_test(function server401ResponsePersists() {

  let numRequests = 0;
  let numAuthHeaders = 0;
-  client._Request = function (requestUri) {
+  client._Request = function () {
    return {
      setHeader(name, value) {
        if (name == "Authorization") {
@ -291,7 +291,7 @@ add_test(function server401ResponsePersists() {
          Assert.equal(value, "Bearer " + lastToken);
        }
      },
-      async dispatch(method, payload) {
+      async dispatch() {
        this.response = response;
        ++numRequests;
        return this.response;
--- a/services/fxaccounts/tests/xpcshell/test_push_service.js
+++ b/services/fxaccounts/tests/xpcshell/test_push_service.js
@ -179,7 +179,7 @@ add_test(function observePushTopicDeviceConnected() {
      return this;
    },
  };
-  let obs = (subject, topic, data) => {
+  let obs = (subject, topic) => {
    Services.obs.removeObserver(obs, topic);
    run_next_test();
  };
@ -392,7 +392,7 @@ add_test(function observePushTopicProfileUpdated() {
      return this;
    },
  };
-  let obs = (subject, topic, data) => {
+  let obs = (subject, topic) => {
    Services.obs.removeObserver(obs, topic);
    run_next_test();
  };
--- a/services/fxaccounts/tests/xpcshell/test_storage_manager.js
+++ b/services/fxaccounts/tests/xpcshell/test_storage_manager.js
@ -62,7 +62,7 @@ MockedSecureStorage.prototype = {
  // "TypeError: this.STORAGE_LOCKED is not a constructor"
  STORAGE_LOCKED: function () {},
  /* eslint-enable object-shorthand */
-  async get(uid, email) {
+  async get() {
    this.fetchCount++;
    if (this.locked) {
      throw new this.STORAGE_LOCKED();
--- a/services/fxaccounts/tests/xpcshell/test_web_channel.js
+++ b/services/fxaccounts/tests/xpcshell/test_web_channel.js
@ -202,7 +202,7 @@ add_test(function test_error_message_remove_profile_path() {
  const toTest = Object.keys(errors).length;
  for (const key in errors) {
    let error = errors[key];
-    channel._channel.send = (message, context) => {
+    channel._channel.send = message => {
      equal(
        message.data.error.message,
        error.expected,
@ -403,7 +403,7 @@ add_test(function test_fxa_status_message() {
  });

  channel._channel = {
-    send(response, sendingContext) {
+    send(response) {
      Assert.equal(response.command, "fxaccounts:fxa_status");
      Assert.equal(response.messageId, 123);

@ -513,7 +513,7 @@ add_task(async function test_helpers_login_set_previous_account_name_hash() {
  let helpers = new FxAccountsWebChannelHelpers({
    fxAccounts: {
      _internal: {
-        setSignedInUser(accountData) {
+        setSignedInUser() {
          return new Promise(resolve => {
            // previously signed in user preference is updated.
            Assert.equal(
@ -554,7 +554,7 @@ add_task(
    let helpers = new FxAccountsWebChannelHelpers({
      fxAccounts: {
        _internal: {
-          setSignedInUser(accountData) {
+          setSignedInUser() {
            return new Promise(resolve => {
              // previously signed in user preference should not be updated.
              Assert.equal(
--- a/services/settings/IDBHelpers.sys.mjs
+++ b/services/settings/IDBHelpers.sys.mjs
@ -108,7 +108,7 @@ function executeIDB(db, storeNames, mode, callback, desc) {
          desc || "execute()"
        )
      );
-    transaction.oncomplete = event => resolve(result);
+    transaction.oncomplete = () => resolve(result);
    // Simplify access to a single datastore:
    if (stores.length == 1) {
      stores = stores[0];
--- a/services/settings/RemoteSettingsClient.sys.mjs
+++ b/services/settings/RemoteSettingsClient.sys.mjs
@ -34,7 +34,7 @@ ChromeUtils.defineLazyGetter(lazy, "console", () => lazy.Utils.log);
 function cacheProxy(target) {
  const cache = new Map();
  return new Proxy(target, {
-    get(target, prop, receiver) {
+    get(target, prop) {
      if (!cache.has(prop)) {
        cache.set(prop, target[prop]);
      }
--- a/services/settings/RemoteSettingsComponents.sys.mjs
+++ b/services/settings/RemoteSettingsComponents.sys.mjs
@ -15,7 +15,7 @@ RemoteSettingsTimer.prototype = {
  contractID: "@mozilla.org/services/settings;1",

  // By default, this timer fires once every 24 hours. See the "services.settings.poll_interval" pref.
-  notify(timer) {
+  notify() {
    lazy.RemoteSettings.pollChanges({ trigger: "timer" }).catch(e =>
      console.error(e)
    );
--- a/services/settings/test/unit/test_attachments_downloader.js
+++ b/services/settings/test/unit/test_attachments_downloader.js
@ -68,9 +68,9 @@ async function clear_state() {

  downloader = new Downloader("main", "some-collection");
  const dummyCacheImpl = {
-    get: async attachmentId => {},
-    set: async (attachmentId, attachment) => {},
-    delete: async attachmentId => {},
+    get: async () => {},
+    set: async () => {},
+    delete: async () => {},
  };
  // The download() method requires a cacheImpl, but the Downloader
  // class does not have one. Define a dummy no-op one.
@ -388,7 +388,7 @@ async function doTestDownloadCacheImpl({ simulateCorruption }) {
        throw new Error("Simulation of corrupted cache (write)");
      }
    },
-    async delete(attachmentId) {},
+    async delete() {},
  };
  Object.defineProperty(downloader, "cacheImpl", { value: cacheImpl });

--- a/services/settings/test/unit/test_remote_settings.js
+++ b/services/settings/test/unit/test_remote_settings.js
@ -545,7 +545,7 @@ add_task(async function test_get_does_not_verify_signature_if_load_dump() {

  let called;
  clientWithDump._verifier = {
-    async asyncVerifyContentSignature(serialized, signature) {
+    async asyncVerifyContentSignature() {
      called = true;
      return true;
    },
@ -583,7 +583,7 @@ add_task(
    const backup = clientWithDump._verifier;
    let callCount = 0;
    clientWithDump._verifier = {
-      async asyncVerifyContentSignature(serialized, signature) {
+      async asyncVerifyContentSignature() {
        callCount++;
        return true;
      },
@ -640,7 +640,7 @@ add_task(

    let called;
    clientWithDump._verifier = {
-      async asyncVerifyContentSignature(serialized, signature) {
+      async asyncVerifyContentSignature() {
        called = true;
        return true;
      },
@ -1174,7 +1174,7 @@ add_task(clear_state);

 add_task(async function test_sync_event_is_not_sent_from_get_when_no_dump() {
  let called = false;
-  client.on("sync", e => {
+  client.on("sync", () => {
    called = true;
  });

--- a/services/settings/test/unit/test_remote_settings_poll.js
+++ b/services/settings/test/unit/test_remote_settings_poll.js
@ -188,7 +188,7 @@ add_task(async function test_check_success() {
  // Ensure that the remote-settings:changes-poll-end notification works
  let notificationObserved = false;
  const observer = {
-    observe(aSubject, aTopic, aData) {
+    observe() {
      Services.obs.removeObserver(this, "remote-settings:changes-poll-end");
      notificationObserved = true;
    },
@ -258,7 +258,7 @@ add_task(async function test_update_timer_interface() {
  await new Promise(resolve => {
    const e = "remote-settings:changes-poll-end";
    const changesPolledObserver = {
-      observe(aSubject, aTopic, aData) {
+      observe() {
        Services.obs.removeObserver(this, e);
        resolve();
      },
@ -288,7 +288,7 @@ add_task(async function test_check_up_to_date() {
  // Ensure that the remote-settings:changes-poll-end notification is sent.
  let notificationObserved = false;
  const observer = {
-    observe(aSubject, aTopic, aData) {
+    observe() {
      Services.obs.removeObserver(this, "remote-settings:changes-poll-end");
      notificationObserved = true;
    },
@ -686,7 +686,7 @@ add_task(async function test_server_error() {

  let notificationObserved = false;
  const observer = {
-    observe(aSubject, aTopic, aData) {
+    observe() {
      Services.obs.removeObserver(this, "remote-settings:changes-poll-end");
      notificationObserved = true;
    },
@ -807,7 +807,7 @@ add_task(async function test_client_error() {

  let notificationsObserved = [];
  const observer = {
-    observe(aSubject, aTopic, aData) {
+    observe(aSubject, aTopic) {
      Services.obs.removeObserver(this, aTopic);
      notificationsObserved.push([aTopic, aSubject.wrappedJSObject]);
    },
@ -935,7 +935,7 @@ add_task(
    // Wait for the "sync-broken-error" notification.
    let notificationObserved = false;
    const observer = {
-      observe(aSubject, aTopic, aData) {
+      observe() {
        notificationObserved = true;
      },
    };
--- a/services/settings/test/unit/test_remote_settings_signatures.js
+++ b/services/settings/test/unit/test_remote_settings_signatures.js
@ -487,7 +487,7 @@ add_task(async function test_check_synchronization_with_signatures() {
  );

  let syncEventSent = false;
-  client.on("sync", ({ data }) => {
+  client.on("sync", () => {
    syncEventSent = true;
  });

@ -542,7 +542,7 @@ add_task(async function test_check_synchronization_with_signatures() {
  registerHandlers(badSigGoodOldResponses);

  syncEventSent = false;
-  client.on("sync", ({ data }) => {
+  client.on("sync", () => {
    syncEventSent = true;
  });

@ -783,7 +783,7 @@ add_task(async function test_check_synchronization_with_signatures() {
  const sigCalls = [];
  let i = 0;
  client._verifier = {
-    async asyncVerifyContentSignature(serialized, signature) {
+    async asyncVerifyContentSignature(serialized) {
      sigCalls.push(serialized);
      console.log(`verify call ${i}`);
      return [
--- a/services/settings/test/unit/test_remote_settings_worker.js
+++ b/services/settings/test/unit/test_remote_settings_worker.js
@ -82,8 +82,8 @@ add_task(async function test_throws_error_if_worker_fails_async() {
  // should be reported to the caller.
  await new Promise((resolve, reject) => {
    const request = indexedDB.deleteDatabase("remote-settings");
-    request.onsuccess = event => resolve();
-    request.onblocked = event => reject(new Error("Cannot delete DB"));
+    request.onsuccess = () => resolve();
+    request.onblocked = () => reject(new Error("Cannot delete DB"));
    request.onerror = event => reject(event.target.error);
  });
  let error;
--- a/services/settings/test/unit/test_shutdown_handling.js
+++ b/services/settings/test/unit/test_shutdown_handling.js
@ -41,7 +41,7 @@ add_task(async function test_shutdown_abort_after_start() {
        const request = store
          .index("cid")
          .openCursor(IDBKeyRange.only("foopydoo/foo"));
-        request.onsuccess = event => {
+        request.onsuccess = () => {
          makeRequest();
        };
      }
@ -74,7 +74,7 @@ add_task(async function test_shutdown_immediate_abort() {
      let request = store
        .index("cid")
        .openCursor(IDBKeyRange.only("foopydoo/foo"));
-      request.onsuccess = event => {
+      request.onsuccess = () => {
        // Abort immediately.
        Database._shutdownHandler();
        request = store
--- a/services/sync/Weave.sys.mjs
+++ b/services/sync/Weave.sys.mjs
@ -156,7 +156,7 @@ AboutWeaveLog.prototype = {
    "nsISupportsWeakReference",
  ]),

-  getURIFlags(aURI) {
+  getURIFlags() {
    return 0;
  },

--- a/services/sync/modules-testing/fakeservices.sys.mjs
+++ b/services/sync/modules-testing/fakeservices.sys.mjs
@ -29,7 +29,7 @@ export function FakeFilesystemService(contents) {
    self.fakeContents["weave/" + filePath + ".json"] = JSON.stringify(json);
  };

-  Utils.jsonLoad = async function jsonLoad(filePath, that) {
+  Utils.jsonLoad = async function jsonLoad(filePath) {
    let obj;
    let json = self.fakeContents["weave/" + filePath + ".json"];
    if (json) {
@ -38,14 +38,14 @@ export function FakeFilesystemService(contents) {
    return obj;
  };

-  Utils.jsonMove = function jsonMove(aFrom, aTo, that) {
+  Utils.jsonMove = function jsonMove(aFrom, aTo) {
    const fromPath = "weave/" + aFrom + ".json";
    self.fakeContents["weave/" + aTo + ".json"] = self.fakeContents[fromPath];
    delete self.fakeContents[fromPath];
    return Promise.resolve();
  };

-  Utils.jsonRemove = function jsonRemove(filePath, that) {
+  Utils.jsonRemove = function jsonRemove(filePath) {
    delete self.fakeContents["weave/" + filePath + ".json"];
    return Promise.resolve();
  };
@ -79,19 +79,17 @@ export function FakeCryptoService() {
  delete Weave.Crypto; // get rid of the getter first
  Weave.Crypto = this;

-  RawCryptoWrapper.prototype.ciphertextHMAC = function ciphertextHMAC(
-    keyBundle
-  ) {
+  RawCryptoWrapper.prototype.ciphertextHMAC = function ciphertextHMAC() {
    return fakeSHA256HMAC(this.ciphertext);
  };
 }

 FakeCryptoService.prototype = {
-  async encrypt(clearText, symmetricKey, iv) {
+  async encrypt(clearText) {
    return clearText;
  },

-  async decrypt(cipherText, symmetricKey, iv) {
+  async decrypt(cipherText) {
    return cipherText;
  },

@ -104,7 +102,7 @@ FakeCryptoService.prototype = {
    return btoa("fake-fake-fake-random-iv");
  },

-  expandData: function expandData(data, len) {
+  expandData: function expandData(data) {
    return data;
  },

--- a/services/sync/modules-testing/fxa_utils.sys.mjs
+++ b/services/sync/modules-testing/fxa_utils.sys.mjs
@ -23,7 +23,7 @@ export var initializeIdentityWithTokenServerResponse = function (response) {
  }

  // A mock request object.
-  function MockRESTRequest(url) {}
+  function MockRESTRequest() {}
  MockRESTRequest.prototype = {
    _log: requestLog,
    setHeader() {},
--- a/services/sync/modules/UIState.sys.mjs
+++ b/services/sync/modules/UIState.sys.mjs
@ -87,7 +87,7 @@ const UIStateInternal = {
    this._initialized = false;
  },

-  observe(subject, topic, data) {
+  observe(subject, topic) {
    switch (topic) {
      case "weave:service:sync:start":
        this.toggleSyncActivity(true);
--- a/services/sync/modules/bridged_engine.sys.mjs
+++ b/services/sync/modules/bridged_engine.sys.mjs
@ -43,7 +43,7 @@ class BridgedStore {
    this._batchChunkSize = 500;
  }

-  async applyIncomingBatch(records, countTelemetry) {
+  async applyIncomingBatch(records) {
    for (let chunk of lazy.PlacesUtils.chunkArray(
      records,
      this._batchChunkSize
--- a/services/sync/modules/collection_validator.sys.mjs
+++ b/services/sync/modules/collection_validator.sys.mjs
@ -114,13 +114,13 @@ export class CollectionValidator {

  // Return whether or not a server item should be present on the client. Expected
  // to be overridden.
-  clientUnderstands(item) {
+  clientUnderstands() {
    return true;
  }

  // Return whether or not a client item should be present on the server. Expected
  // to be overridden
-  async syncedByClient(item) {
+  async syncedByClient() {
    return true;
  }

--- a/services/sync/modules/engines.sys.mjs
+++ b/services/sync/modules/engines.sys.mjs
@ -113,12 +113,12 @@ Tracker.prototype = {
  },

  // Also unsupported.
-  async addChangedID(id, when) {
+  async addChangedID() {
    throw new TypeError("Can't add changed ID to this tracker");
  },

  // Ditto.
-  async removeChangedID(...ids) {
+  async removeChangedID() {
    throw new TypeError("Can't remove changed IDs from this tracker");
  },

@ -155,7 +155,7 @@ Tracker.prototype = {
  // Override these in your subclasses.
  onStart() {},
  onStop() {},
-  async observe(subject, topic, data) {},
+  async observe() {},

  engineIsEnabled() {
    if (!this.engine) {
@ -437,7 +437,7 @@ Store.prototype = {
   * @param record
   *        The store record to create an item from
   */
-  async create(record) {
+  async create() {
    throw new Error("override create in a subclass");
  },

@ -450,7 +450,7 @@ Store.prototype = {
   * @param record
   *        The store record to delete an item from
   */
-  async remove(record) {
+  async remove() {
    throw new Error("override remove in a subclass");
  },

@ -463,7 +463,7 @@ Store.prototype = {
   * @param record
   *        The record to use to update an item from
   */
-  async update(record) {
+  async update() {
    throw new Error("override update in a subclass");
  },

@ -477,7 +477,7 @@ Store.prototype = {
   *         string record ID
   * @return boolean indicating whether record exists locally
   */
-  async itemExists(id) {
+  async itemExists() {
    throw new Error("override itemExists in a subclass");
  },

@ -495,7 +495,7 @@ Store.prototype = {
   *         constructor for the newly-created record.
   * @return record type for this engine
   */
-  async createRecord(id, collection) {
+  async createRecord() {
    throw new Error("override createRecord in a subclass");
  },

@ -507,7 +507,7 @@ Store.prototype = {
   * @param  newID
   *         string new record ID
   */
-  async changeItemID(oldID, newID) {
+  async changeItemID() {
    throw new Error("override changeItemID in a subclass");
  },

@ -1040,7 +1040,7 @@ SyncEngine.prototype = {
   * Note: Overriding engines must take resyncs into account -- score will not
   * be cleared.
   */
-  shouldSkipSync(syncReason) {
+  shouldSkipSync() {
    return false;
  },

@ -1550,7 +1550,7 @@ SyncEngine.prototype = {
  // Indicates whether an incoming item should be deleted from the server at
  // the end of the sync. Engines can override this method to clean up records
  // that shouldn't be on the server.
-  _shouldDeleteRemotely(remoteItem) {
+  _shouldDeleteRemotely() {
    return false;
  },

@ -1560,7 +1560,7 @@ SyncEngine.prototype = {
   *
   * @return GUID of the similar item; falsy otherwise
   */
-  async _findDupe(item) {
+  async _findDupe() {
    // By default, assume there's no dupe items for the engine
  },

@ -1568,7 +1568,7 @@ SyncEngine.prototype = {
   * Called before a remote record is discarded due to failed reconciliation.
   * Used by bookmark sync to merge folder child orders.
   */
-  beforeRecordDiscard(localRecord, remoteRecord, remoteIsNewer) {},
+  beforeRecordDiscard() {},

  // Called when the server has a record marked as deleted, but locally we've
  // changed it more recently than the deletion. If we return false, the
@ -1576,7 +1576,7 @@ SyncEngine.prototype = {
  // record to the server -- any extra work that's needed as part of this
  // process should be done at this point (such as mark the record's parent
  // for reuploading in the case of bookmarks).
-  async _shouldReviveRemotelyDeletedRecord(remoteItem) {
+  async _shouldReviveRemotelyDeletedRecord() {
    return true;
  },

@ -1948,7 +1948,7 @@ SyncEngine.prototype = {
    }
  },

-  async _onRecordsWritten(succeeded, failed, serverModifiedTime) {
+  async _onRecordsWritten() {
    // Implement this method to take specific actions against successfully
    // uploaded records and failed records.
  },
--- a/services/sync/modules/engines/bookmarks.sys.mjs
+++ b/services/sync/modules/engines/bookmarks.sys.mjs
@ -513,7 +513,7 @@ BookmarksEngine.prototype = {
    await this._apply();
  },

-  async _reconcile(item) {
+  async _reconcile() {
    return true;
  },

@ -752,7 +752,7 @@ BookmarksStore.prototype = {
    });
  },

-  async applyIncomingBatch(records, countTelemetry) {
+  async applyIncomingBatch(records) {
    let buf = await this.ensureOpenMirror();
    for (let chunk of lazy.PlacesUtils.chunkArray(
      records,
@ -921,11 +921,11 @@ Object.setPrototypeOf(BookmarksTracker.prototype, Tracker.prototype);
 class BookmarksChangeset extends Changeset {
  // Only `_reconcile` calls `getModifiedTimestamp` and `has`, and the engine
  // does its own reconciliation.
-  getModifiedTimestamp(id) {
+  getModifiedTimestamp() {
    throw new Error("Don't use timestamps to resolve bookmark conflicts");
  }

-  has(id) {
+  has() {
    throw new Error("Don't use the changeset to resolve bookmark conflicts");
  }

--- a/services/sync/modules/engines/clients.sys.mjs
+++ b/services/sync/modules/engines/clients.sys.mjs
@ -1107,7 +1107,7 @@ ClientsTracker.prototype = {
    Svc.Obs.remove("fxaccounts:new_device_id", this.asyncObserver);
  },

-  async observe(subject, topic, data) {
+  async observe(subject, topic) {
    switch (topic) {
      case "nsPref:changed":
        this._log.debug("client.name preference changed");
--- a/services/sync/modules/engines/extension-storage.sys.mjs
+++ b/services/sync/modules/engines/extension-storage.sys.mjs
@ -124,7 +124,7 @@ ExtensionStorageEngineBridge.prototype = {
  },

  _takeMigrationInfo() {
-    return new Promise((resolve, reject) => {
+    return new Promise(resolve => {
      this.component
        .QueryInterface(Ci.mozIExtensionStorageArea)
        .takeMigrationInfo({
@ -291,7 +291,7 @@ ExtensionStorageTracker.prototype = {
    lazy.Svc.Obs.remove("ext.storage.sync-changed", this.asyncObserver);
  },

-  async observe(subject, topic, data) {
+  async observe(subject, topic) {
    if (this.ignoreAll) {
      return;
    }
--- a/services/sync/modules/engines/forms.sys.mjs
+++ b/services/sync/modules/engines/forms.sys.mjs
@ -189,7 +189,7 @@ FormStore.prototype = {
    await this._processChange(change);
  },

-  async update(record) {
+  async update() {
    this._log.trace("Ignoring form record update request!");
  },

--- a/services/sync/modules/engines/prefs.sys.mjs
+++ b/services/sync/modules/engines/prefs.sys.mjs
@ -386,7 +386,7 @@ PrefStore.prototype = {
    return allprefs;
  },

-  async changeItemID(oldID, newID) {
+  async changeItemID() {
    this._log.trace("PrefStore GUID is constant!");
  },

@ -406,11 +406,11 @@ PrefStore.prototype = {
    return record;
  },

-  async create(record) {
+  async create() {
    this._log.trace("Ignoring create request");
  },

-  async remove(record) {
+  async remove() {
    this._log.trace("Ignoring remove request");
  },

--- a/services/sync/modules/engines/tabs.sys.mjs
+++ b/services/sync/modules/engines/tabs.sys.mjs
@ -430,7 +430,7 @@ export const TabProvider = {
        .then(iconData => {
          thisTab.icon = iconData.uri.spec;
        })
-        .catch(ex => {
+        .catch(() => {
          log.trace(
            `Failed to fetch favicon for ${url}`,
            thisTab.urlHistory[0]
@ -503,7 +503,7 @@ TabTracker.prototype = {
    }
  },

-  async observe(subject, topic, data) {
+  async observe(subject, topic) {
    switch (topic) {
      case "domwindowopened":
        let onLoad = () => {
--- a/services/sync/modules/record.sys.mjs
+++ b/services/sync/modules/record.sys.mjs
@ -182,7 +182,7 @@ RawCryptoWrapper.prototype = {
   * @param   {Cleartext} outgoingCleartext The cleartext to upload.
   * @returns {String}                      The serialized cleartext.
   */
-  transformBeforeEncrypt(outgoingCleartext) {
+  transformBeforeEncrypt() {
    throw new TypeError("Override to stringify outgoing records");
  },

@ -194,7 +194,7 @@ RawCryptoWrapper.prototype = {
   * @param   {String} incomingCleartext The decrypted cleartext string.
   * @returns {Cleartext}                The parsed cleartext.
   */
-  transformAfterDecrypt(incomingCleartext) {
+  transformAfterDecrypt() {
    throw new TypeError("Override to parse incoming records");
  },

@ -527,7 +527,7 @@ CollectionKeyManager.prototype = {
  /**
   * Create a WBO for the current keys.
   */
-  asWBO(collection, id) {
+  asWBO() {
    return this._makeWBO(this._collections, this._default);
  },

--- a/services/sync/modules/sync_auth.sys.mjs
+++ b/services/sync/modules/sync_auth.sys.mjs
@ -164,7 +164,7 @@ SyncAuthManager.prototype = {
    this._token = null;
  },

-  async observe(subject, topic, data) {
+  async observe(subject, topic) {
    this._log.debug("observed " + topic);
    if (!this.username) {
      this._log.info("Sync is not configured, so ignoring the notification");
@ -276,7 +276,7 @@ SyncAuthManager.prototype = {
   * allows us to avoid a network request for when we actually need the
   * migration info.
   */
-  prefetchMigrationSentinel(service) {
+  prefetchMigrationSentinel() {
    // nothing to do here until we decide to migrate away from FxA.
  },

--- a/services/sync/tests/unit/head_helpers.js
+++ b/services/sync/tests/unit/head_helpers.js
@ -530,8 +530,8 @@ async function sync_engine_and_validate_telem(

 // Returns a promise that resolves once the specified observer notification
 // has fired.
-function promiseOneObserver(topic, callback) {
-  return new Promise((resolve, reject) => {
+function promiseOneObserver(topic) {
+  return new Promise(resolve => {
    let observer = function (subject, data) {
      Svc.Obs.remove(topic, observer);
      resolve({ subject, data });
--- a/services/sync/tests/unit/head_http_server.js
+++ b/services/sync/tests/unit/head_http_server.js
@ -687,8 +687,8 @@ function track_collections_helper() {
 * prototype, and override as appropriate.
 */
 var SyncServerCallback = {
-  onCollectionDeleted: function onCollectionDeleted(user, collection) {},
-  onItemDeleted: function onItemDeleted(user, collection, wboID) {},
+  onCollectionDeleted: function onCollectionDeleted() {},
+  onItemDeleted: function onItemDeleted() {},

  /**
   * Called at the top of every request.
@ -699,7 +699,7 @@ var SyncServerCallback = {
   * must be taken to not screw with the response body or headers that may
   * conflict with normal operation of this server.
   */
-  onRequest: function onRequest(request, response) {},
+  onRequest: function onRequest() {},
 };

 /**
--- a/services/sync/tests/unit/test_addon_utils.js
+++ b/services/sync/tests/unit/test_addon_utils.js
@ -119,7 +119,7 @@ add_task(async function test_source_uri_rewrite() {

  let installCalled = false;
  Object.getPrototypeOf(AddonUtils).installAddonFromSearchResult =
-    async function testInstallAddon(addon, metadata) {
+    async function testInstallAddon(addon) {
      Assert.equal(
        SERVER_ADDRESS + "/require.xpi?src=sync",
        addon.sourceURI.spec
--- a/services/sync/tests/unit/test_addons_validator.js
+++ b/services/sync/tests/unit/test_addons_validator.js
@ -49,7 +49,7 @@ function getDummyServerAndClient() {
 add_task(async function test_valid() {
  let { server, client } = getDummyServerAndClient();
  let validator = new AddonValidator({
-    _findDupe(item) {
+    _findDupe() {
      return null;
    },
    isAddonSyncable(item) {
--- a/services/sync/tests/unit/test_bookmark_tracker.js
+++ b/services/sync/tests/unit/test_bookmark_tracker.js
@ -778,7 +778,7 @@ add_task(async function test_onFaviconChanged() {
        iconURI,
        true,
        PlacesUtils.favicons.FAVICON_LOAD_NON_PRIVATE,
-        (uri, dataLen, data, mimeType) => {
+        () => {
          resolve();
        },
        Services.scriptSecurityManager.getSystemPrincipal()
--- a/services/sync/tests/unit/test_clients_engine.js
+++ b/services/sync/tests/unit/test_clients_engine.js
@ -779,7 +779,7 @@ add_task(async function test_filter_duplicate_names() {

    // Check that a subsequent Sync doesn't report anything as being processed.
    let counts;
-    Svc.Obs.add("weave:engine:sync:applied", function observe(subject, data) {
+    Svc.Obs.add("weave:engine:sync:applied", function observe(subject) {
      Svc.Obs.remove("weave:engine:sync:applied", observe);
      counts = subject;
    });
--- a/services/sync/tests/unit/test_declined.js
+++ b/services/sync/tests/unit/test_declined.js
@ -79,7 +79,7 @@ add_task(async function testOldMeta() {

  let declinedEngines = new DeclinedEngines(Service);

-  function onNotDeclined(subject, topic, data) {
+  function onNotDeclined(subject) {
    Observers.remove("weave:engines:notdeclined", onNotDeclined);
    Assert.ok(
      subject.undecided.has("actual"),
@ -129,7 +129,7 @@ add_task(async function testDeclinedMeta() {

  let declinedEngines = new DeclinedEngines(Service);

-  function onNotDeclined(subject, topic, data) {
+  function onNotDeclined(subject) {
    Observers.remove("weave:engines:notdeclined", onNotDeclined);
    Assert.ok(
      subject.undecided.has("actual"),
--- a/services/sync/tests/unit/test_engine_abort.js
+++ b/services/sync/tests/unit/test_engine_abort.js
@ -37,7 +37,7 @@ add_task(async function test_processIncoming_abort() {
  );
  meta_global.payload.engines = { rotary: { version: engine.version, syncID } };
  _("Fake applyIncoming to abort.");
-  engine._store.applyIncoming = async function (record) {
+  engine._store.applyIncoming = async function () {
    let ex = {
      code: SyncEngine.prototype.eEngineAbortApplyIncoming,
      cause: "Nooo",
--- a/services/sync/tests/unit/test_errorhandler_1.js
+++ b/services/sync/tests/unit/test_errorhandler_1.js
@ -286,13 +286,10 @@ add_task(async function test_info_collections_login_server_maintenance_error() {
  await configureIdentity({ username: "broken.info" }, server);

  let backoffInterval;
-  Svc.Obs.add(
-    "weave:service:backoff:interval",
-    function observe(subject, data) {
-      Svc.Obs.remove("weave:service:backoff:interval", observe);
-      backoffInterval = subject;
-    }
-  );
+  Svc.Obs.add("weave:service:backoff:interval", function observe(subject) {
+    Svc.Obs.remove("weave:service:backoff:interval", observe);
+    backoffInterval = subject;
+  });

  Assert.ok(!Status.enforceBackoff);
  Assert.equal(Status.service, STATUS_OK);
@ -318,13 +315,10 @@ add_task(async function test_meta_global_login_server_maintenance_error() {
  await configureIdentity({ username: "broken.meta" }, server);

  let backoffInterval;
-  Svc.Obs.add(
-    "weave:service:backoff:interval",
-    function observe(subject, data) {
-      Svc.Obs.remove("weave:service:backoff:interval", observe);
-      backoffInterval = subject;
-    }
-  );
+  Svc.Obs.add("weave:service:backoff:interval", function observe(subject) {
+    Svc.Obs.remove("weave:service:backoff:interval", observe);
+    backoffInterval = subject;
+  });

  Assert.ok(!Status.enforceBackoff);
  Assert.equal(Status.service, STATUS_OK);
--- a/services/sync/tests/unit/test_errorhandler_2.js
+++ b/services/sync/tests/unit/test_errorhandler_2.js
@ -74,13 +74,10 @@ add_task(async function test_crypto_keys_login_server_maintenance_error() {
  Service.collectionKeys.clear();

  let backoffInterval;
-  Svc.Obs.add(
-    "weave:service:backoff:interval",
-    function observe(subject, data) {
-      Svc.Obs.remove("weave:service:backoff:interval", observe);
-      backoffInterval = subject;
-    }
-  );
+  Svc.Obs.add("weave:service:backoff:interval", function observe(subject) {
+    Svc.Obs.remove("weave:service:backoff:interval", observe);
+    backoffInterval = subject;
+  });

  Assert.ok(!Status.enforceBackoff);
  Assert.equal(Status.service, STATUS_OK);
@ -178,13 +175,10 @@ add_task(
    await configureIdentity({ username: "broken.info" }, server);

    let backoffInterval;
-    Svc.Obs.add(
-      "weave:service:backoff:interval",
-      function observe(subject, data) {
-        Svc.Obs.remove("weave:service:backoff:interval", observe);
-        backoffInterval = subject;
-      }
-    );
+    Svc.Obs.add("weave:service:backoff:interval", function observe(subject) {
+      Svc.Obs.remove("weave:service:backoff:interval", observe);
+      backoffInterval = subject;
+    });

    Assert.ok(!Status.enforceBackoff);
    Assert.equal(Status.service, STATUS_OK);
@ -215,13 +209,10 @@ add_task(
    await configureIdentity({ username: "broken.meta" }, server);

    let backoffInterval;
-    Svc.Obs.add(
-      "weave:service:backoff:interval",
-      function observe(subject, data) {
-        Svc.Obs.remove("weave:service:backoff:interval", observe);
-        backoffInterval = subject;
-      }
-    );
+    Svc.Obs.add("weave:service:backoff:interval", function observe(subject) {
+      Svc.Obs.remove("weave:service:backoff:interval", observe);
+      backoffInterval = subject;
+    });

    Assert.ok(!Status.enforceBackoff);
    Assert.equal(Status.service, STATUS_OK);
@ -254,13 +245,10 @@ add_task(
    Service.collectionKeys.clear();

    let backoffInterval;
-    Svc.Obs.add(
-      "weave:service:backoff:interval",
-      function observe(subject, data) {
-        Svc.Obs.remove("weave:service:backoff:interval", observe);
-        backoffInterval = subject;
-      }
-    );
+    Svc.Obs.add("weave:service:backoff:interval", function observe(subject) {
+      Svc.Obs.remove("weave:service:backoff:interval", observe);
+      backoffInterval = subject;
+    });

    Assert.ok(!Status.enforceBackoff);
    Assert.equal(Status.service, STATUS_OK);
@ -291,13 +279,10 @@ add_task(
    await configureIdentity({ username: "broken.keys" }, server);

    let backoffInterval;
-    Svc.Obs.add(
-      "weave:service:backoff:interval",
-      function observe(subject, data) {
-        Svc.Obs.remove("weave:service:backoff:interval", observe);
-        backoffInterval = subject;
-      }
-    );
+    Svc.Obs.add("weave:service:backoff:interval", function observe(subject) {
+      Svc.Obs.remove("weave:service:backoff:interval", observe);
+      backoffInterval = subject;
+    });

    Assert.ok(!Status.enforceBackoff);
    Assert.equal(Status.service, STATUS_OK);
@ -328,13 +313,10 @@ add_task(
    await configureIdentity({ username: "broken.wipe" }, server);

    let backoffInterval;
-    Svc.Obs.add(
-      "weave:service:backoff:interval",
-      function observe(subject, data) {
-        Svc.Obs.remove("weave:service:backoff:interval", observe);
-        backoffInterval = subject;
-      }
-    );
+    Svc.Obs.add("weave:service:backoff:interval", function observe(subject) {
+      Svc.Obs.remove("weave:service:backoff:interval", observe);
+      backoffInterval = subject;
+    });

    Assert.ok(!Status.enforceBackoff);
    Assert.equal(Status.service, STATUS_OK);
@ -368,13 +350,10 @@ add_task(
    engine.enabled = true;

    let backoffInterval;
-    Svc.Obs.add(
-      "weave:service:backoff:interval",
-      function observe(subject, data) {
-        Svc.Obs.remove("weave:service:backoff:interval", observe);
-        backoffInterval = subject;
-      }
-    );
+    Svc.Obs.add("weave:service:backoff:interval", function observe(subject) {
+      Svc.Obs.remove("weave:service:backoff:interval", observe);
+      backoffInterval = subject;
+    });

    Assert.ok(!Status.enforceBackoff);
    Assert.equal(Status.service, STATUS_OK);
--- a/services/sync/tests/unit/test_errorhandler_filelog.js
+++ b/services/sync/tests/unit/test_errorhandler_filelog.js
@ -82,7 +82,7 @@ function readFile(file, callback) {
      uri: NetUtil.newURI(file),
      loadUsingSystemPrincipal: true,
    },
-    function (inputStream, statusCode, request) {
+    function (inputStream, statusCode) {
      let data = NetUtil.readInputStreamToString(
        inputStream,
        inputStream.available()
--- a/services/sync/tests/unit/test_fxa_node_reassignment.js
+++ b/services/sync/tests/unit/test_fxa_node_reassignment.js
@ -46,7 +46,7 @@ function prepareServer(cbAfterTokenFetch) {
  // A server callback to ensure we don't accidentally hit the wrong endpoint
  // after a node reassignment.
  let callback = {
-    onRequest(req, resp) {
+    onRequest(req) {
      let full = `${req.scheme}://${req.host}:${req.port}${req.path}`;
      let expected = config.fxaccount.token.endpoint;
      Assert.ok(
--- a/services/sync/tests/unit/test_history_engine.js
+++ b/services/sync/tests/unit/test_history_engine.js
@ -16,13 +16,13 @@ XPCOMUtils.defineLazyServiceGetter(
  "mozIAsyncHistory"
 );
 async function rawAddVisit(id, uri, visitPRTime, transitionType) {
-  return new Promise((resolve, reject) => {
+  return new Promise(resolve => {
    let results = [];
    let handler = {
      handleResult(result) {
        results.push(result);
      },
-      handleError(resultCode, placeInfo) {
+      handleError(resultCode) {
        do_throw(`updatePlaces gave error ${resultCode}!`);
      },
      handleCompletion(count) {
--- a/services/sync/tests/unit/test_history_store.js
+++ b/services/sync/tests/unit/test_history_store.js
@ -17,7 +17,7 @@ const TIMESTAMP3 = (Date.now() - 123894) * 1000;

 function promiseOnVisitObserved() {
  return new Promise(res => {
-    let listener = new PlacesWeakCallbackWrapper(events => {
+    let listener = new PlacesWeakCallbackWrapper(() => {
      PlacesObservers.removeListener(["page-visited"], listener);
      res();
    });
--- a/services/sync/tests/unit/test_history_tracker.js
+++ b/services/sync/tests/unit/test_history_tracker.js
@ -160,7 +160,7 @@ add_task(async function test_dont_track_expiration() {
  let scorePromise = promiseOneObserver("weave:engine:score:updated");

  // Observe expiration.
-  Services.obs.addObserver(function onExpiration(aSubject, aTopic, aData) {
+  Services.obs.addObserver(function onExpiration(aSubject, aTopic) {
    Services.obs.removeObserver(onExpiration, aTopic);
    // Remove the remaining page to update its score.
    PlacesUtils.history.remove(uriToRemove);
--- a/services/sync/tests/unit/test_hmac_error.js
+++ b/services/sync/tests/unit/test_hmac_error.js
@ -171,7 +171,7 @@ add_task(async function hmac_error_during_node_reassignment() {
  }
  let onSyncFinished = function () {};
  let obs = {
-    observe: function observe(subject, topic, data) {
+    observe: function observe(subject, topic) {
      switch (topic) {
        case "weave:service:sync:error":
          onSyncError();
--- a/services/sync/tests/unit/test_httpd_sync_server.js
+++ b/services/sync/tests/unit/test_httpd_sync_server.js
@ -160,7 +160,7 @@ add_task(async function test_storage_request() {

  async function deleteWBONotExists() {
    let req = localRequest(server, keysURL);
-    server.callback.onItemDeleted = function (username, collection, wboID) {
+    server.callback.onItemDeleted = function () {
      do_throw("onItemDeleted should not have been called.");
    };

--- a/services/sync/tests/unit/test_interval_triggers.js
+++ b/services/sync/tests/unit/test_interval_triggers.js
@ -51,7 +51,7 @@ add_task(async function setup() {
  // Don't remove stale clients when syncing. This is a test-only workaround
  // that lets us add clients directly to the store, without losing them on
  // the next sync.
-  clientsEngine._removeRemoteClient = async id => {};
+  clientsEngine._removeRemoteClient = async () => {};
 });

 add_task(async function test_successful_sync_adjustSyncInterval() {
--- a/services/sync/tests/unit/test_resource.js
+++ b/services/sync/tests/unit/test_resource.js
@ -480,7 +480,7 @@ add_task(async function test_post_override_content_type() {
 add_task(async function test_weave_backoff() {
  _("X-Weave-Backoff header notifies observer");
  let backoffInterval;
-  function onBackoff(subject, data) {
+  function onBackoff(subject) {
    backoffInterval = subject;
  }
  Observers.add("weave:service:backoff:interval", onBackoff);
--- a/services/sync/tests/unit/test_service_sync_401.js
+++ b/services/sync/tests/unit/test_service_sync_401.js
@ -48,7 +48,7 @@ add_task(async function run_test() {
    Svc.PrefBranch.setIntPref("lastPing", Math.floor(Date.now() / 1000));

    let threw = false;
-    Svc.Obs.add("weave:service:sync:error", function (subject, data) {
+    Svc.Obs.add("weave:service:sync:error", function () {
      threw = true;
    });

--- a/services/sync/tests/unit/test_service_verifyLogin.js
+++ b/services/sync/tests/unit/test_service_verifyLogin.js
@ -78,13 +78,10 @@ add_task(async function test_verifyLogin() {
    Service._updateCachedURLs();
    Assert.ok(!Service.status.enforceBackoff);
    let backoffInterval;
-    Svc.Obs.add(
-      "weave:service:backoff:interval",
-      function observe(subject, data) {
-        Svc.Obs.remove("weave:service:backoff:interval", observe);
-        backoffInterval = subject;
-      }
-    );
+    Svc.Obs.add("weave:service:backoff:interval", function observe(subject) {
+      Svc.Obs.remove("weave:service:backoff:interval", observe);
+      backoffInterval = subject;
+    });
    Assert.equal(false, await Service.verifyLogin());
    Assert.ok(Service.status.enforceBackoff);
    Assert.equal(backoffInterval, 42);
--- a/services/sync/tests/unit/test_sync_auth_manager.js
+++ b/services/sync/tests/unit/test_sync_auth_manager.js
@ -1002,7 +1002,7 @@ function mockTokenServer(func) {
    requestLog.addAppender(new Log.DumpAppender());
    requestLog.level = Log.Level.Trace;
  }
-  function MockRESTRequest(url) {}
+  function MockRESTRequest() {}
  MockRESTRequest.prototype = {
    _log: requestLog,
    setHeader() {},
--- a/services/sync/tests/unit/test_syncedtabs.js
+++ b/services/sync/tests/unit/test_syncedtabs.js
@ -87,7 +87,7 @@ let MockClientsEngine = {
    return tabsEngine.clients[id].fxaDeviceId;
  },

-  getClientType(id) {
+  getClientType() {
    return "desktop";
  },
 };
--- a/services/sync/tests/unit/test_syncscheduler.js
+++ b/services/sync/tests/unit/test_syncscheduler.js
@ -92,7 +92,7 @@ add_task(async function setup() {
  // Don't remove stale clients when syncing. This is a test-only workaround
  // that lets us add clients directly to the store, without losing them on
  // the next sync.
-  clientsEngine._removeRemoteClient = async id => {};
+  clientsEngine._removeRemoteClient = async () => {};
  await Service.engineManager.clear();

  validate_all_future_pings();
--- a/services/sync/tests/unit/test_tab_quickwrite.js
+++ b/services/sync/tests/unit/test_tab_quickwrite.js
@ -179,7 +179,7 @@ add_task(async function test_tab_quickWrite_telemetry() {
  let telem = get_sync_test_telemetry();
  telem.payloads = [];
  let oldSubmit = telem.submit;
-  let submitPromise = new Promise((resolve, reject) => {
+  let submitPromise = new Promise(resolve => {
    telem.submit = function (ping) {
      telem.submit = oldSubmit;
      resolve(ping);
--- a/services/sync/tests/unit/test_uistate.js
+++ b/services/sync/tests/unit/test_uistate.js
@ -314,7 +314,7 @@ add_task(async function test_syncError() {

 function observeUIUpdate() {
  return new Promise(resolve => {
-    let obs = (aSubject, aTopic, aData) => {
+    let obs = (aSubject, aTopic) => {
      Services.obs.removeObserver(obs, aTopic);
      const state = UIState.get();
      resolve(state);
--- a/services/sync/tps/extensions/tps/resource/modules/bookmarkValidator.sys.mjs
+++ b/services/sync/tps/extensions/tps/resource/modules/bookmarkValidator.sys.mjs
@ -602,7 +602,7 @@ class ServerRecordInspection {

    await lazy.Async.yieldingForEach(
      this.liveRecords,
-      (record, i) => {
+      record => {
        if (!seen.has(record.id)) {
          // We intentionally don't record the parentid here, since we only record
          // that if the record refers to a parent that doesn't exist, which we
--- a/services/sync/tps/extensions/tps/resource/modules/tabs.sys.mjs
+++ b/services/sync/tps/extensions/tps/resource/modules/tabs.sys.mjs
@ -44,7 +44,7 @@ export var BrowserTabs = {
    // Wait for the tab to load.
    await new Promise(resolve => {
      let mm = browser.ownerGlobal.messageManager;
-      mm.addMessageListener("tps:loadEvent", function onLoad(msg) {
+      mm.addMessageListener("tps:loadEvent", function onLoad() {
        mm.removeMessageListener("tps:loadEvent", onLoad);
        resolve();
      });
--- a/services/sync/tps/extensions/tps/resource/modules/windows.sys.mjs
+++ b/services/sync/tps/extensions/tps/resource/modules/windows.sys.mjs
@ -16,7 +16,7 @@ export var BrowserWindows = {
   * @param aPrivate The private option.
   * @return nothing
   */
-  Add(aPrivate, fn) {
+  Add(aPrivate) {
    return new Promise(resolve => {
      let mainWindow = Services.wm.getMostRecentWindow("navigator:browser");
      let win = mainWindow.OpenBrowserWindow({ private: aPrivate });
--- a/services/sync/tps/extensions/tps/resource/tps.sys.mjs
+++ b/services/sync/tps/extensions/tps/resource/tps.sys.mjs
@ -168,7 +168,7 @@ export var TPS = {
    "nsISupportsWeakReference",
  ]),

-  observe: function TPS__observe(subject, topic, data) {
+  observe: function TPS__observe(subject, topic) {
    try {
      lazy.Logger.logInfo("----------event observed: " + topic);